Rolling Hitch on Snubber

[s/v Jedi]

Originally Posted by foolishsailor

+1

I use them for many things. Never thought to use them to tie a snubber. Only concern I would have is during slack lack of tension time, would it work itself loose? Sometime on our racing head sail we find the dyneema soft shackles work loose. Unusual, but not unheard of.

A good soft shackle can't work loose. If you have that, then the loop is too big. Here you can see the maximum openingfor this one; also check how it prevents opening any further. I have decided on this design for the shackles aboard Jedi after making three different popular versions.

[transmitterdan]

Originally Posted by s/v Jedi

Oh my, I'm afraid you got some things backwards... it is your snubber that is too big at 1/2". Mine is 5/8" which is only 1/8" more while my boat weighs 4 times yours I guess... Also, the climbers rope is designed to stretch while 3-strand does so because they couldn't make it better. Next it the length of your snubbers which is just way off. 125', really?? that means it will stretch to 250', you don't even have that much extra chain to spare, reducing it's usefulness.

99% of the time we use a 25 foot snubber. Just to clarify, the backup snubber is 75' and it is only a backup to the heavy weather 50' snubber. I did not advocate a 125 foot snubber but maybe that was somehow implied. We hitch the backup to the chain a couple of feet behind the primary. If the primary stretches 25 feet then the backup begins to take some of the load up to the point where the primary fails but this has never happened. I can be convinced to go to 3/8" but 1/2" has been working quite well.

It's not all about displacement but also about wind loading but your point is well taken.

[noelex 77]

Originally Posted by s/v Jedi

A good soft shackle can't work loose.

I think a soft shackle would work well, but I cannot see any advantage over a conventional shackle for this application.

It would be so cool to use something beautiful like this, but if I could this sort of work, I don't want it at the end of the snubber.

Before I can tackle this sort of perfection I guess I need to learn how to tie rolling hitch that won't slip

[Mantus Anchors]

Originally Posted by colemj

What is the caribiner for?

Mark

Mark the carabiner is there attach the bridle to a mooring loop, so if you come up to a mooring instead of the hook, will have a carabiner on the bridle and you just clip to the mooring loop....
This way you do not have to bring the dirty mooring line on board...
The idea came from one of the cruisers on here.... that has his boat in BVI and that's what folks do over there, but they are paying crazy money for the carabiners big enough to take the 1 inch line used on moorings..
Greg

[Mantus Anchors]

Originally Posted by s/v Jedi

Instead of shackles or caribiners, you should use a soft shackle.

The reason we went with the hook and shackles and thimbles...:

We used three stand line to have maximum stretch for length
We used the metal hardware to insure protection from chafe...
Line working load is 1/12 - 1/15 of Ultimate breaking strength bc line wears in an unpredictable way. Thus we wanted to offer as much protection to the line as possible...
I.E Heavy duty nylon sleeve, stainless steel thimble with a nice radius and Mantus Hook which is rated to be as strong as the Hi test chain.... its used with, so in all we wanted the system to be wear proof, storm proof...... and easy to use....
Greg

[Cotemar]

Here is my 5/8" dia. three strand Snubber Bridal. Each leg is 20 feet long. The rubber snubbers should prevent high snatch loads since they stretch to twice their length along with the three strand bridal stretch. Used all figure 8 knots for strength.

I have been using a Winchard Key Shackle 5/16” on my bridal for 4 years now
It is connected through my 5/16 High Tensile G4 chain. Has never disconnected and it is simple and fast to use. I have been looking for something a little beefier that locks as our bridal lays on the sea bottom most of the time in shallow anchorages.

[foolishsailor]

Originally Posted by s/v Jedi

A good soft shackle can't work loose.

I guess i dont believe in absolutes as what you said is not the case in practice. However, the security of a shoft shackle dramktically increases with the diameter of the line used.

[estarzinger]

For the spectra loop crowd . . . here is a solution that seems to meet all my criteria:

I made up a very long soft shackle. Wrap it around the chain in any of the possible hitches (this is the klemheist) and then join the soft shackle thru a thimble in the snubber line. The thimble is there to increase the bend radius and make it 'smoother' - not sure if its actually needed.



Here is the soft shackle 'undone' . . . this will never jam under load and always be pretty quick to undo (unlike the sheet bend or other knots).



Then it struck me there might be an even 'simpler' way to use the soft shackle - thru the chain link, which will obviously never slip and with the spectra I don't think it would chafe. You could take the loop twice thru the chain if you wanted to minimize chafe potential further, but I am guessing it is not necessary and adds a step.



This is all independent of the debate about what sort of line to use behind the soft shackle - it could be any type.

Originally Posted by Dockhead

Does any reasonable person use polyester for an anchor snubber? Same answer.

mmmmm . . . .does any reasonable person use Dacron for a mooring pennant? . . . . yes, essentially anyone who has studied the situation.

I am afraid you and I will not agree on this . . . that's fine with me.

You directly imply that I am not a reasonable person . . . . that's fine with me also . . . but a bit odd for a mod I think.

[noelex 77]

Originally Posted by Cotemar

The rubber snubbers should prevent snatch high loads since they stretch to twice their length along with the three strand bridal stretch.

The rubber snubbers (or the more expensive ss springs)seem like a good solution.
There are a lot of advantages to a short snubber that has a lot of stretch,but I have been told that the rubber stretch snubbers unfortunately do not last. A few days at 40-45k
Seems to be the consensus.
Cats have lot of advantages in spreading the load with snubbers but I am interested in the experience of others especially in monohulls.
Do they last?

[Andrew Troup]

Dockhead

I'm glad you've withdrawn one of your accusations about the broken snubber.

As to the other: every material has elasticity. You may be speaking shorthand when you claim that polyester rope does not, but I think it's potentially misleading. Even straight chain has elasticity.

Dacron (polyester) halyards are a lot more elastic than wire halyards, but even wire halyards stretch.

There are situations where a polyester rope's degree of elasticity would render it perfectly suitable for snubbing.

In some cases nylon is just too elastic. One problem with this has been touched on further up the thread: the heat buildup is too concentrated (a polyester snubber for a given situation is a lot longer, so it dissipates a given amount of energy without the same temperature rise). This largely explains why the dynamic climbing ropes of which you speak must be discarded after a VERY low number of load cycles. (ie, falls). Nylon does the job, but at a cost to itself.

The crucial point, I reckon: for any snubber not to be at risk: the elongation should be controlled by the amount the chain is eased. The chain should straighten before the snubber reaches a % elongation corresponding to a load which will, over time, cause it to fail.

It seems to me that, regardless of material, that failure load limit will need to be set lower if the snubber terminates in a rolling hitch than a sheet bend, because in a decent bend, the rope receives some clamping to get rid of tensile stress before it is required to perform a sharp turn.

I think that to dismiss a potential learning opportunity in the OP, albeit "learning by proxy", would be a shame.

Maybe I'm unfairly maligning rolling hitches and I may be maligning nylon. In the latter case, I think it's partly because I favour much heavier chain than is currently fashionable, so there's little extra energy left to 'sop up' by the time that's been hauled straight.

In fact for me, except in the most extreme conditions, or on a boat whose chain is light in relation to displacement, a snubber is a short affair rigged with minimal 'give', intended to keep the noise of chain rumble from telegraphing through the bow roller more than anything else. And pretty much any type of line will serve.

I realise that, in theory, heavy chain is a total waste of time, but I console myself with how well it works in practice.

[Andrew Troup]

Originally Posted by Dockhead

Over 90 degrees is not a sharp bend inside a knot. The humble rolling hitch is actually one of the strongest knots in existence (if not the most secure) because the angles are quite mild compared to most other knots. I've never seen a failure of a nylon snubber at the knot -- they usually break where they're led over the rail or through the anchor roller, or in the middle.

No knot which is capable of securing a rope to a chain and pulling it in the same direction will have an initial bend of less then 90 degrees -- by definition. If you're worried about this, then Andrew Troup's strap is the way to go (but recognizing that his strap also bends at more than 90 degrees ).

I'm not visualizing how a sheet bend -- or any bend -- could be used to attach rope to chain, unless you are making a loop in the chain. The sheet bend is one of my favorites in my pretty limited repertoire of knots, because of its extreme convenience, but I am conscious that it is neither strong nor secure. The best is the double fisherman's bend, which is apparently the world's strongest bend. This from a fascinating practical test of different knots in PBO recently.

Sure my strap bends at more than 90 degrees .... well spotted.

.... but this is not a problem for webbing, because the outermost fibre is so close to the innermost fibre on a tight bend. It's one of two reasons why webbing slings replaced rope slings in industry as soon as suitable looms became widely available, a lifetime ago for many ...

A sheet bend can be used to attach rope to the sling: the sling forms the standing part of the bend. (double sheet bend is preferable, especially when time comes to untie)

You say you are "conscious that it (sheet bend) is neither strong nor secure"

In that case, I presume you feel similarly cagey about a bowline? It's the identical structure.

[s/v Jedi]

Originally Posted by estarzinger

For the spectra loop crowd . . . here is a solution that seems to meet all my criteria:

I made up a very long soft shackle. Wrap it around the chain in any of the possible hitches (this is the klemheist) and then join the soft shackle thru a thimble in the snubber line. The thimble is there to increase the bend radius and make it 'smoother' - not sure if its actually needed.

Here is the soft shackle 'undone' . . . this will never jam under load and always be pretty quick to undo (unlike the sheet bend or other knots).

Then it struck me there might be an even 'simpler' way to use the soft shackle - thru the chain link, which will obviously never slip and with the spectra I don't think it would chafe. You could take the loop twice thru the chain if you wanted to minimize chafe potential further, but I am guessing it is not necessary and adds a step.

This is all independent of the debate about what sort of line to use behind the soft shackle - it could be any type.

mmmmm . . . .does any reasonable person use Dacron for a mooring pennant? . . . . yes, essentially anyone who has studied the situation.

I am afraid you and I will not agree on this . . . that's fine with me.

You directly imply that I am not a reasonable person . . . . that's fine with me also . . . but a bit odd for a mod I think.

You nailed it Evans, this is the best system. The only improvement I can think of is changing the soft shackle to the "improved soft shackle" design I showed in my pictures, which prevents the loop opening further than needed. If you Google for the string I quoted previous sentence, you will find a calculator to get it exactly right.

I believe nobody realizes you just posted the ultimate solution they will probably ignore it because it can't be ordered on-line lol

[SVNeko]

Originally Posted by s/v Jedi

You nailed it Evans, this is the best system.

Which one? He posted two.

[s/v Jedi]

Originally Posted by SVNeko

Which one? He posted two.

The one with the green colored soft shackle, regardless of how you attach it to the chain.

[Cotemar]

Originally Posted by s/v Jedi

You nailed it Evans, this is the best system. The only improvement I can think of is changing the soft shackle to the "improved soft shackle" design I showed in my pictures, which prevents the loop opening further than needed. If you Google for the string I quoted previous sentence, you will find a calculator to get it exactly right.

I believe nobody realizes you just posted the ultimate solution they will probably ignore it because it can't be ordered on-line lol

I think we all get it, but do not have all the info to make it.
Can you show us the way all mighty Jedi