Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's the problem with quoting on a small part. He discusses this is in
normal anchoring conditions with low winds, etc. He (and I) were only trying
to show the inherent difference in scope needed between those rode types.
That book is considered by most to be THE book on anchoring. Very good read!


Keith

You're just jealous because the voices only talk to me.
________________
-----Original Message-----


> -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1
> scope, combination rope and chain 7:1 and all chain 3:1. So you really
> don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's the problem with quoting on a small part. He discusses this is in
normal anchoring conditions with low winds, etc. He (and I) were only trying
to show the inherent difference in scope needed between those rode types.
That book is considered by most to be THE book on anchoring. Very good read!


Keith

You're just jealous because the voices only talk to me.
________________
-----Original Message-----


> -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1
> scope, combination rope and chain 7:1 and all chain 3:1. So you really
> don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's the problem with quoting on a small part. He discusses this is in
normal anchoring conditions with low winds, etc. He (and I) were only trying
to show the inherent difference in scope needed between those rode types.
That book is considered by most to be THE book on anchoring. Very good read!


Keith

You're just jealous because the voices only talk to me.
________________
-----Original Message-----


> -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1
> scope, combination rope and chain 7:1 and all chain 3:1. So you really
> don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As in many of these threads, when the discussion degenerates to citing
authorities, it indicates that the participant has run out of ideas or
vocabulary, or both.
Frequently, that happens even before this final desperate stage.

I would be very interested in what Bob Austin has to say, if he cares to.

Joe Morgan
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's the problem with quoting on a small part. He discusses this is in
normal anchoring conditions with low winds, etc. He (and I) were only trying
to show the inherent difference in scope needed between those rode types.
That book is considered by most to be THE book on anchoring. Very good read!


Keith

You're just jealous because the voices only talk to me.
________________
-----Original Message-----


> -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1
> scope, combination rope and chain 7:1 and all chain 3:1. So you really
> don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As in many of these threads, when the discussion degenerates to citing
authorities, it indicates that the participant has run out of ideas or
vocabulary, or both.
Frequently, that happens even before this final desperate stage.

I would be very interested in what Bob Austin has to say, if he cares to.

Joe Morgan
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Jeeze you guys.............This is when belonging to this list gets
frustrating.

I seldom drag anchor. I use what works for me and don't care what the rest
of you guys think and I don't have an opinion on how you do it either. If
you drag down on me, then I will not trust you and will move to a place
where I feel safer.

Greg & Jane Bowers
Heart of Gold
www.seaplanetearth.com


-----Original Message-----
From: trawlers-and-trawlering-
[mailto:trawlers-and-trawlering-] On Behalf Of JC
Sent: Wednesday, September 22, 2010 9:02 AM
To: Keith; 'Trawlers & Trawlering List'
Subject: Re: T&T: Use of chain in anchor rodes

Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's the problem with quoting on a small part. He discusses this is in
normal anchoring conditions with low winds, etc. He (and I) were only trying
to show the inherent difference in scope needed between those rode types.
That book is considered by most to be THE book on anchoring. Very good read!


Keith

You're just jealous because the voices only talk to me.
________________
-----Original Message-----


> -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1
> scope, combination rope and chain 7:1 and all chain 3:1. So you really
> don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As in many of these threads, when the discussion degenerates to citing
authorities, it indicates that the participant has run out of ideas or
vocabulary, or both.
Frequently, that happens even before this final desperate stage.

I would be very interested in what Bob Austin has to say, if he cares to.

Joe Morgan
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Jeeze you guys.............This is when belonging to this list gets
frustrating.

I seldom drag anchor. I use what works for me and don't care what the rest
of you guys think and I don't have an opinion on how you do it either. If
you drag down on me, then I will not trust you and will move to a place
where I feel safer.

Greg & Jane Bowers
Heart of Gold
www.seaplanetearth.com


-----Original Message-----
From: trawlers-and-trawlering-
[mailto:trawlers-and-trawlering-] On Behalf Of JC
Sent: Wednesday, September 22, 2010 9:02 AM
To: Keith; 'Trawlers & Trawlering List'
Subject: Re: T&T: Use of chain in anchor rodes

Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. [rba] Dan wrote that:
One of his [Hinz] main points is that the SURGE of a boat (ie: the backward
and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

[rba] I don't have any experience with anchoring in high winds. My
experience with high winds on boats has always been either jogging into the
wind, laying to and drifting with plenty of sea room, or tied to a sturdy
dock. Now that I plan to cruise the coast in my new used trawler, and after
reading about the frequent anchor-dragging experiences, I want to prepare as
best I can for the blow that may be unexpected at the time, but should be
expected over the course of a cruise.

I have been thinking a lot about wind gusts and surge loads, as mentioned by
Dan in his reference to Hinz. I always incorporated either shock cord or
the rubber snubbers into my dock lines for my boats, allowing me to keep the
boat where I wanted it while allowing for the tide without having an
exceptionally long lead. If the surge loads on anchors are a major cause of
anchor dragging, wouldn't a really elastic component in the anchor rode
alleviate those surge loads? I recognize that nylon rope provides some
stretch, but I wouldn't expect it to relieve much of the surge load.

Does anyone use shock cord or rubber snubbers in the anchor rode?

Dick Allen
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's the problem with quoting on a small part. He discusses this is in
normal anchoring conditions with low winds, etc. He (and I) were only trying
to show the inherent difference in scope needed between those rode types.
That book is considered by most to be THE book on anchoring. Very good read!


Keith

You're just jealous because the voices only talk to me.
________________
-----Original Message-----


> -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1
> scope, combination rope and chain 7:1 and all chain 3:1. So you really
> don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As in many of these threads, when the discussion degenerates to citing
authorities, it indicates that the participant has run out of ideas or
vocabulary, or both.
Frequently, that happens even before this final desperate stage.

I would be very interested in what Bob Austin has to say, if he cares to.

Joe Morgan
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Jeeze you guys.............This is when belonging to this list gets
frustrating.

I seldom drag anchor. I use what works for me and don't care what the rest
of you guys think and I don't have an opinion on how you do it either. If
you drag down on me, then I will not trust you and will move to a place
where I feel safer.

Greg & Jane Bowers
Heart of Gold
www.seaplanetearth.com


-----Original Message-----
From: trawlers-and-trawlering-
[mailto:trawlers-and-trawlering-] On Behalf Of JC
Sent: Wednesday, September 22, 2010 9:02 AM
To: Keith; 'Trawlers & Trawlering List'
Subject: Re: T&T: Use of chain in anchor rodes

Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. [rba] Dan wrote that:
One of his [Hinz] main points is that the SURGE of a boat (ie: the backward
and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

[rba] I don't have any experience with anchoring in high winds. My
experience with high winds on boats has always been either jogging into the
wind, laying to and drifting with plenty of sea room, or tied to a sturdy
dock. Now that I plan to cruise the coast in my new used trawler, and after
reading about the frequent anchor-dragging experiences, I want to prepare as
best I can for the blow that may be unexpected at the time, but should be
expected over the course of a cruise.

I have been thinking a lot about wind gusts and surge loads, as mentioned by
Dan in his reference to Hinz. I always incorporated either shock cord or
the rubber snubbers into my dock lines for my boats, allowing me to keep the
boat where I wanted it while allowing for the tide without having an
exceptionally long lead. If the surge loads on anchors are a major cause of
anchor dragging, wouldn't a really elastic component in the anchor rode
alleviate those surge loads? I recognize that nylon rope provides some
stretch, but I wouldn't expect it to relieve much of the surge load.

Does anyone use shock cord or rubber snubbers in the anchor rode?

Dick Allen
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > Does anyone use shock cord or rubber snubbers in the anchor
> rode?

Hi Richard

If you will indulge me, I'm going to respond to your post, even though we don't use shock cord or rubber snubbers. This post reflects our thinking and we practice what we preach. If it isn't to your liking, then you won't hurt our feeling if you do something different; but if you elect to do less, just please don't anchor up wind from us. (grin)

If my recollection is correct, and if you desire I'll pull Heinz's book and look it up, but he says that the surge loads, at most, can only double the force on the ground tackle, over and above the wind load.

It is a shock load that can double and triple the load on the ground tackle. Shock loads are created when the surge is stopped abruptly as when a chain or non-stretchy rope goes tight before the load has fully imposed itself on the rode.

As you know this is something that needs to be avoided at all costs and to do that a nylon snubber (aka: riding stopper) can be used. If sized adequately, you don't need to get fancier than that.

For what it's worth, in harsh conditions we favor a nylon snubber that is at least 30 feet long, and longer is even better.

We size our snubbers, and rope rodes too, so that the load on it does not exceed 15% of the rope's tensile strength. Although it seems everyone has there own favorite loading percentage, even at 15% loading it will still have adequate stretch to cushion the surge loads, plus have the advantage of not being subjected to fiber damage. There are other advantages also.

By the way, for those who might be interested, all of the components in your system should have a minimum WLL that equals or exceeds the highest load that will be imposed on the ground tackle; and, your anchor needs to have the same or more holding power in the poorest bottom that you will anchor in.

To determine the load that will occur on your ground tackle- first determine the force of the wind against the boat in the highest wind speed that you will encounter, multiply this by 130% to account for wind gusts, and then double this figure to take into account surge loads... wow!

You're right, big figure, and it needs big gear. Now if you will be anchoring where the wind speed will not be as severe as what is predicted, or if you will have protection from the seas, this figure can be less. But we have found that planning for the worst, getting gear that can handle these loads and then using it has never created a problem for us. Doing less though, doesn't seem to work as well if the conditions do become as bad as they figured.

Keep in mind that even a quick-appearing, short-lived squall can have 50 - 60 knot winds. The only difference with 50 knot winds from a squall and 50 knot winds from a 2 day storm is that the 2 day storm will have time to more fully develop the seas.

Then too, anchor design and scope play just as an important role.

Now this is for storm gear, for convenience, your everyday stuff can be smaller, if you so choose.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's the problem with quoting on a small part. He discusses this is in
normal anchoring conditions with low winds, etc. He (and I) were only trying
to show the inherent difference in scope needed between those rode types.
That book is considered by most to be THE book on anchoring. Very good read!


Keith

You're just jealous because the voices only talk to me.
________________
-----Original Message-----


> -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1
> scope, combination rope and chain 7:1 and all chain 3:1. So you really
> don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As in many of these threads, when the discussion degenerates to citing
authorities, it indicates that the participant has run out of ideas or
vocabulary, or both.
Frequently, that happens even before this final desperate stage.

I would be very interested in what Bob Austin has to say, if he cares to.

Joe Morgan
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Jeeze you guys.............This is when belonging to this list gets
frustrating.

I seldom drag anchor. I use what works for me and don't care what the rest
of you guys think and I don't have an opinion on how you do it either. If
you drag down on me, then I will not trust you and will move to a place
where I feel safer.

Greg & Jane Bowers
Heart of Gold
www.seaplanetearth.com


-----Original Message-----
From: trawlers-and-trawlering-
[mailto:trawlers-and-trawlering-] On Behalf Of JC
Sent: Wednesday, September 22, 2010 9:02 AM
To: Keith; 'Trawlers & Trawlering List'
Subject: Re: T&T: Use of chain in anchor rodes

Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. [rba] Dan wrote that:
One of his [Hinz] main points is that the SURGE of a boat (ie: the backward
and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

[rba] I don't have any experience with anchoring in high winds. My
experience with high winds on boats has always been either jogging into the
wind, laying to and drifting with plenty of sea room, or tied to a sturdy
dock. Now that I plan to cruise the coast in my new used trawler, and after
reading about the frequent anchor-dragging experiences, I want to prepare as
best I can for the blow that may be unexpected at the time, but should be
expected over the course of a cruise.

I have been thinking a lot about wind gusts and surge loads, as mentioned by
Dan in his reference to Hinz. I always incorporated either shock cord or
the rubber snubbers into my dock lines for my boats, allowing me to keep the
boat where I wanted it while allowing for the tide without having an
exceptionally long lead. If the surge loads on anchors are a major cause of
anchor dragging, wouldn't a really elastic component in the anchor rode
alleviate those surge loads? I recognize that nylon rope provides some
stretch, but I wouldn't expect it to relieve much of the surge load.

Does anyone use shock cord or rubber snubbers in the anchor rode?

Dick Allen
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > Does anyone use shock cord or rubber snubbers in the anchor
> rode?

Hi Richard

If you will indulge me, I'm going to respond to your post, even though we don't use shock cord or rubber snubbers. This post reflects our thinking and we practice what we preach. If it isn't to your liking, then you won't hurt our feeling if you do something different; but if you elect to do less, just please don't anchor up wind from us. (grin)

If my recollection is correct, and if you desire I'll pull Heinz's book and look it up, but he says that the surge loads, at most, can only double the force on the ground tackle, over and above the wind load.

It is a shock load that can double and triple the load on the ground tackle. Shock loads are created when the surge is stopped abruptly as when a chain or non-stretchy rope goes tight before the load has fully imposed itself on the rode.

As you know this is something that needs to be avoided at all costs and to do that a nylon snubber (aka: riding stopper) can be used. If sized adequately, you don't need to get fancier than that.

For what it's worth, in harsh conditions we favor a nylon snubber that is at least 30 feet long, and longer is even better.

We size our snubbers, and rope rodes too, so that the load on it does not exceed 15% of the rope's tensile strength. Although it seems everyone has there own favorite loading percentage, even at 15% loading it will still have adequate stretch to cushion the surge loads, plus have the advantage of not being subjected to fiber damage. There are other advantages also.

By the way, for those who might be interested, all of the components in your system should have a minimum WLL that equals or exceeds the highest load that will be imposed on the ground tackle; and, your anchor needs to have the same or more holding power in the poorest bottom that you will anchor in.

To determine the load that will occur on your ground tackle- first determine the force of the wind against the boat in the highest wind speed that you will encounter, multiply this by 130% to account for wind gusts, and then double this figure to take into account surge loads... wow!

You're right, big figure, and it needs big gear. Now if you will be anchoring where the wind speed will not be as severe as what is predicted, or if you will have protection from the seas, this figure can be less. But we have found that planning for the worst, getting gear that can handle these loads and then using it has never created a problem for us. Doing less though, doesn't seem to work as well if the conditions do become as bad as they figured.

Keep in mind that even a quick-appearing, short-lived squall can have 50 - 60 knot winds. The only difference with 50 knot winds from a squall and 50 knot winds from a 2 day storm is that the 2 day storm will have time to more fully develop the seas.

Then too, anchor design and scope play just as an important role.

Now this is for storm gear, for convenience, your everyday stuff can be smaller, if you so choose.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. On 22/09/2010 23:01, Rudy and Jill wrote: Snip ,,,,
> Now this is for storm gear, for convenience, your everyday stuff can be smaller, if you so choose.
>
Perhaps I'm missing something here. Why would you have an anchor rode
that won't hold the boat in every condition you expect to meet? I never
understand why boats equipped with two anchors at the bow have two
different sizes. If you need an xx sized anchor to cope with the
unexpected, why have a smaller one that may let you down? I genuinely
don't understand this so if someone can enlighten me I'd be grateful.

Paige
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's the problem with quoting on a small part. He discusses this is in
normal anchoring conditions with low winds, etc. He (and I) were only trying
to show the inherent difference in scope needed between those rode types.
That book is considered by most to be THE book on anchoring. Very good read!


Keith

You're just jealous because the voices only talk to me.
________________
-----Original Message-----


> -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1
> scope, combination rope and chain 7:1 and all chain 3:1. So you really
> don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As in many of these threads, when the discussion degenerates to citing
authorities, it indicates that the participant has run out of ideas or
vocabulary, or both.
Frequently, that happens even before this final desperate stage.

I would be very interested in what Bob Austin has to say, if he cares to.

Joe Morgan
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Jeeze you guys.............This is when belonging to this list gets
frustrating.

I seldom drag anchor. I use what works for me and don't care what the rest
of you guys think and I don't have an opinion on how you do it either. If
you drag down on me, then I will not trust you and will move to a place
where I feel safer.

Greg & Jane Bowers
Heart of Gold
www.seaplanetearth.com


-----Original Message-----
From: trawlers-and-trawlering-
[mailto:trawlers-and-trawlering-] On Behalf Of JC
Sent: Wednesday, September 22, 2010 9:02 AM
To: Keith; 'Trawlers & Trawlering List'
Subject: Re: T&T: Use of chain in anchor rodes

Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. [rba] Dan wrote that:
One of his [Hinz] main points is that the SURGE of a boat (ie: the backward
and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

[rba] I don't have any experience with anchoring in high winds. My
experience with high winds on boats has always been either jogging into the
wind, laying to and drifting with plenty of sea room, or tied to a sturdy
dock. Now that I plan to cruise the coast in my new used trawler, and after
reading about the frequent anchor-dragging experiences, I want to prepare as
best I can for the blow that may be unexpected at the time, but should be
expected over the course of a cruise.

I have been thinking a lot about wind gusts and surge loads, as mentioned by
Dan in his reference to Hinz. I always incorporated either shock cord or
the rubber snubbers into my dock lines for my boats, allowing me to keep the
boat where I wanted it while allowing for the tide without having an
exceptionally long lead. If the surge loads on anchors are a major cause of
anchor dragging, wouldn't a really elastic component in the anchor rode
alleviate those surge loads? I recognize that nylon rope provides some
stretch, but I wouldn't expect it to relieve much of the surge load.

Does anyone use shock cord or rubber snubbers in the anchor rode?

Dick Allen
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > Does anyone use shock cord or rubber snubbers in the anchor
> rode?

Hi Richard

If you will indulge me, I'm going to respond to your post, even though we don't use shock cord or rubber snubbers. This post reflects our thinking and we practice what we preach. If it isn't to your liking, then you won't hurt our feeling if you do something different; but if you elect to do less, just please don't anchor up wind from us. (grin)

If my recollection is correct, and if you desire I'll pull Heinz's book and look it up, but he says that the surge loads, at most, can only double the force on the ground tackle, over and above the wind load.

It is a shock load that can double and triple the load on the ground tackle. Shock loads are created when the surge is stopped abruptly as when a chain or non-stretchy rope goes tight before the load has fully imposed itself on the rode.

As you know this is something that needs to be avoided at all costs and to do that a nylon snubber (aka: riding stopper) can be used. If sized adequately, you don't need to get fancier than that.

For what it's worth, in harsh conditions we favor a nylon snubber that is at least 30 feet long, and longer is even better.

We size our snubbers, and rope rodes too, so that the load on it does not exceed 15% of the rope's tensile strength. Although it seems everyone has there own favorite loading percentage, even at 15% loading it will still have adequate stretch to cushion the surge loads, plus have the advantage of not being subjected to fiber damage. There are other advantages also.

By the way, for those who might be interested, all of the components in your system should have a minimum WLL that equals or exceeds the highest load that will be imposed on the ground tackle; and, your anchor needs to have the same or more holding power in the poorest bottom that you will anchor in.

To determine the load that will occur on your ground tackle- first determine the force of the wind against the boat in the highest wind speed that you will encounter, multiply this by 130% to account for wind gusts, and then double this figure to take into account surge loads... wow!

You're right, big figure, and it needs big gear. Now if you will be anchoring where the wind speed will not be as severe as what is predicted, or if you will have protection from the seas, this figure can be less. But we have found that planning for the worst, getting gear that can handle these loads and then using it has never created a problem for us. Doing less though, doesn't seem to work as well if the conditions do become as bad as they figured.

Keep in mind that even a quick-appearing, short-lived squall can have 50 - 60 knot winds. The only difference with 50 knot winds from a squall and 50 knot winds from a 2 day storm is that the 2 day storm will have time to more fully develop the seas.

Then too, anchor design and scope play just as an important role.

Now this is for storm gear, for convenience, your everyday stuff can be smaller, if you so choose.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. On 22/09/2010 23:01, Rudy and Jill wrote: Snip ,,,,
> Now this is for storm gear, for convenience, your everyday stuff can be smaller, if you so choose.
>
Perhaps I'm missing something here. Why would you have an anchor rode
that won't hold the boat in every condition you expect to meet? I never
understand why boats equipped with two anchors at the bow have two
different sizes. If you need an xx sized anchor to cope with the
unexpected, why have a smaller one that may let you down? I genuinely
don't understand this so if someone can enlighten me I'd be grateful.

Paige
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > Perhaps I'm missing something here. Why would you have an anchor rode
> that won't hold the boat in every condition you expect to meet? I never
> understand why boats equipped with two anchors at the bow have two
> different sizes. If you need an xx sized anchor to cope with the
> unexpected, why have a smaller one that may let you down? I genuinely
> don't understand this so if someone can enlighten me I'd be grateful.
>
Rightfully or wrongfully I have gone to sleep at anchor "knowing" that I was
tucked in nice protective cove and that there was no chance of a blow
happening. So I drop an adequate hook, and adequate scope to keep the swing
range low. I guess I wasn't expecting the unexpected.

But then most of my cruising has been up and down the ICW.

-- Jim
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.

Rudy and list, I use some chain and then rope rode. I have one boat that
doesn't have a windless and if I commonly anchor in say 10ft-12ft and the bow
is 5ft-6ft high, I have 15' of chain before It gets to the anchor roller.
I want the anchor broken out before I have to handle the chain. I have on
occasion had longer chain and trying to attach it to a cleat in a bucking
bow environment is no fun. Can you say "count your fingers"? So, on that boat
I get along fine with about 15ft of chain.

During nor'easters and hurricanes, I put out an East anchor and a West
anchor, each with about 100' of rope rode and 15ft of chain and they attach
to a 20ft-25ft pendent on the bow. At the attach point I have a 20# kellet
anchor. It may do no good as Rudy says in a hard blow, but it does seem to
hold the pendent and anchor rodes down when the wind swings around as
hurricanes do, to the point that I have never had the rodes wrapped around the
keel or rudder, etc. That one is a sailboat. It works good for me on that
boat.
Ed
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's simply not true. Depends on the length of the rode as well. More
rode will give you more catenary at higher wind speeds.


Keith

If quitters never win, and winners never quit, then who is the fool who
said, "Quit while you're ahead?"
________________
-----Original Message-----


Those that have this thought might want to reconsider. In light conditions
chain, due to its cantenary, can keep the boat in a tighter swing radius,
but as the wind increases, the catenary decreases until somewhere around 40
knots the catenary is no more. So chain or rope, it doesn't matter.

Rudy
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> That's simply not true. Depends on the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

Rudy's point is that as the wind picks up, there always comes a point where
the wind forces totally overcome the catanery effect of the chain, and the
rode goes bar tight. That is simply the laws of physics that we cannot
change.

As such, Rudy was correct in saying that at those high wind speeds, any
catenary eventually disappears, and at that point, it doesn't matter whether
the rode is rope or chain (ignoring the shock absorbing ability for rope
rode, or abrasion resistance for chain).

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing. They
all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.

I think the point that needs to be addressed is that the catenary disappears,
not whether it disappears at 40 knots or 43 knots or 37 knots. Without a
catenary the entire concept of anchoring changes and the anchor's ability to
remain set is entirely dependent on the rode-to-bottom angle, plus there is a
need for some means to absorb 100% of the surge loads.

If the wind speed increases, there is even more force against the boat, thus
the rode, straightening the rode even more, or if already straight, stretching
it tighter.

But, if I'm overlooking something, which is entirely possible in a short post,
I'm all eyes.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Back to your direct quote: "In light conditions chain, due to its catenary,
can keep the boat in a tighter swing radius, but as the wind increases, the
catenary decreases until somewhere around 40 knots the catenary is no more.
So chain or rope, it doesn't matter."

You put out more rode in higher wind conditions to increase or keep the same
angle of the anchor at the bottom. You'd have to let out a LOT more rope
than chain to achieve this.

The scope recommendations in "The Complete Book of Anchoring and Mooring"
state that to achieve adequate holding, all rope rodes need a 10:1 scope,
combination rope and chain 7:1 and all chain 3:1. So you really don't think
it makes a difference between rope and chain rodes? I guarantee you my 100'
of all chain will have more catenary than any rode with chain at the same
wind velocity. I also guarantee that as the wind picks up, I will let out
more chain and I will keep my catenary up to some point. But you can't
really think that "So chain or rope, it doesn't matter." Can you?

Also, if you're looking at Hinz's table of all chain catenary, realize that
it's a hypothetical situation with 100' of chain for rode. He states that
the boat could let out 200' and double the catenary sag and holding values.
Also, heavier or larger chain would perform better than lighter chain.

There's no magic at 40 knots that makes every rode bar tight.


Keith

Health nuts are going to feel stupid someday, lying in hospitals dying of
nothing.
________________
-----Original Message-----


> That's simply not true. Depends on
> the length of the rode as well. More
> rode will give you more catenary at higher wind speeds.

No Keith, I have to disagree, respectfully of course. Catenaries, in chain
sized relative to a boat's size, disappears around 40 knots.

Longer chain, heavier chain or using a kellet, it is all the same thing.
They all will require somewhat higher wind speeds for the rode to loose its
catenary, but again, not as much as you'd think, 3-5 knots, maybe a little
more, maybe a little less. With rope, it occurs with even lower wind speeds.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. The catenary is a result of two forces. The horizontal force of the boat on
the chain and the vertical weight of the chain. The horizontal force is
product of wind, wave,and current acting on the boat's geometry. This is
forces rises exponentially with the wind speed. The vertical force is result
if the length of the chain. This force is what puts the bend in the catenary.
Because the horizontal force is exponential, a relatively small increase in
wind speed results in a relatively large increase in the horizontal force.
Review of Table 5-5 in Hintz's book shows that a 4 fold increase in wind speed
results in a 16 fold increase in the horizontal force. Also the stress in the
chain is a combination of the vertical and horizontal forces so is actually
greater than just the horizontal force.

So while it is correct that you can extend the chain to try to get the
catenary back, you are fighting a force that is exponentially stronger. I
can't see the math that will win that game.

Best regards,

--Jim
Carol Marie
Puget Trawler 40
Tacoma, Washington



On Sep 21, 2010, at 3:24 PM, Keith wrote:
> ....
>
> Also, if you're looking at Hinz's table of all chain catenary, realize that
> it's a hypothetical situation with 100' of chain for rode. He states that
> the boat could let out 200' and double the catenary sag and holding values.
> Also, heavier or larger chain would perform better than lighter chain.
>
> There's no magic at 40 knots that makes every rode bar tight.
>
>
> Keith
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1 scope,
> combination rope and chain 7:1 and all chain 3:1. So you really don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
www.BoatMoves.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As a relatively new boater, I find this to be a very interesting subject. I do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. When the boat is on motion you have momentum forces adding to the load on
the anchor and rode. Momentum forces are the product of the mass (weight) of
the boat and it's speed. Again, this is additive to the horizontal wind
load.

Hintz does say that doubling the length of the rode (page 114) but at 40
feet the height of the catenary is zero and two times zero is still zero.
Please pardon me if I missed something, it's getting late.

The statement about adding shock absorption with nylon rode is a good
recommendation.
--Jim

Sent via DROID on Verizon Wireless

-----Original message-----
From: Dan Freedman <>
To: trawlers-and-
Sent: Wed, Sep 22, 2010 04:32:07 GMT+00:00
Subject: Re: T&T: Use of chain in anchor rodes

As a relatively new boater, I find this to be a very interesting subject. I
do
not have the experience to comment directly, but I can quote Mr. Hinz on the
subject.

In "The Complete Book of Anchoring and Mooring", Revised 2nd Edition, Earl
R.
Hinz supports the notion that catenary disappears in high wind. He also
supports the notion that catenary can be restored by letting out more chain.

BUT

One of his main points is that the SURGE of a boat (ie: the backward and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

Dan

--
Dan Freedman, Sea Spirit Passagemaker 60
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Ah, religion. And complete with references to the holy books...

"That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1 is
pure poppycock!"

Correct. Pure poppycock.

And, Earl Hinz' book, "The Compete Guide to Anchoring and Mooring," does not
make that claim. He refers to a scope of 3:1 on all chain as a *minimum* in
*calm* conditions. He refers to a scope of 7:1 all chain being roughly
equivalent to 10:1 all-rope. One must read the text to interpret the tables
and understand the context and the net message.

There is another book I commend for the list's consideration, called "The
Complete Anchoring Handbook," by Alain Poiraud, and Achim and Erika
Ginsburg-Klemmt. These authors include an essay by Alain Fraysse in Appendix
I. The essay does an excellent job (with some advanced algebra and a little
bit of trigonometry) of analyzing the theoretical behavior of rode catenary in
static and dynamic conditions, and the effect of catenary on shank-to-bottom
angle. Shank-to-bottom angle is, when all is said and done, the critical
*controllable* variable. Fraysse suggests that kellets are most effective
when placed closest to the anchor, at about 20 percent of the length of the
rode. Fraysse discusses the dynamic performance of a hybrid rode (short
length of chain spliced to nylon three-strand rope) for surge loads and drift,
and concludes that the performance of this configuration equals and exceeds
all chain with kellet.

Both of the books are primarily experiential, backed up with theory and math.
Hinz' presents more conclusions and less math and might be an easier read for
those disinclined towards the math. Hinz' writes about US and pacific waters
and the others write mostly about European waters. Hinz' writes in US units
of measure, the other in metrics (mostly converted).

The net is, both books fundamentally agree with each other, and both agree
with Rudy.

Thus endeth my sermon! Amen!

Peg and Jim Healy aboard Sanctuary
Currently at Rock Creek, Pasadena, MD
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. In several of his books, the old English circumnavigator Eric Hiscock
recommended a 3:1 scope with an all-chain rode in normal conditions, going to
greater scope in storm conditions. But then, he also believed in CQR anchors
so I don't know if we should trust his judgment.

I shall now retire to the other room and put on my asbestos underwear.

Regards,
Randy Pickelmann
MORNING STAR
lying in Clearwater, FL
www.CruisingMorningStar.com
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. That's the problem with quoting on a small part. He discusses this is in
normal anchoring conditions with low winds, etc. He (and I) were only trying
to show the inherent difference in scope needed between those rode types.
That book is considered by most to be THE book on anchoring. Very good read!


Keith

You're just jealous because the voices only talk to me.
________________
-----Original Message-----


> -----Original Message-----
> The scope recommendations in "The Complete Book of Anchoring and Mooring"
> state that to achieve adequate holding, all rope rodes need a 10:1
> scope, combination rope and chain 7:1 and all chain 3:1. So you really
> don't
think
> it makes a difference between rope and chain rodes?

After reading that quote, I can say I will never bother to look at that
book! If that was an accurate statement, it showed that the author didn't
know what he was talking about. After all, paper doesn't refuse ink!

That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
is pure poppycock! The author has certainly not swung on an all chain 3:1
rode in a fifty knot blow or he would know better. With a 3:1 scope in that
wind, the chain would be bar tight, and at the high angle of the
ridiculously short 3:1 scope, the anchor would pull out and be dancing
across the bottom. You won't catch me hanging any boat I am working on with
such a short scope in any blow above 15 knots.

While anchor scopes between 5:1 and 7:1 are what are normally recommended,
when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
This is the number where the angle of pull on the anchor becomes almost
horizontal when the rode is stretched tight (chain or rope). If anyone
wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be on
the nearby jetty with a camera to record the final result!

Kevin
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. As in many of these threads, when the discussion degenerates to citing
authorities, it indicates that the participant has run out of ideas or
vocabulary, or both.
Frequently, that happens even before this final desperate stage.

I would be very interested in what Bob Austin has to say, if he cares to.

Joe Morgan
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. Jeeze you guys.............This is when belonging to this list gets
frustrating.

I seldom drag anchor. I use what works for me and don't care what the rest
of you guys think and I don't have an opinion on how you do it either. If
you drag down on me, then I will not trust you and will move to a place
where I feel safer.

Greg & Jane Bowers
Heart of Gold
www.seaplanetearth.com


-----Original Message-----
From: trawlers-and-trawlering-
[mailto:trawlers-and-trawlering-] On Behalf Of JC
Sent: Wednesday, September 22, 2010 9:02 AM
To: Keith; 'Trawlers & Trawlering List'
Subject: Re: T&T: Use of chain in anchor rodes

Keith,

I believe the part about the "the voices"!

JC
----- Original Message -----
From: "Keith" <>
To: "'Trawlers & Trawlering List'"

Sent: Wednesday, September 22, 2010 8:58 AM
Subject: Re: T&T: Use of chain in anchor rodes


> That's the problem with quoting on a small part. He discusses this is in
> normal anchoring conditions with low winds, etc. He (and I) were only
> trying
> to show the inherent difference in scope needed between those rode types.
> That book is considered by most to be THE book on anchoring. Very good
> read!
>
>
> Keith
>
> You're just jealous because the voices only talk to me.
> ________________
> -----Original Message-----
>
>
>> -----Original Message-----
>> The scope recommendations in "The Complete Book of Anchoring and Mooring"
>> state that to achieve adequate holding, all rope rodes need a 10:1
>> scope, combination rope and chain 7:1 and all chain 3:1. So you really
>> don't
> think
>> it makes a difference between rope and chain rodes?
>
> After reading that quote, I can say I will never bother to look at that
> book! If that was an accurate statement, it showed that the author didn't
> know what he was talking about. After all, paper doesn't refuse ink!
>
> That claim that an all chain rode of 3:1 is as good as a rope rode at 10:1
> is pure poppycock! The author has certainly not swung on an all chain 3:1
> rode in a fifty knot blow or he would know better. With a 3:1 scope in
> that
> wind, the chain would be bar tight, and at the high angle of the
> ridiculously short 3:1 scope, the anchor would pull out and be dancing
> across the bottom. You won't catch me hanging any boat I am working on
> with
> such a short scope in any blow above 15 knots.
>
> While anchor scopes between 5:1 and 7:1 are what are normally recommended,
> when the wind kicks up beyond 25 knots, I want a scope of at least 10:1.
> This is the number where the angle of pull on the anchor becomes almost
> horizontal when the rode is stretched tight (chain or rope). If anyone
> wanted to hang on a hook with a 3:1 scope in a real blow, I'd like to be
> on
> the nearby jetty with a camera to record the final result!
>
> Kevin
> _______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. [rba] Dan wrote that:
One of his [Hinz] main points is that the SURGE of a boat (ie: the backward
and
forward movement of the boat away from and toward the anchor) as the wind
gusts, can exert tremendous amounts of force on the boat and anchoring
equipment (p 22-24 of the book). These forces are greatest as the boat comes
to a fairly abrupt stop at the end of the rode. He calculates those forces
as
being several times higher than the wind load, in a hard blow.

He goes on to expressly point out that the stretch of at least some amount
of
nylon rode is very useful in a hard blow, in that it will distribute that
deceleration over a longer period of time than all-chain would, thereby
lowering the surge forces dramatically.

[rba] I don't have any experience with anchoring in high winds. My
experience with high winds on boats has always been either jogging into the
wind, laying to and drifting with plenty of sea room, or tied to a sturdy
dock. Now that I plan to cruise the coast in my new used trawler, and after
reading about the frequent anchor-dragging experiences, I want to prepare as
best I can for the blow that may be unexpected at the time, but should be
expected over the course of a cruise.

I have been thinking a lot about wind gusts and surge loads, as mentioned by
Dan in his reference to Hinz. I always incorporated either shock cord or
the rubber snubbers into my dock lines for my boats, allowing me to keep the
boat where I wanted it while allowing for the tide without having an
exceptionally long lead. If the surge loads on anchors are a major cause of
anchor dragging, wouldn't a really elastic component in the anchor rode
alleviate those surge loads? I recognize that nylon rope provides some
stretch, but I wouldn't expect it to relieve much of the surge load.

Does anyone use shock cord or rubber snubbers in the anchor rode?

Dick Allen
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > Does anyone use shock cord or rubber snubbers in the anchor
> rode?

Hi Richard

If you will indulge me, I'm going to respond to your post, even though we don't use shock cord or rubber snubbers. This post reflects our thinking and we practice what we preach. If it isn't to your liking, then you won't hurt our feeling if you do something different; but if you elect to do less, just please don't anchor up wind from us. (grin)

If my recollection is correct, and if you desire I'll pull Heinz's book and look it up, but he says that the surge loads, at most, can only double the force on the ground tackle, over and above the wind load.

It is a shock load that can double and triple the load on the ground tackle. Shock loads are created when the surge is stopped abruptly as when a chain or non-stretchy rope goes tight before the load has fully imposed itself on the rode.

As you know this is something that needs to be avoided at all costs and to do that a nylon snubber (aka: riding stopper) can be used. If sized adequately, you don't need to get fancier than that.

For what it's worth, in harsh conditions we favor a nylon snubber that is at least 30 feet long, and longer is even better.

We size our snubbers, and rope rodes too, so that the load on it does not exceed 15% of the rope's tensile strength. Although it seems everyone has there own favorite loading percentage, even at 15% loading it will still have adequate stretch to cushion the surge loads, plus have the advantage of not being subjected to fiber damage. There are other advantages also.

By the way, for those who might be interested, all of the components in your system should have a minimum WLL that equals or exceeds the highest load that will be imposed on the ground tackle; and, your anchor needs to have the same or more holding power in the poorest bottom that you will anchor in.

To determine the load that will occur on your ground tackle- first determine the force of the wind against the boat in the highest wind speed that you will encounter, multiply this by 130% to account for wind gusts, and then double this figure to take into account surge loads... wow!

You're right, big figure, and it needs big gear. Now if you will be anchoring where the wind speed will not be as severe as what is predicted, or if you will have protection from the seas, this figure can be less. But we have found that planning for the worst, getting gear that can handle these loads and then using it has never created a problem for us. Doing less though, doesn't seem to work as well if the conditions do become as bad as they figured.

Keep in mind that even a quick-appearing, short-lived squall can have 50 - 60 knot winds. The only difference with 50 knot winds from a squall and 50 knot winds from a 2 day storm is that the 2 day storm will have time to more fully develop the seas.

Then too, anchor design and scope play just as an important role.

Now this is for storm gear, for convenience, your everyday stuff can be smaller, if you so choose.

Rudy
Briney Bug, Panama City, Fl
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. On 22/09/2010 23:01, Rudy and Jill wrote: Snip ,,,,
> Now this is for storm gear, for convenience, your everyday stuff can be smaller, if you so choose.
>
Perhaps I'm missing something here. Why would you have an anchor rode
that won't hold the boat in every condition you expect to meet? I never
understand why boats equipped with two anchors at the bow have two
different sizes. If you need an xx sized anchor to cope with the
unexpected, why have a smaller one that may let you down? I genuinely
don't understand this so if someone can enlighten me I'd be grateful.

Paige
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > Perhaps I'm missing something here. Why would you have an anchor rode
> that won't hold the boat in every condition you expect to meet? I never
> understand why boats equipped with two anchors at the bow have two
> different sizes. If you need an xx sized anchor to cope with the
> unexpected, why have a smaller one that may let you down? I genuinely
> don't understand this so if someone can enlighten me I'd be grateful.
>
Rightfully or wrongfully I have gone to sleep at anchor "knowing" that I was
tucked in nice protective cove and that there was no chance of a blow
happening. So I drop an adequate hook, and adequate scope to keep the swing
range low. I guess I wasn't expecting the unexpected.

But then most of my cruising has been up and down the ICW.

-- Jim
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe. > Perhaps I'm missing something here. Why would you
> have an anchor rode that won't hold the boat in every
> condition you expect to meet?

Paige, I think you've hit the nail on the head.

But, others don't understand this, or don't think about it. Some have that "it
probably won't happen" attitude, instead of "better safe than sorry"
attitude.

Unfortunately, many are fooled by those generic anchoring charts, little
realizing that those charts are often for winds UNDER 30 knots WITH some
protections from seas AND when anchoring in sand.

For those who don't know, an anchor with a 45 degree fluke angle, in soft mud,
has only 1/2 the holding power as does an anchor with a 32 degree fluke angle
used in sand; if the fluke angle is 32 degrees and used in soft mud, the
anchor's holding power is only 1/4 of that when used in sand.

Others choose their ground tackle based on what their windlass can handle, not
stopping to realize that the windlass may be sized for rodes that are for mild
to moderate conditions.

Others don't want the bother of manhandling hefty gear; they can't all be a
Jill.

Then too, some boats just can't carry the weight of that size gear on the bow;
sailboats especially can loose performance if they do, particularly in
tacking.

I'm sure that there are other reasons; some folks will use any reason to
justify neglecting good seamanship. The lucky ones become aware of this
shortcoming and the ones that are luckier still do something about it.

Since a squall can produce high winds, we think that the main bower should be
able to withstand this hefty of a load and do it in the poorest holding bottom
that will be anchored in. In addition, gear that is hefty enough to withstand
high winds for days should also be onboard. In addition to being able to
withstand these conditions, another set of hefty-enough ground tackle pays
dividends in many ways.

In fact, we think that this gear should be the first items purchased and the
boat shouldn't even be launched until it is onboard.

I guess, to be practical, we don't mind what size someones main bower is, as
long as they have adequate harsh conditions gear onboard and use it. The
problem is that the more difficult it is to get to, deploy and retrieve, the
less likely it is to get used, and quite often it is the rest of us that has
to deal with the consequences also.

Preaching? Probably, but maybe someone who needs the sermon will hear it. To
those who don't, our appologies.

Rudy and Jill
Briney Bug, Panama City, Fl.
_______________________________________________
___________________________________________________

Posted on the Trawlers-and-Trawlering mailing list. Go to http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering to subscribe.