Line size for anchor bridle

[cabo_sailor]

I'm about to make up a new anchor chain bridle and could use some input on the size of the 3-strand.

My dock lines, secondary anchor line are all 5/8 three strand. The chain rode is 5/16 with a 45 lb CQR.

In the past I've made up the bridle with 1/2 in 3-strand to encourage stretch. It's about 20 ft long.

Question: Should I be using 1/2 or 5/8? Does it really make any difference?

Thanks,
Rich


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[Vasco]

I use 5/8 nylon with 3/8 chain and 45# Manson Supreme. B393 about about 23000 pounds loaded.

[steve77]

Our boat is considerably heavier than yours, and I use two 25 foot lengths of 5/8" line spliced to a Mantus chain hook. I use the 5/8" to encourage stretch, like you. I would think that for your application, two lengths of 1/2" would be fine. Just get a secure chain hook so it doesn't slip off. And use chafe guard where the bridle goes through your fairleads. I use fire hose for this.

I'll add the caveat that the folks at Mantus make a bridle to fit your boat, and they use 5/8" line.

Cheers!

Steve

[model 10]

Seems like the smaller stuff wears out to fast. I started using 5/8 and it lasts quite a while before you see broken fibers. With our boat being smaller than yours, you will see lots of stretch in 5/8.
I'm interested in your thoughts about 3 strand and how it twists up in the chain when it comes taught. When it does that, you loose quite a bit of your snubbers length. I had to go to a double braid snubber to get rid of the twist problem.

[belizesailor]

5/8" has a WLL of about 1,100lbs, 1/2" about 700. Either should be sufficient, but for a heavy displacement boat 5/8 might give you a bit more peace of mind.

Ive gone forward and pulled on the bridle to get a feel for the load in high winds on a variety of boats and never felt any load even approaching 700lbs. Nothing scientific, but just empirical experience. Obviously in really bad conditions you could likely get shock loads in that range...esp on a heavier mono.

[zboss]

We have two bridles. Both use the mantus chain hook. One uses 25 feet on each leg of 5/8" 3 strand. The other uses 50 feet of 3/8" 3 strand on each leg.

The 3/8" has a LOT more stretch. We have had that line in 40 knots winds with our spade anchor and pretty high standing waves and its a champ. The boat hobby-horses less in heavy wave action than using the 5/8" three strand.

I would add... the 3/8" line is very cheap to replace, so we do whenever it occurs to us that it may be needed.

[cabo_sailor]

Zboss,
I was under the impression that smaller diameter line would have more stretch. Do you still use the heavier bridle? For the 3/8 why did you use 50 ft instead the more easily handled 25 ft?

Rich


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[cabo_sailor]

Originally Posted by Guy

Seems like the smaller stuff wears out to fast. I started using 5/8 and it lasts quite a while before you see broken fibers. With our boat being smaller than yours, you will see lots of stretch in 5/8.

I'm interested in your thoughts about 3 strand and how it twists up in the chain when it comes taught. When it does that, you loose quite a bit of your snubbers length. I had to go to a double braid snubber to get rid of the twist problem.

Guy,
I've not had a problem with twist. Perhaps that's because up until now I've not used a bridle. I've been using a single 25 ft 3-strand line with a chain hook. I'm looking at the bridle because the chain hook can fall off too easily. So far the Mantus seems to have the most secure hook.

Rich


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[wrwakefield]

Originally Posted by cabo_sailor

I'm about to make up a new anchor chain bridle and could use some input on the size of the 3-strand.

My dock lines, secondary anchor line are all 5/8 three strand. The chain rode is 5/16 with a 45 lb CQR.

In the past I've made up the bridle with 1/2 in 3-strand to encourage stretch. It's about 20 ft long.

Question: Should I be using 1/2 or 5/8? Does it really make any difference?

Thanks,
Rich


Sent from my iPhone using Cruisers Sailing Forum

Hi Rich,

I've come to the conclusion that the 'right' formula for an anchor bridle is one that will hold up in the worse conditions you expect. [It is no fun- even dangerous- setting or replacing a bridle when conditions have the chain bar tight...]

On our present boat I attach the middle of a ~80ft length of 5/8" 3-strand nylon [our boat displaces 22 tons loaded] to the anchor chain with a cow-hitch for our bridle. [The above is an excerpt from a recent related post- which contains more details including deployment variations and storm rig...] This on an all chain rode. [5/16" Grade 43]

[Edit] It may be worth mentioning we rarely if ever anchor in less than 30ft depth [at low water- with a 15-20ft tidal variation in current cruising grounds...] We typically anchor in 60-90ft...

We deploy our bridle every time we anchor overnight. Why every time? Because I'm lazy; I don't want to get up in the middle of the night because the conditions changed... [Deployment only takes 2-3 minutes total including take-down/flake/stow.]

In case this is helpful.

Cheers!

Bill

[Cheechako]

I'd probably go with 5/8, but 1/2 would work. In a hard blow they stretch a lot... even 5/8 so my thought is for that situation. But also keep in mind how well 5/8 fits your cleats...

[cabo_sailor]

Originally Posted by Cheechako

I'd probably go with 5/8, but 1/2 would work. In a hard blow they stretch a lot... even 5/8 so my thought is for that situation. But also keep in mind how well 5/8 fits your cleats...

5/8 fits the cleats easily. My concern is attaching two such lines to the Mantus hook without it being too cramped. Our boat is around 24 K lbs but our waters are shallow. Typical anchorage is only about 10-20 ft.


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[zboss]

Originally Posted by cabo_sailor

Zboss,
I was under the impression that smaller diameter line would have more stretch. Do you still use the heavier bridle? For the 3/8 why did you use 50 ft instead the more easily handled 25 ft?

Rich


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It does... lots more stretch. I can't explain it but the boat doesn't bounce around nearly as much with the 3/8" nylon vs. the 5/8" nylon. With that said, if we are expecting weather we usually switch to the 5/8" or preload the 5/8" behind the 3/8" so if the 3/8" breaks we have the 5/8" that can take the load.

I use 50 feet so I can periodically move it to avoid chaffing a single spot - we start out at 25 feet on each side then move out 1 or so feet at a time. If we only had 25 on each leg we would not have that option. The 3/8" is very easy to manage at 50 feet long (its actually probably closer to 45 on each leg because I put an eye at the end).

[model 10]

Originally Posted by cabo_sailor

5/8 fits the cleats easily. My concern is attaching two such lines to the Mantus hook without it being too cramped. Our boat is around 24 K lbs but our waters are shallow. Typical anchorage is only about 10-20 ft.
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I must be in the super minority. I had trouble with the Mantus hook. It came off twice in fluky anchorages. I got the plastic safety device and it broke. So now I use the Mantus hook on one snubber and a hitch to the chain with another snubber. That way you get a back-up for that hook and you can make it a progressive snubber with different size line for each one.

[zboss]

Originally Posted by Guy

I must be in the super minority. I had trouble with the Mantus hook. It came off twice in fluky anchorages. I got the plastic safety device and it broke. So now I use the Mantus hook on one snubber and a hitch to the chain with another snubber. That way you get a back-up for that hook and you can make it a progressive snubber with different size line for each one.

My gate broke too - I suspect the sun makes them brittle. I guess that's why they are selling replacements for $4 now. I ended up buying a new one and a backup.

[model 10]

Originally Posted by zboss

My gate broke too - I suspect the sun makes them brittle. I guess that's why they are selling replacements for $4 now. I ended up buying a new one and a backup.

My theory is the hook is so heavy it jumps off the chain from it's own inertia.
They should put lightning holes in it.