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Old 27-09-2012, 10:53   #16
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Re: What size for snubber?

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Originally Posted by estarzinger View Post
..........see line from one cleat up thru the chain near the bow and back to the other cleat...............
I like this idea for convenient, light use, but I would be wary of the snubber line chafing through in any kind of a storm situation or longer term use.
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Old 27-09-2012, 11:25   #17
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Re: What size for snubber?

On our 42 footer we use 14mm (9/16") three strand nylon in a 25 foot length. any thinker is just less springy. You don't need to worry too much about strength, chafe is the real enemy. Have chafe guards and have enough line so that you can ease it about 30 cm every so often in a blow to relieve chafe points. In calm anchorages, you only need a few feet or meters out to give plenty of elastisity and to stop the chain from yanking and making terribly noises when the boat pitches a little. I have an eye splice in the bitter end so that I can just drop it around one of the forward cleats and then I cleat the line off to my desired length. That way in the dark if the wind comes up I can let out more line and not have to worry about dropping it overboard. Even in 30 knots of breeze, 6m (20 ft) of 14mm gives plenty of spring. As Evans says above even 11m can be enough. I used 11mm for years when climbing and it never failed me, even with humungous shock loads....

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Old 27-09-2012, 13:17   #18
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Re: What size for snubber?

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I like this idea for convenient, light use, but I would be wary of the snubber line chafing through in any kind of a storm situation or longer term use.
Agreed . . . I have been watching for that . . . . however, so far (4 months of usage - including one 3 day period is an anchorage with too much fetch and a pretty big wave pattern) there is not even a mark on the line where it goes thru the chain . . . . I believe because it does NOT saw back and forth on the chain - that point stays stationary because the stretch on both sides is the same.

I think I would definitely switch to our regular snubber in a big blow, primarily to get more elasticity. But so far this 'new' idea is working better than I thought it would as an 'every day' snubber.
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Old 28-09-2012, 13:05   #19
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Re: What size for snubber?

Evans,
I thought that a side benefit of a snubber was to prevent the noise of the chain dragging sideways on the bottom from being transmitted to the hull.

If the snubber is connected to the chain on the deck, then any noise should be transmitted by the chain to the bow roller. Did you notice anything?

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Old 02-10-2012, 04:29   #20
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Re: What size for snubber?

On a 38ft 6t cat we use a 12mm braided nylon line down each side deck attached to the stern cleats. We run each line through the stanchion bases. We have turning blocks on each bow and run to a central chain hook. We have the snubbers running through hose at wear points. As everone says- its amazining how much they stretch. The lines are permenantly set when we cruise long term.

We have enough spare nylon to replace, we have had bridles snap.

The biggest problem on a cat is getting the length right to sit under the kicker wires of the prodder (bowsprit) and no be so long they rise up and rub (and wear) when under load.
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Old 02-10-2012, 04:59   #21
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Re: What size for snubber?

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Originally Posted by estarzinger View Post
In terms of snubbers, I have been trying something new this summer, shown below (see line from one cleat up thru the chain near the bow and back to the other cleat). My objective was to stop having to mess around with the hook or rolling hitch and make it easier both to set and recover. It's worked fine so far, but I still don't know if its a good idea or not. It certainty takes the load off the windless, and adds some elasticity (but less than a much longer snubber).

Attachment 47299
Do you have a chain stopper of some kind, besides the snubber? I would certainly want something besides the snubber protecting the windlass from the loads.

I have a stainless chain shackled to my inner forestay chainplate which terminates in a chain hook -- after putting the snubber on, I belay the chain with that to prevent the windlass from being broken in case the snubber breaks (which has happened to me).

I have two snubbers -- a heavy long one for bad weather, and a light shorter one for good weather. The heavy long one is about 24 mil (about 1") and is about 15 meters long. The light shorter one is 14mm (or 16mm -- can't remember exactly) and 6 meters. Both are nylon octoplait.

One problem I have which probably many others have is how to belay the snubber. As others do, I suppose, I use a bow cleat, but it does not lead fair over the second bow roller -- I have to use chafe protection and I'm still not happy with it. I have experimented with looping it over the inner forestay chainplate, but that has relatively sharp edges -- also not ideal. I really miss having a Samson post -- something every boat should have IMO.
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Old 02-10-2012, 15:16   #22
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Re: What size for snubber?

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One problem I have which probably many others have is how to belay the snubber. As others do, I suppose, I use a bow cleat, but it does not lead fair over the second bow roller -- I have to use chafe protection and I'm still not happy with it. I have experimented with looping it over the inner forestay chainplate, but that has relatively sharp edges -- also not ideal. I really miss having a Samson post -- something every boat should have IMO.
Dockhead, you have probably thought of this but do you have a place where you could put a block to gain a fair lead? Blocks tend to do quite well in chafe because there is almost no relative movement between the sheave and the line and they provide a decent radius. The trick is having a strong attachment point in the right place for it to work. Just a thought.
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Old 02-10-2012, 15:49   #23
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Re: What size for snubber?

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Dockhead, you have probably thought of this but do you have a place where you could put a block to gain a fair lead? Blocks tend to do quite well in chafe because there is almost no relative movement between the sheave and the line and they provide a decent radius. The trick is having a strong attachment point in the right place for it to work. Just a thought.
We would agree with this, a block can be positioned in a variety of places if you use a strop.
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Old 02-10-2012, 15:56   #24
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Re: What size for snubber?

The main purpose of a snubber is to help silence the anchor chain noise.

I like a snubber length so it hooks onto the chain just above the water and the loop tied with a figure 9 knot (a figure 8 with an extra turn). The loop is passed over a cleat, bollard or samson post on deck. Not the winch capstan!

Mine is a 14mm Nylon Static double braid covered by fire hose over the bow roller. The advantages of static over old dynamic climbing rope is less chafe. I had failures when I used dynamic in the past. I believe the springy effect of a snubber may just help the anchor to break free much like the effect of a snatch strap on a bogged four wheel drive.
Just let more chain out, its weight will soften the gusts.
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Old 02-10-2012, 16:30   #25
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Re: What size for snubber?

Snubbers can be used to remove the noise of the anchor chain grinding on the bow roller - but this simply increases your comfort - and any old bit of rope will do.

The real advantage of a snubber is to dampen the snatch loads that develop when your yacht surges, or rises and falls in waves, and you are unable to extend your chain, someone too close, small anchorage, at full extent of chain already. At around 25 knots of wind under normal length and diam of chain carried - most of your chain will lift off the seabed and you will suffer from snatch loads - the yacht pulling hard on an in-elastic chain. If you unusaully carry 100m of 14mm chain on a 35' yacht - I suspect the chain will still be on the seabed - so my figures are not hard and fast!

A snubber, however it is used, will take the load of your anchor windlass, capstan etc. The windlass is commonly not designed to take snatch loads. A snubber would normally be attached to a strong point, we use the aft horn cleats but you could use a sheet or halyard winch, or better 2 of them - a snubber down each sidedeck will be better than 1 snubber.

Good snubbers work like a bungy jumpers cord - when you reach the bottom of the fall the momentum of the jumper (or that developed by your yacht) is absorbed by the elasticity of your bungy (or snubber). Short bits of nylon are a waste of time. You need around 10m to get elasticity (or enough give to the make the difference). If the bungy is too thin its lifespan will be short (but it will stretch more), if its too thick - you will not enjoy the stretch. The thickness is usually found by trial and error - but for a 35' yacht start at 10mm - and you need that 10m!

A 45' yacht in 30 knots of wind and a 7:1 rode ratio (measured to bow roller) will enjoy snatch loads of 300kg - any real elasticity will reduce those loads to less than 100kg (much of which is the weight of the chain).

An alternative are Shockles - I think their address is www.shockles.com they are American but available, ex stock, in the UK and Oz.

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Old 02-10-2012, 17:37   #26
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Re: What size for snubber?

Same size boat and chain here. Another thought for attaching the snubber to the boat.

We use a 5/8" nylon 3 strand line with an eye spliced into each end. Once the anchor is set, I tie the middle of the line to the chain then run the snubber through the bow chocks and drop the eyes over the mooring cleats, effectively giving us 2 snubbers. If one side chafes, the other will still hold. Then I loop the chain over one of the mooring cleats so if both lines chafe, the windlass is still protected.

As a side benefit, it seems to help dampen any sailing on the anchor.

As to length, we have 2 snubbers. In the Chesapeake, I tend to use the shorter one that won't quite reach the bottom in our typical anchorages. Got tired of scrubbing that soft Chessie mud off the line. Also have the added benefit of being able to cast off one and tie on the other if it's ever needed.
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Old 02-10-2012, 17:54   #27
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Re: What size for snubber?

While cruising for 7 years (East Coast US, West Coast FL and Bahamas, I never used a lot of chain. (15' - 20' on each anchor) Anchored in 2 Hurricanes with no problems. I believe in rode stretch for absorbing shock loads, so as not to yank the hook out.
If I was doing it again, I would use 50' of chain and the rest nylon. I used an all chain rode, and had to deal with snubbers, and it was a pia. With 50' or less, you always let out enough rode to have the nylon to absorb shock, and noise. If it starts blowing, just let out more rode. Done.
If I was sailing around the world (which for some reason, a lot of sailors feel they need to equip there boat, as if they were) I would carry at least 1 all chain rode.
Just my .02
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Old 02-10-2012, 18:30   #28
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Re: What size for snubber?

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While cruising for 7 years (East Coast US, West Coast FL and Bahamas, I never used a lot of chain. (15' - 20' on each anchor) Anchored in 2 Hurricanes with no problems. I believe in rode stretch for absorbing shock loads, so as not to yank the hook out.
If I was doing it again, I would use 50' of chain and the rest nylon. I used an all chain rode, and had to deal with snubbers, and it was a pia. With 50' or less, you always let out enough rode to have the nylon to absorb shock, and noise. If it starts blowing, just let out more rode. Done.
If I was sailing around the world (which for some reason, a lot of sailors feel they need to equip there boat, as if they were) I would carry at least 1 all chain rode.
Just my .02
I agree.

Except in Oz no-one would use any synthetic in their rode if they are visiting the reef and at some stage we all go there, weather's good in winter and its beautiful. Coral, even a loose lump, can eat synthetics overnight - which is why we nearly all (maybe all) have all chain rodes. But in the UK - mixed rodes are the norm - though I have never worked out how they cater for deployment of different lengths of rode (sometimes it must be all chain and sometimes an awful lot of synthetic).

We carry all chain as our primary rode but have 30m of chain and 40m of nylon (spliced together) as our secondary (and we have enough spare to add another 100m, heaven forbid, which is more commonly used if we need to tie to a tree).

Jonathan

ps 4 x 4 snatch work differently, or the same, but different. You attach the snatch tape and have one vehicle move away from the one that's stuck. The tape absorbs the 'energy' the pulling truck simply moves away and away - at some point that energy is transferred in one slug to the stuck vehicle and it leaps out (with a bit of help from its own engine). Using the same system on a yacht works becuase the anchor is actually fixed, the snubber absorbs the energy and it is then transferred to the yacht (not the anchor) - so the yacht moves forward rather than the anchor pulling out - but you do need a decent anchor, Fortress, Spade, Supreme, Excel, SARCA (the jury is still out on the Boss, I'm convinced it works but having nothing to justify my convictions) in any event plenty to choose from without buying something questionable.
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Old 02-10-2012, 19:29   #29
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Re: What size for snubber?

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One problem I have which probably many others have is how to belay the snubber. As others do, I suppose, I use a bow cleat, but it does not lead fair over the second bow roller -- I have to use chafe protection and I'm still not happy with it.
Dockhead, I've got the same problem. The snubber makes a slight bend on the anchor roller where it enters the channel. If I run snubbers through the chalks they rub on the stainless chainplate on the stem when the boat yaws. So either way I need to rely on chafe gear to protect the snubber from a stainless steel corner.

If the snubber is over the anchor roller, could I run it through a block on a strop on the opposite bow cleat? I wonder what the loads would be like on the block and the opposite cleat? They wouldn't wouldn't be any greater than on the cleat where the snubber itself is belayed, I presume.
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Old 02-10-2012, 20:35   #30
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Re: What size for snubber?

Unless I have missed it , there has been no mention of how much chain to put out after you have attached your snubber. On another thread there was mention of putting out a good big loop of chain, which is not the proper method at all. If my memory serves me right , nylon has a safe stretch of about 30 percent (Gord correct me if that is wrong) so if you are useing a 30 foot snubber, that leaves about 9 feet of stretch before it overloads the rope. To be conservative you would only let out about 7 or 8 feet more of chain after the snubber took up the initial load. The reason for this is if the snubber breaks, chafes thru, cleat pulls out of deck, etc. you dont want a lot of loose chain to allow your boat to build up momentum before it takes up on the chain. The 7 or 8 foot of stretch that nylon gives will take all of the snap load out of the chain, but if the nylon breaks the boat wont have enough room to build up a chain breaking surge. As for size, I would use whatever size nylon would be correct for anchoring on nylon for your size boat. Really good chafing gear is probably more important than the diameter of the snubber. Just another 2 cents worth.____Grant.
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