Snubber sizing for All Chain Ground Tackle

[Paul L]

Originally Posted by Mike OReilly

I don’t know much about carabiners, but any I’ve seen that would fit through a typical chain link used on cruising boats would have to be fairly small. I would bet its load limit would be below the chain load limit, but perhaps I’m wrong?

I have heard about people using soft shackles to attach snubbers to chain. This Dyneema-type line can be stronger than most chain. Not sure about chafe though…?

To me, a rolling hitch is the simplest, and most secure way, I’ve found to attach my snubbers. Every hook I tried had some sort of failing. The only problem I’ve had with rolling hitches is when I’ve set them too long in shallow anchorages and they’ve rubbed loose when coming into contact with the bottom.

I've been using a soft shackle to attach the snubber for about 2 1/2 years now. I think it is a superior method over hooks and hitches. Simple to attach and detach. I broke a 5/8 snubber while using a soft shackle and the shackle showed no obvious damage.

[Simi 60]

How does the soft shackle attach?
Loop through link and then hard shackle through soft onto thimble of snubber?

That's not simple so I am guessing there is an easier tool free way.

[Paul L]

Originally Posted by Simi 60

How does the soft shackle attach?
Loop through link and then hard shackle through soft onto thimble of snubber?

That's not simple so I am guessing there is an easier tool free way.

The loop end of the soft shackle goes through the chain link and then through the eye of the snubber. Then the knot end of the soft shackle goes through the loop end. No hard shackle, no tool.

[evm1024]

Mantus uses 22' long 5/8" dia on each leg for their small bridle. Speced for boats 30' to 40' without a displacement noted.

The medium is 25' of 3/4" per leg (40-50').

The Large is 30' of 1" per leg (50-70').

Take a look at their catalog for ideas.

Also, Mantus sells snubber pendants made from UHMWPE that can be used to connect to the chain. Prusik to the chain in the smaller size and girth hitch in the larger sizes. These pendents include significant chafe protection.

[Simi 60]

Originally Posted by Paul L

The loop end of the soft shackle goes through the chain link and then through the eye of the snubber. Then the knot end of the soft shackle goes through the loop end. No hard shackle, no tool.

Fair enough and it obviously works.
It sounds dodgy as its only gravity and tension keeping it together, but the same can be said of a hook.

Being a loose item I'd be worried about "passion fingers" dropping the soft shackle over the side. Many spares would be required.

One obvious benefit with our hook is it drops off when it touches the roller meaning I can pull the anchor single handed from the wheelhouse if need be, no need to send the crew on deck if weather is ordinary. Snubber with hook attached can drag, pressure wave keeps it off the hull.

[Jim Cate]

Originally Posted by evm1024

Mantus uses 22' long 5/8" dia on each leg for their small bridle. Speced for boats 30' to 40' without a displacement noted.

The medium is 25' of 3/4" per leg (40-50').

The Large is 30' of 1" per leg (50-70').

Take a look at their catalog for ideas.

Also, Mantus sells snubber pendants made from UHMWPE that can be used to connect to the chain. Prusik to the chain in the smaller size and girth hitch in the larger sizes. These pendents include significant chafe protection.

I'm having a hard time understanding why one would attach a snubber to a rope rode. The Mantus pic looks quite tidy, but whhyyyy??

Jim

[wrwakefield]

Originally Posted by CaptainDana

...
I'm trying to trigger the armchair experts...

I'm not sure you would consider me qualified to answer as we don't have any armchairs on our boat...

I won't evaluate your set-up as we all have different needs and experiences, and the needs can change with season and location...

If you want to evaluate your methods using an engineering approach, [highly recommended] Thinwater has performed the most recent work I'm aware of, and documented it well in Practical Sailor and with more details in his Rigging Modern Anchors book.

Our approach is similar after continual [and ongoing] refinement over the years.

Best wishes with your quest.

Cheers! Bill

[Paul L]

Originally Posted by Simi 60

Fair enough and it obviously works.
It sounds dodgy as its only gravity and tension keeping it together, but the same can be said of a hook.

Being a loose item I'd be worried about "passion fingers" dropping the soft shackle over the side. Many spares would be required.

One obvious benefit with our hook is it drops off when it touches the roller meaning I can pull the anchor single handed from the wheelhouse if need be, no need to send the crew on deck if weather is ordinary. Snubber with hook attached can drag, pressure wave keeps it off the hull.

Properly built soft shackles do not come a part by themselves. I use them in many places on the boat including connecting sheets to the staysail. These get flogged around and never come loose.
Once you've made a few soft shackles it is really easy to do a dozen at a time at maybe a cost of 1 or 2 dollars per shackle. So go ahead and drop them over board. By the way they do float.

Easy drop off of the hook in your set up is nice - assuming that it always drops when you expect it to and doesn't drop off when you don't want it to.

[Paul L]

Originally Posted by Jim Cate

I'm having a hard time understanding why one would attach a snubber to a rope rode. The Mantus pic looks quite tidy, but whhyyyy??

Jim

Perhaps to create a bridle?.......

[evm1024]

Originally Posted by Jim Cate

I'm having a hard time understanding why one would attach a snubber to a rope rode. The Mantus pic looks quite tidy, but whhyyyy??

Jim

You know that struck me too but only after I snagged the photo off the net.

I'm going to guess that it is on a rope rode because it is a bridle as well as a snubber.

Prusik it to your rope rode and then run the legs to each side of the boat.

[Simi 60]

Originally Posted by Paul L

Easy drop off of the hook in your set up is nice - assuming that it always drops when you expect it to and doesn't drop off when you don't want it to.

Early days it did on occasion but now we run out 12 ft or so of chain hanging in a loop and have been 700+ days/nights without a recurrence .

[GB32]

Sorry guys. I don't get it!
I've read through the posts and the sizes of nylon and the loads/stretch that are mentioned horrify me.
If you see Nylon part without a dramatic result it must be chafe that has weakened it to the point of not much load because parting Nylon under full load is damaging for people and equipment.

In general, Nylon, in good condition with little chafe, will stretch 30% before breaking and with the loads and the amount of stretch that is mentioned the recoil would be life-changing for anyone who gets in the way. The idea of a long length of nylon run to stern cleats across open decks and presumably people, is horrifying. The recoil would be bone breaking or worse.

I use 18mm or 3/4" braided Nylon with a chain hook onto all chain (10mm) on a 43ft Trawler.
When I set the anchor and test using the snubber I see the nylon stretch and the chain category rise accordingly. I don't get close to the breaking point but still clear the deck incase of a breakage.
To me there are 3 reasons to use a Snubber:
1. To take the load off the windlass, gypsy and chain stopper.
2. To keep the noise and wear down if yawing while on anchor
3. Allows me to see the stretch and assess how much load is being taken - useful when testing the Anchor - but stretch once anchored tells me 'time to go'.

In no way do I want much stretch - not even 10% of the breaking load. I rely on the catenary of the chain to do the dampening. If the Nylon is working hard that tells me I don't have enough dampening from the chain catenary and pay out more. The idea of melting nylon tells me to use bigger diameter - not live with the risk of parting.
In commercial marine operation Nylon is not used except for specialist applications - the reason, it's too damned dangerous. Please be aware of how dangerous the recoil of even small diameter Nylon can be.
I have no experience of chain/rode systems and claim no expertise except 40 years working on ships and at sea.

[wrwakefield]

Originally Posted by Jim Cate

I'm having a hard time understanding why one would attach a snubber to a rope rode...

Jim,

In the days I used rope rode, I would use a snubber [or bridle] in inclement conditions to transfer any possible chafe points [under load] to the snubber with the intent of sparing the rode.

I can't quantify if it was worthwhile or not as I never was successful ruining a snubber due to good chafe protection...

FWIW

Cheers! Bill

[ebsail]

Dont see any problem using the long snubber other than trying to find a route the length of the boat where the nylon line does'nt chafe on anything. With 2' of stretch overall, it can't touch anything without a very good chafe guard that will keep the line cool and not let it abraid.

[Mike OReilly]

Originally Posted by Paul L

I've been using a soft shackle to attach the snubber for about 2 1/2 years now. I think it is a superior method over hooks and hitches. Simple to attach and detach. I broke a 5/8 snubber while using a soft shackle and the shackle showed no obvious damage.

Thanks Paul. I may give the soft shackle a try.