Rolling Hitch on Snubber

[Singleprop]

Originally Posted by Delfin

A stunning amount of knowledge and information can be derived from this thread, so thank you, all contributors.

My humble contribution is in the area of chafe protection. Having tried everything you can think of, I found that leather usually described as "Harley" leather that can be purchased from Tandy Leather in Seattle, and shipped anywhere in the world is the ultimate. It is around 1/8 - 3/16 thick and cured black, like saddle bags. The color of the leather is fast - I've never seen any bleeding. I bought about half a cow's worth and have found a great many uses for it, not the least of which is line chafe gear. I purchased a leather punch from a hobby shop and use that to pre-drill stitching holes 1/4" apart. I use line whipping for the stitching.

After 3 years usage, the chafing protection I sewed onto my mooring lines are essentially unaffected by usage. I finally used a leather cream on them as they were starting to lose color and they basically look like new. After three years!

The technique is to cut the leather about 1/4" under the diameter of the line. I use a razor knife. Then, when stitching, the leather should be so tight that the lay of the strands should be visible. this ensures the leather won't creep out of place with usage. I'm using 3 strand nylon for dock lines.

I have also used the same material to sew onto the rails of the Boston Whaler tender so they don't ding the paint when tied alongside Delfin, as well as to wrap the steel drum of the Pullmaster winches so the cable won't chafe the painted drum, as well as various areas where one thing bumps up against another.

Really, this kind of thick leather, properly applied is to any other method of providing chafing protection what Boudeaux is to Kool-Aid. I'll try to post some pictures if anyone is interested.

Thanks again for all the knowledge transmission here - much appreciated!

Always interested in good solutions, please post some pics..

[Nor'Sea 27]

Yes - if possible include your list of sewing tools and the twine you use. Maybe even consider new thread?

Charles

[s/v Jedi]

Originally Posted by Singleprop

Always interested in good solutions, please post some pics..

Just a quick Google image search:

[model 10]

I think a Baseball stich is more appropriate for this.

[Delfin]

Originally Posted by s/v Jedi

Just a quick Google image search:

Not so much.

I'll take some pictures and post them.

[Dockhead]

I've made a new thread on dynamic loads on snubbers and choice of material, inspired by the good discussion in this thread: http://www.cruisersforum.com/forums/...ml#post1246745

I hope some of the engineers among us will improve this work.

[Mantus Anchors]

I think your illustration why shock absorption is important is very vivid...
When we size our bridles, we use three strand nylon line such that when in 40 knot winds you will steel have enough stretch, elasticity to stretch another 3 feet, i.e 8
% with shock loads from gusts or a waves.
Three strand has 8% stretch when the load is 10% of ultimate breaking strength and is 16% stretch when load is 30% of ultimate breaking strength.
So if we have a 35 foot boat in 42 knot storm the expected load on the bridle is 1800 lbs (ABYC table) which is the working load for our 5/8 (line diameter) bridle.... which is 1/12 of the UBS.
with a gust or a wave strike the shock loads could be double or triple the baseline load and we want our bridle to accommodate this spike loads.
So we chose to size so that bridle will be at working load in a 40 knot storm.....

[Mantus Anchors]

We just finished coming up the ICW and after many, many nights of anchoring I had tried all kinds of different ways to connect the chain to the bridle. I tried hooks, shackles, rolling hitches, etc. All had their shortcomings. Took too long to install / remove, fell off, etc. Then I found the Mantus chain hook. What a beauty in simplicity! Easy to install on the chain and easy to remove. Literally only takes seconds. The Mantus hook never fell off, even when it lay in mud all night. I could not be happier with this purchase. If you're looking for the perfect chain hook, check out the Mantus.

New Product From Mantus Anchors! - Multihulls4us Forums
__________________

[Bash]

Originally Posted by thinwater

No. And this distinction is important because dynamic rope does not behave like double braid.

Not all kernmantle is dynamic. Indeed, Kernmantle was around before dynamic ropes were developed.

[JonJo]

There is a tendency for it to be stated that people use climbing rope for a snubber, when as Bash comments Kermantle is not exclusive to climbing ropes and there are also different types of climbing ropes, Dynamic and Static being one distinction. There are also different sizes of climbing ropes and I'd guess an 8mm dynamic will be very different to an 11mm dynamic which is very different again to a static 10mm. Climbing ropes can also treated for water resistance, though I do not know how long this might last in a marine environment.

Interestingly - no-one has yet mentioned their climbing rope snubber has failed (even though some are using 'second hand' rope - but maybe there are not enough users for this to be statistically relevant.

Jonathan

[Kettlewell]

Interestingly - no-one has yet mentioned their climbing rope snubber has failed (even though some are using 'second hand' rope - but maybe there are not enough users for this to be statistically relevant.

I've never had 3-strand nylon marine rope fail either, and many times I have used rope of unknown provenance and age. I believe that anchor loads are way lower than many authoritative sources indicate.

[Delfin]

Originally Posted by Singleprop

Always interested in good solutions, please post some pics..

Low tech, but these leather wraps seem to have solved the chafing problems for me. The key is to cut the leather a bit shy of the diameter of the line - about 5/16" - so that when you pull really tightly on the stitching the gap closes and the leather is so tight you can see the strands of the line. This prevents it from moving and may even help reduce internal friction heat during cyclic loading since the fibers seem packed almost too tight to move. These have been through three seasons and show zero signs of wear on the leather, although they will probably have to be re-stitched.

Also shown is leathers sewn onto the rail of the Whaler, the tools as requested, and a couple of shots of the leather used. As noted above, if you can find this 'Harley' leather, it seems almost bullet proof.

[Cotemar]

Originally Posted by JonJo

There is a tendency for it to be stated that people use climbing rope for a snubber, when as Bash comments Kermantle is not exclusive to climbing ropes and there are also different types of climbing ropes, Dynamic and Static being one distinction. There are also different sizes of climbing ropes and I'd guess an 8mm dynamic will be very different to an 11mm dynamic which is very different again to a static 10mm. Climbing ropes can also treated for water resistance, though I do not know how long this might last in a marine environment.

Interestingly - no-one has yet mentioned their climbing rope snubber has failed (even though some are using 'second hand' rope - but maybe there are not enough users for this to be statistically relevant.

Jonathan

Not many are using climbing rope as a snubber. Climbing rope is designed to be used by 300lb climbers not a 10,000 catamaran.

If someone gives you climbing rope because it’s not usable for a 300lb climber, why would you ever think it would be a good idea to use it on a 10,000 catamaran snubber.

3 strand nylon line, 8-Strand Plaited & Double Braid Nylon Line have proven themselves in the marine environment for years to secure 10,000 lbs. catamarans to 100,000,000 lbs. ships.

You’re charting your own course using climbing rope as a snubber and best wishes to you in your journey. Hopefully you will not have many followers as that Kool aid may get sour.

[svmariane]

Originally Posted by s/v Jedi

Can't say I recognize the practices that I though everybody followed...

1. The rope attaching the bitter end of the chain to a strong point aboard should be long enough so that it appears on deck, between windlass and anchor roller, so that it can be cut right there if needed.

2. If anchor must be slipped in a hurry, there is no unhooking the snubber; no using the windlass to release tension. There is just taking the snubber off the cleat and releasing the windlass clutch. This is why the bitter end of the snubber should not be a spliced loop.

Agreed.

We know that the snubber might break sometime, as that's the way of things.

For that scenario: I've a second snubber with chain hook, attached to the anchor chain just outside the bow roller, and cleated off to the unloaded bow cleat. {I use a short chunk of thin line to help keep the hook in place.} That second snubber would take the strain should the first one break. Too short for long usage - agreed - but it'll be something stretchy holding the chain vs just my windless, giving me a bit of time after that loud BANG to get forward and sort things out. That 2nd snubber is a one-to-one replacement for the 1st, and can be let out as needed.

Belt and suspenders, maybe... But what the heck.

[svmariane]

And apologies for talking about chain hooks when the OP wanted help with a Rolling Hitch problem.