Anchor snubber- long stretchy rope or rely on catenary

The type of rope in a snubber is important. Polyester and Polyproylene have low elasticity, so they don't absorb shocks as well as nylon, which has fabtastic stretch.
But the downside of nylon is that it's not as UV resistant as polyester.
 
I find that my main reason for using the snubber is not to combat the effects of swell but to prevent the boat being driven onto its chain in a wind against tide situation. It depends where you anchor, but on the east coast hidden away in the creeks in a boat with a straight stem, being forced onto your chain is much more of a problem than snatching in a swell. Judging by the score marks you see on the bows of other boats I am not alone. If you attach a chain hook and let the chain out so that the hook lies below the boat all you rub against under tension is a length of multiplat rather than 10mm chain.
 
PeterR said:
I find that my main reason for using the snubber is not to combat the effects of swell but to prevent the boat being driven onto its chain in a wind against tide situation. It depends where you anchor, but on the east coast hidden away in the creeks in a boat with a straight stem, being forced onto your chain is much more of a problem than snatching in a swell. Judging by the score marks you see on the bows of other boats I am not alone. If you attach a chain hook and let the chain out so that the hook lies below the boat all you rub against under tension is a length of multiplat rather than 10mm chain.
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I find the number of people using 10mm chain quite extraordinary - does everyone have enormous yachts now in the UK? :)

Jonathan
 
Interesting the numbers of people now using long snubbers and the numbers 'hiding' that length along the deck, somehow. Snatch blocks are good idea to manage the run and keep the decks clear. I would encourage use of a back stop chain lock or short snubber - in case the 'main' snubber fails. I think it was GHA who starts his snubber at the bow, back to a transom mounted block and then forward to a chain hook - this givers him a snubber 2 times deck length - great idea. Even better if he runs up through the stanchion bases as he can leave it 'rigged' permanently - it would be a bit of a faff to do late at night in the rain :( - every time at anchor.

Its also amazing how many variations - there are lots of right ways to rig a snubber - 'Just do it'! You know it makes sense!!

And use nylon, accept there will be UV degradation - and carry a spare. Its elasticity makes it too good to worry about the sun.

:)

Jonathan
 
13m boat. 60 m of 10mm chain. Snubber is an old nylon mooring line about 20m long.
I tend to put the full snubber out and drop exta chain. This acts as a kellet in moderate conditions.
 
MM5AHO said:
A rubber snubber of perhaps 3-400mm long would need to have about 250% stretch to do the same as a nylon rope.
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Both Prof Knox and I did some work, independent of each other. if you take a rubber dogbone thing and use with the appropriately sized nylon then the dogbone is equivalent to about 2m of nylon. So to equal 10m of nylon you would need 5 dogbones (and 5 dogbones are extraordinarily heavy - 'slightly' more expensive than the nylon, look ugly and take up more room). They are useful for a mooring, to a pontoon, as they offer their elasticity in a short length - but for anchoring you usually have plenty of room.

They have an additional disadvantage - if you use them correctly they are designed to take a well defined load - beyond which you are dependent on the elasticity of the cordage, so they tend to have a windspeed limit. Nylon offers its elasticity until it fails - and the failure tension will be well beyond anything you are likely to experience (through cyclic loading reduces the life of nylon (which is why you carry spares). But just when you need the extra elasticity - dogbones will stop working.

If you only use, incorrectly in my view, a very short snubber - then they would be advantageous - but otherwise - yes they work - with the foregoing provisos.

Jonathan
 
I, and others, have been advocating use of retired climbing ropes as a snubber. Yngmar has pointed out this idea might not travel too well to a country where their mother tongue and leisure pursuits might not quite match with those of the UK (and Australia) and furthermore the idea of using a retired climbing rope in an anchor rode might be a very alien concept. After all - using a long snubber to part replace catenary is hardly wholeheartedly accepted.

In fact the idea of a climbing rope and an anchor rode might be an alien concept anyway - and I wonder if even the ideas of 'indoor rock climbing' is an alien idea to many.

But being a convert I though this lightweight article from The Guardian might be a bit of light relief from all things marine and might be a good way, the climbing gym, for those who have a fear of heights to overcome their fears of mast climbing.

https://www.theguardian.com/lifeand...rldwide-sensation-what-is-its-dizzying-appeal

Jonathan
 
My boat is 13m and had a 25kg Delta anchor on 10mm chain. Snubber was off the shelf from a well known Devon chandler about 2.5m long. I religiously used it although it seemed to make little difference. All replaced 6 weeks ago with a 27kg Knox and 100m of 10m chain. I got a new snubber from Knox although the first disappeared from the package and replaced without question (thanks Geoff!). New one goes right back to a stern cleat via the bow roller. Stretch of the nylon rope is surprising and makes the night quieter and more peaceful. Used about 20 nights so far in a maximum wind of 45kn. Big improvement!
 
We always rig a snubber when anchored, mainly to stop the noise of the chain on the stemhead fitting at night (we sleep in the forecabin). Our boat is 8.2 metres in length. The snubber is a 7 metre length of 3 strand nylon, with a rubber mooring compensator attached to it.

As others have mentioned, this line can be used for other purposes such as a spring when tied up to a pontoon.
 
Pasarell said:
My boat is 13m and had a 25kg Delta anchor on 10mm chain. Snubber was off the shelf from a well known Devon chandler about 2.5m long. I religiously used it although it seemed to make little difference. All replaced 6 weeks ago with a 27kg Knox and 100m of 10m chain. I got a new snubber from Knox although the first disappeared from the package and replaced without question (thanks Geoff!). New one goes right back to a stern cleat via the bow roller. Stretch of the nylon rope is surprising and makes the night quieter and more peaceful. Used about 20 nights so far in a maximum wind of 45kn. Big improvement!
Click to expand...

Interesting.

You used a 25kg Delta, presumably for a number of years and if you did use it for a number of years it must have suited your needs. You have had plenty of opportunity to upgrade as NG anchor have been around for almost 15 year, and almost 30 year if you include Spade and Fortress You then bought an anchor that is reportedly much better and any of these new anchors cost much, much more than a Delta - yet you bought a bigger one, why? (Why the bigger one?)

Of course you are happy - and the snubber simply adds to any improved performance as with that extra length adding extra elasticity you will no longer snatch at anchor.

I am not questioning the performance of the anchor - I think them great - I just wonder at the thought process.

Having said that with 100m of 10mm chain in the bow - then the anchor seems a bit paltry! and the Delta very undersized Now there's a contradiction! :)

Jonathan
 
Hi Jonathan
I did use a 20kg Delta on my old boat in the UK for about 6 years and it was fine. This boat was new to me in Greece last year and the 25kg Delta came with it. For some reason I wasn't happy with it's performance, especially after it popped out when in a 180 wind change of about 20kn. Decided to invest in a NG anchor and upgrade from 50m of old chain to new 100m at the same time. Chain here comes in multiples of 50m so I could cut a bot off but I have room for it and paid for it. Decided on the Knox based on various comments here, many yours, and the fact it was British made. Cost including delivery was only about £30 more than a 25kg Rocna. Knox comes in 19 or 27kg sizes. Discussed with Geoff at Knox and he agreed the 19kg would almost certainly be fine in Greece but 26kg would be better if I was in more challenging areas. Since I was already spending quite a lot of money the larger size didn't make too much difference, and when it blew 45kn much of the 4th night of use it felt like a sensible investment!
Overall I've reduced weight of anchor carried as the boat came to me with the Delta and a Bugel of about 17kg also on the foredeck. Both Delta and Bugel have now gone and my 2nd anchor is a Fortress FX23 mounted on the pushpit.
All seemed to make sense to me!
Peter
 
Peter,

Makes sense to me, as well. I just wondered!

The Delta was part developed as a result of the competition introduced by the Bruce. Part of the marketing at the time was the simple demonstration that you can catch a tennis ball in a Bruce (with a little practice) but cannot achieve the same result with a Delta - the same argument then as now. I note that Lewmar are sticking with this philosophy and their prototype new anchor is also a convex design. The Delta was better in terms of setting than the CQR but was rapidly eclipsed (for a variety of reasons) by Spade and Fortress - and these latter 2 seem to be surviving the test of time.

Anchor makers have a difficult time - they are confident of their product (or one hopes so) but need to be cautious - as they simply do not know how their product is going to be used, nor where. I think Geoff is exhibiting prudence and also is not going to stick his neck out - but give him a few more years at the helm and maybe we will see a change :)

I think that the 27kg Knox is unnecessary - and in your 45 knots blow - a smaller model would have held - though would have set more deeply - and maybe slightly more difficult to retrieve. But we will never know - and you sleep well (which is what it is all about!). So guessing on performance of a smaller model - its well, guessing :)

I'm still twitchy that the holes that allow the pockets in the fluke to drain might become blocked and the pockets retain water (and long term - rust). Stick a hose in them when you remember! I mention this as I saw another anchor that has a pocket when stowed had rusted through where the puddle collected, it had no drain holes. The anchor is exceptionally well constructed and strong - that shank is one of the strongest I have seen. The galvanising seems very good, possibly negating my fears of rust in the pockets!

I have not yet been defeated by ours, 13kg, but there is no perfect anchor, yet, maybe Knox??? - but until proven undefeated - assume it might have an Achilles heel. Our seabeds tend to be on the soft side - we don't have hard seabeds (or not that I have found) where any anchor would be defeated.

Jonathan
 
Never used an anchor pennant until this summer’s cruise around the Small Isles. For this trip I made up a 3-strand nylon line, chain hook at one end, spliced eye at the other, running from a stern mooring cleat to the water over the bow.

Anchored off Eigg it was a bit blowy; I don’t have wind instruments, but the forecast said F5 occasionally 6 (nothing, I know, compared to some). We were anchored in about 4m, low water, with 25m of 5/16” chain (she’s an old boat).

Before rigging the anchor pennant we could feel the boat snatching back hard on the anchor. Once rigged, things quietened down and the amount of stretch on the nylon pennant was significant. I rigged a snatch block to a stantion base and ran the line through it to prevent the nylon from wearing through the coach roof paint.

Next morning we had a helluva job getting the anchor (9kg Knox, no windlass) out of the mud/sand; we could see it clearly, buried up to the chain shackle.
 
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Porthandbuoy,

Interesting description.

25m deployed. 4m depth, at low water. Assume 1m from bow roller to the water. Add in 2m tides

You were anchored at high tide with a rode at 3:1 (maybe less).

Why not more chain deployed?

A good endorsement for Knox (not what you were intending!). We can bury our anchors (whichever we use but including a 13kg Knox), completely, and around 2m of chain. We have marked our chain at 1m intervals for the first 5m so that we know how much chain we have buried.

It would be, maybe, even more interesting to know anchor and yacht size - that is pretty hefty chain! (but despite its weight - still snatching before the snubber was applied, another endorsement for snubbers and questioning the value of heavy chain?

Jonathan
 
Neeves said:
Porthandbuoy,

Interesting description.

25m deployed. 4m depth, at low water. Assume 1m from bow roller to the water. Add in 2m tides

You were anchored at high tide with a rode at 3:1 (maybe less).

Why not more chain deployed?


Jonathan
Click to expand...

25m from the water, not bow roller. Neaps, @ 1.2m, so nearer 5:1. Not a lot of swinging room. Boat's a Nicholson 26, long keel, 4.5 tons or thereabouts.
 
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