Confused about snubbers

[and4ew]

I've been reading about snubbers and am now confused. I see them sometimes described as approx 30' of 3-ply nylon attached to anchor chain. Then I see pictures of these rubber things with rode spiraled through them. First question: are both these things "snubbers"?

I do understand that the purpose of a snubber into reduce shock loads. Second question: But if my anchor chain is attached to anchor rope and then to my boat doesn't the rope act as a snubber?

Note I don't have a windlass I usually just cleat the rope.

[Dsanduril]

They’re all “snubbers”. With an all-chain rode you want something with a little elasticity. A length of nylon attached to the chain and the boat can do that, but if you look at the math you need a pretty fair length (5-10m) to be really effective.

You can reduce that length by using one of the rubber or spring devices. That just introduces additional “stretch” where you don’t have room for the length (they frequently get used on dock lines).

If your anchor rode already includes line then you probably don’t need anything, although it does depend a bit on the line you have.

[Mike OReilly]

What Dsanduril said .

Those rubbery bands allow the distances to be shorter by wrapping the line around the device. But it's unclear to me how much total line length you actually save since it's wrapped around the rubber band. I've never used one, but I bet you don't really reduce your total snubber or dockline length all that much.

Personally, I don't see the benefit of these things for snubbers. I see the utility for dock lines where distances between dock and deck cleats may be too short, but it seems an unnecessary complication in the case of snubbers.

And yes, if your boat uses a chain/rope rode, and you anchor with all the chain down leaving a decent length of the rope as the attachment point, then you don't need an additional snubber line. The nylon rode will be sufficient most of the time.

[carstenb]

A good snubber reduces shock in both directions.
1- It takes the load off your windlass (which you don't have so this is not a worry for you), preventing the constant pulle and shock load from ruining your bearings on teh windlass.

2- It also reduces the shock loads on the anchor, helping ot ensure that your anchor doesn't drag.

A good snubber should be 4 ply nylon of a suitable size (1-1 1/2 inch is good for most boats) and Looooooong - 4-5 meters. It should also be a bridle to distribute the loads across two cleats and help maintain the anchor in front of the boat.

A very knowledgeable fellow once told me that if you spend the extra 5 minutes each time you anchor to anchor properly and anchor like you are expecting storm conditions - then you can sleep soundly at night. We've been on the hook almost 1000 nights over the past 4 years - and we sleep very soundly

[Chotu]

I had reasoned that the rubber shock absorbers would make a good addition to my snubber/bridle system. I was using them with 3/4" rope and they actually snapped apart in just a few weeks.

I don't think they're up to the task.

[Kelkara]

Originally Posted by Chotu

I had reasoned that the rubber shock absorbers would make a good addition to my snubber/bridle system. I was using them with 3/4" rope and they actually snapped apart in just a few weeks.

I don't think they're up to the task.

I expect it depends on both the boat and the rubber thing. I've been using one on my 27ft 5ton boat quite satisfactorily, even in winds of 40kts. I expect it will break some day, but so far it's lasted me three years (plus however long the previous owner used it).

[Mike OReilly]

Originally Posted by Kelkara

I expect it depends on both the boat and the rubber thing. I've been using one on my 27ft 5ton boat quite satisfactorily, even in winds of 40kts. I expect it will break some day, but so far it's lasted me three years (plus however long the previous owner used it).

Good to hear from a user of the system. What benefit do you gain from them as snubbers Kelkara? Like I said, the only real difference I can see is that they allow for a shorter length of snubber. But since you're wrapping the line around this thing anyway, I doubt you're actually using much less line.

They're not stronger than the line used, and it's not like they're superior to taking shock loads compared to decent quality nylon lines. I can certainly see the benefit for docking, and they might even make sense as a mooring snubber where boats are packed very tight, but I don't get the use in the case of anchoring.

[Kelkara]

Originally Posted by Mike OReilly

Good to hear from a user of the system. What benefit do you gain from them as snubbers Kelkara? Like I said, the only real difference I can see is that they allow for a shorter length of snubber. But since you're wrapping the line around this thing anyway, I doubt you're actually using much less line.

I don't have the line wrapped around the rubber. It has two lengths of line with spliced eyes looped around the eyes in the rubber. A chain hook on one end and another eye on the other which loops over a cleat.


The rubber is nowhere near as strong as the nylon line, but the line is the same size line as the rode I use if I run out of chain, so it had better not see anything close to breaking strain of the nylon. Under high loads the rubber stretches out to about twice its resting length, giving about 2ft of stretch.


It was on the boat when I bought it, so I started using it, and since it seems to work I have kept using it ... the real advantage is that I don't have to engage my brain to sort out another system that will also work. It would have an advantage in very shallow water since the chain hook would never reach the bottom, but I almost never anchor in less than 10m so that's not much benefit to me.

[slug]

I use a “snubber “ to get the chain load off the stem roller and to prevent the chain from jumping out of the chain roller

As for snubbing action...I see no need ..the chain catenary provides plenty of shock absorption

[tomfl]

Originally Posted by and4ew

I've been reading about snubbers and am now confused. I see them sometimes described as approx 30' of 3-ply nylon attached to anchor chain. Then I see pictures of these rubber things with rode spiraled through them. First question: are both these things "snubbers"?

I do understand that the purpose of a snubber into reduce shock loads. Second question: But if my anchor chain is attached to anchor rope and then to my boat doesn't the rope act as a snubber?

Note I don't have a windlass I usually just cleat the rope.

Maybe not the answer you want to here but there is a lot more you are missing than the difference between rope and rubber things.

First off there is the concept of ground tackle which is a system that includes more than just a rope/chain/anchor.

While I understand your comment about cleating off the rope I don't like that idea. The problem is you have only a single point of attachment; something that can be solved by using a bridle. This means you have two points of attachment. Not only does this reduce loads on the cleats and provide an extra safety measure; it also helps the boat sail on the anchor less. While I do have a catamaran with a windless and gypsy to handle both rope and chain I also have two cleats on each hull I attach the bridle to and a Sampson post I attach a third line to to secure the chain/rope. Depending on the situation I often use those rubber things on the bridle if I am expecting winds greater than say twenty knots. Even when anchoring for lunch I will use a bridle since the boat rides better and sails less. If you attach the anchor rope/chain to a single point unless it is at the exact center line of the boat and running through an anchor track it will be off center causing the boat to sail at the smallest change in wind and/or current. With a bridle the wind/current forces are reduced and spread out so sailing is greatly limited. Not to mention in nasty wind and current situations where one is fighting the other you can alter the length of one side of the bridle to control the orientation of the boat to the waves and reduce hull slap.

While it takes a few extra minutes to set up a bridle and rubber thing snubbers the added peace of mind is worth it to me.

[tomfl]

Originally Posted by Kelkara

I don't have the line wrapped around the rubber. It has two lengths of line with spliced eyes looped around the eyes in the rubber. A chain hook on one end and another eye on the other which loops over a cleat.


The rubber is nowhere near as strong as the nylon line, but the line is the same size line as the rode I use if I run out of chain, so it had better not see anything close to breaking strain of the nylon. Under high loads the rubber stretches out to about twice its resting length, giving about 2ft of stretch.


It was on the boat when I bought it, so I started using it, and since it seems to work I have kept using it ... the real advantage is that I don't have to engage my brain to sort out another system that will also work. It would have an advantage in very shallow water since the chain hook would never reach the bottom, but I almost never anchor in less than 10m so that's not much benefit to me.

I like the pix you posted. While I currently use a bridle with a rubber snubber on each side I like the idea of two lengths of line attached to the snubber. Thanks for the hint.

[Kelkara]

Originally Posted by tomfl

I like the pix you posted. While I currently use a bridle with a rubber snubber on each side I like the idea of two lengths of line attached to the snubber. Thanks for the hint.

Remember that my boat is not very big with corresponding smaller loads on the line.

One modification I have been thinking of, should I replace the nylon ... instead of having two separate pieces of line, is to use a single line with a loose loop between two knots that connect to the rubber. The loop will limit the maximum stretch, so hopefully prevent the rubber from snapping, or if the rubber does snap, prevent it from whipping back dangerously.

Of course judging the correct length for the loop could be tricky.

[Mike OReilly]

Interesting approach Kelkara, but I'm still not clear what the benefit of it is, other than to have a shorter snubber length. As you say, the rubber is weaker than the line, and it's an added complication, so why?

Seems to me the better approach is the more common one; just use a length of nylon. Most of us use 3-strand of some sort, although double-braid also works.

And for the record, what I thought people were referencing here is this kind of thing:

[Kelkara]

Originally Posted by Mike OReilly

Interesting approach Kelkara, but I'm still not clear what the benefit of it is, other than to have a shorter snubber length. As you say, the rubber is weaker than the line, and it's an added complication, so why?

As I said, it wasn't me that produced it but the previous owner ... but it works, so why not? And I've now tested it in a few serious blows.

The short snubber does have some advantages. You can try to calculate how much 1/2" 3-strand I'd need to get the same effect, it will certainly be much longer (and it's never a bad thing to keep less "stuff" in my crowded lockers) ... and the end of my snubber and chain-hook certainly don't drag across the bottom (as some people complain), in fact they don't even get wet unless the waves are building.

I have old dock-lines and spare rode I can repurpose as a long snubber if this one fails ... but so far so good.

[Chotu]

Originally Posted by Kelkara

I expect it depends on both the boat and the rubber thing. I've been using one on my 27ft 5ton boat quite satisfactorily, even in winds of 40kts. I expect it will break some day, but so far it's lasted me three years (plus however long the previous owner used it).

Definitely. I used them with great success on my old boats including a small catamaran and a 45' mono.

My current cat is a bit more rambunctious at anchor in a blow and rips them up.