Input on Snubber Set-up

[Weatherbird]

I'm designing a general use snubber system for my boat.

The current plan consists of 20' of 1/2" three strand nylon with an eye splice in each end. Each end is connected with a 3/16" dyneema soft shackle – one to the chain (3/8" all chain rhode) and the other to a 3/8" clevis pin in my bobstay chain plate.

When not in use I would leave the chain plate end connected and pull the tail on deck.

My primary concern is the interface between the soft shackles and the three strand. I'd prefer not to use thimbles which could potentially strike the hull.

Is there anything I'm overlooking? Concerns and suggestions are welcome.

[CrispyCringle]

What size is your boat? If you have 3/8” chain, the 1/2” 3 strand seems small to me. With no other info, I’d think 5/8” or 3/4”.

[Shrew]

You going to anchor your entire rig on a 3/8" clevis pin on the bobstay to a 3/16" dyneema soft shackle, to a 1/2" spliced loop?

Start off by asking yourself.....why is NOBODY doing this?

Second ask yourself .......what you're gaining rather than just running the snubber up to your cleats?

Personally, I would not sleep well anchoring a 40 foot boat with this rig. spliced loops without thimbles are subject to friction. 1/2" is a small snubber IMHO. I don't trust the clevis pin to soft shackle to spliced loop.

IMHO I'd run the snubbers up to my cleats and be done with it.

What problem are you trying to solve here?

[Weatherbird]

@ChrispyCringle I should be somewhere between 1/2" and 5/8" but I have a different setup if I'm expecting a storm.

@Shrew Others are doing this. The weakest link is the three strand which is strong enough for almost all conditions. What I'm trying to solve is my snubber sawing on my bobstay and hawsehole.


I could go up to 5/8" and increase the shackle size to keep the strength proportional but having a larger diameter snubber doesn't help me if I don't need it. The goal of the snubber is to reduce the loads on the anchor. If I never exceed the safe load on the three strand then going up a size is counterproductive. (Although that might be what I do.)

Practical sailor recommended soft shackles 1/2 chain size for attaching a snubber which is what I've used here.

[Kettlewell]

Personally, I think 1/2" is plenty, and 3/8" would be fine for most conditions. Keep in mind that you want the snubber to absorb the shock loads and have plenty of give. If it is too heavy or too short it won't serve it's primary purpose. Second, I have used a 3/8" snubber on a 38-foot heavy motorsailor for many, many years and have only once had it break, but that was rather deliberate. I was curious to see what it would take, so I used the same snubber for many years, left it on the bow continuously, including the tropics, and finally it snapped in a 45-knot multi-day gale right in the middle. I suspect if I had been reasonable and replaced it every year or two nothing would have happened. However, 1/2" will probably be fine as long as you put enough out. I would want it longer. At least 25 feet, and maybe more. One problem with attaching it to the bobstay fitting is that you can't adjust it once deployed, which I have found useful. I installed a bow eye, like a towing eye, in the bow, just above the waterline, and used it for many years with the 3/8" snubber just attached with a spliced in eye looped through. The problem would be if I needed to let out scope in the middle of the night it meant I had to crank in a fair bit of chain and then reattach the snubber, then let the chain out. With a snubber cleated on deck you can either just let out more length, if the snubber is long enough, or just cast off the snubber and attach another one. I always just tied the snubber onto the chain with a modified rolling hitch and it never slipped or failed in decades of use. I have had to adjust my scope many times, often in the middle of the night when it starts to blow, and it is inconvenient to difficult to have the snubber permanently attached like that.

[stormalong]

Originally Posted by Shrew

You going to anchor your entire rig on a 3/8" clevis pin on the bobstay to a 3/16" dyneema soft shackle, to a 1/2" spliced loop?

Start off by asking yourself.....why is NOBODY doing this?

Second ask yourself .......what you're gaining rather than just running the snubber up to your cleats?

Personally, I would not sleep well anchoring a 40 foot boat with this rig. spliced loops without thimbles are subject to friction. 1/2" is a small snubber IMHO. I don't trust the clevis pin to soft shackle to spliced loop.

IMHO I'd run the snubbers up to my cleats and be done with it.

What problem are you trying to solve here?

My snubber is backed up by the anchor chain in a chain stopper with a sag in the chain. The nylon has broken a couple of times under extreme conditions and the chain held the boat.

Are you thinking that the chain would be detached while using the snubber? I have never seen a snubber used that way. The snubber is a shock absorber and chain noise suppressor, nothing more.


To the OP: I run the snubber line to a deck cleat and over the same anchor roller the chain goes over. Been doing it that way forever.

[SailingHarmonie]

The Clovis pin attachment is dicey, and can not be routinely inspected for chafe.

The snubber is too short. Longer is better. Why not 50 feet?

In an emergency where you need more scope or need to release the anchor entirely there is no way to release the snubber without pulling the chain in first.

Why not just tie a rolling hitch on the chain? Simple is good.

[GordMay]

You could run the [longer] snubber through an ‘eye’, at the bobstay attachment, and up to a deck cleat.
This would [both] lower the effective angle of the snubber, and allow easier attachment/detachment, and adjustment.

[GordMay]

Originally Posted by GordMay

You could run the [longer] snubber through an ‘eye’, at the bobstay attachment, and up to a deck cleat.
This would [both] lower the effective angle of the snubber, and allow easier attachment/detachment, and adjustment.

Where you're using the eye 'like' a turning block.

[Weatherbird]

Thank you for all of the feedback. I've thought about everything that was said and think I have a plan addressing most of it.

Note: Beyond moving the chafe point around, I don't see a major benefit in adjusting the snubber length so I'm only going to worry about releasing it in an emergency.

There are a number of ways to route a dyneema lead attached to the three strand (or the three strand alone) from the deck either directly around the clevis pin, through an attached low friction ring, or straight to the chain. All of them result in a line wearing on the hull or bobstay. I checked.

If I stick with the original idea, but create a reliable way to cut the soft shackle attached at the hull then I've addressed the rare worst cases of abandoning the anchor or of needing to increase scope but being unable to get the chain in.

I think a line cutter (like the one pictured) zip tied to the boat hook would be effective at cutting the soft shackle at the hull.

So, the new plan is as before but with 30' of 5/8" three strand, 1/4" soft shackles, three zip ties, and a line cutter.

[Dockhead]

30' of 5/8 is a light weather snubber. You should have several of them of different sizes and lengths for different weather. For strong weather you want to choose nylon rope at least as strong as your chain (remember nylon loses strength when wet and when under cyclical loads) and then long enough to give you the elasticity you need. G4 chain has breaking load of 16,000 pounds. In really strong weather you will want to rig two snubbers, so I would have a couple of your heavy weather ones.

You don't need to necessarily make off the snubber at the bobstay chainplate. You can rig a block there and lead a line up over a spare anchor roller and then you've got control over it, and no need to cut it in an emergency. Dyneema is good for this because of chafe but slippery for putting on cleats, so I would use a strong piece of polyester. Chafe will be minimal if it's coming through a block and then over a bow roller.

I agree with others about the clevis pin -- you will want some kind of stronger fixing there.


You've got a chain stopper, or some other way to belay the chain, right? Don't use the snubber for this.