Rolling Hitch on Snubber

[estarzinger]

We have at various times discussed ways to attach snubbers to chain. I had pretty much always previously used a chain hook, but based on some discussion here I decided to try the very simply rolling hitch method.

I will say that it is a bit easier and less clumsy than using a chain hook.

But I had the below happen last night:



This is Dacron double braid in relatively good condition. The winds were about 30 with gusts to 35kts with some decent chop - not terrific but also not horrible.

It looks to me like the line cut itself in half, where the loaded portion comes out from under one of the 'half hitches'. There are various ways to tie a rolling hitch (And note that I used three wraps on the loaded side of the hitch rather than the more typical two), and we can debate that, but #1 note the knot itself did not slip or fail, and #2 all the various ways to tie a rolling hitch (I think) have the loaded portion bearing on a 'locking half hitch' in this way.

I had tried to experiment with a spectra tail on this line, and tie the rolling hitch in the spectra, because I actually had thought the likely failure point would be the line chafing on the chain, but I did not find a method I really liked, and while spectra is much more resistant to chafe, it is vulnerable to this sort of tight radius 'cutting itself'.

Anyway . . . . thoughts or suggestions. For today I have gone back to chain hooks.

[skipmac]

I used a Prussic knot and three strand on my snubber and had no problem with chafe. The worst conditions on my last cruise with that setup were similar, occasional gusts to >30 kts, with a moderate chop. No evidence of chafe at all on the snubber the next am. I like the three strand for the extra spring effect as well.

By the way, this was on 25 year old, fairly rough chain so ample opportunity for chafe.

[colemj]

In previous threads, didn't you introduce the icicle hitch? Would that load on the chain differently than a rolling hitch?

BTW, what do you find clumsy about a chain hook?

Mark

[Thumbs Up]

I always use a loop of heavy webbing, prussik knot, then sheet bend onto my bridle loop. Works over rope or chain and is easy to untie.

[model 10]

Using double braid for something like this is a little sketchy. A good portion of the strength is in the cover and it's pretty thin.

[David M]

The nautical term for a chain hook is a devils claw. They will never chafe or get so tight you have to cut it off. There is also the option of a pelican hook which can be released under a load. A pelican hook will also not shake off if there is no load like a devils claw could.

Devils claw


Pelican hook

[Kettlewell]

In your photo it looks like the line passes through a link in the chain, but maybe I am misinterpreting the image. I actually tie something more like what this one site calls a "safety belt hitch" but I actually take a bunch of turns around the chain before securing it with a couple of half hitches. I've never had the line chafe like that in even severe conditions. I use nylon three strand for the snubber.

[model 10]

If you could find a galvinized Devils Claw that would be great but the plain steel job turns pretty ugly.

[David M]

I would imagine you could get one in stainless, find a galvanized one or go get one galvanized. But yeah, it would be a ball of rust pretty quickly otherwise.

[colemj]

Originally Posted by Kettlewell

In your photo it looks like the line passes through a link in the chain, but maybe I am misinterpreting the image.

I think that is where the standing end of the line parted - the parted end is just resting there afterward.

Isn't your picture a rolling hitch? What's the difference?

Mark

[model 10]

David: I looked pretty hard for one that does not rust, no luck. On an aside, the Devils Claw is the only way of having a hook that does not put an improper strain on the chain. There were some cheesy hooks made from 1/4-5/16 wire in stainless but I think they were a joke. All these other jobs put a bending load on the chain.

[skipmac]

Originally Posted by colemj

In previous threads, didn't you introduce the icicle hitch? Would that load on the chain differently than a rolling hitch?

BTW, what do you find clumsy about a chain hook?

Mark

Since I've never used a chain hook I'm merely guessing but seems to me that handling a chain hook, claw or whatever similar device would be much more awkward than line.

With a line tied to the chain I can winch the knot over the bow roller and even the gypsy if need so it is at close hand to untie, lengthen or whatever. Would you not have to unhook a claw before the roller so you're leaning over the bow with a boat hook or something?

[foolishsailor]

Originally Posted by Thumbs Up

I always use a loop of heavy webbing, prussik knot, then sheet bend onto my bridle loop. Works over rope or chain and is easy to untie.

+1

Thinking about changing to a loop of heavy dynema as it is very wear resistant.

[valhalla360]

We make a simple bridal with a long dock line and a pruissic in the middle with each end going to a different bow.

It works on chain or rope rode. Never has slipped or chaffed.

A chain hook seems like an extra item to keep track of.

[estarzinger]

Originally Posted by skipmac

With a line tied to the chain I can winch the knot over the bow roller and even the gypsy if need so it is at close hand to untie, lengthen or whatever. Would you not have to unhook a claw before the roller so you're leaning over the bow with a boat hook or something?

Exactly. Also most designs of chain hooks can slip off (a very few have 'keepers' built into the design but those tend to be fiddly if you have to lean over the pulpit to engage/disengage them)- there are tricks and techniques to avoid that but it is an added 'clumsiness'.

As to other knots . . . previously this summer I was trying a klemheist hitch around the chain with a spectra loop, and a sheets bend to attach this loop to the Dacron snubber line. This is very similar to the pruisk (I thought just a little bit better for the snubber application). But I found untying the sheets bend a bit of a pain, especially after it had been loaded up for several days. So that's when/why I started giving the rolling hitch a try, because I thought it would be quicker/easier to tie and untie.

The icicle hitch and some others have greater grip, but they are more complex to tie (I at least can't do them from memory) and grip does not seem to be the problem here. The rolling hitch gripped just fine.

Also most of these knots/hitches seem to have the same structural feature that cause my line to cut itself (note it was not chafe on the chain, but the line cutting itself). In the picture below I have circled in black where I think it rubbed/cut itself, and pretty much all these 'gripper knots' have a similar 'loaded part under a loop'.



I m not condemning any of these options. I have been experimenting with various approaches to try to find the best. The rolling hitch has (so far) been by far the easiest. But I was just very surprised by this failure last night. . . .not sure what to make of it.