Dyneema for an anchor to chain connection ?

[simonfraser]

Swivels seem to break, same with shackles, tie it on ?

The stuff is plenty strong enough if you bind it on well.

 

[CAPTAIN FANTASTIC]

I never had a broken swivel. Abrasion could be a problem; I wonder if you could combine swivel and dyneema.

 

[MM5AHO]

"swivels seem to break..." Wonder what type of swivel you're using. Some are just plain rubbish, and do break. There are some well made ones though that don't break.
Abrasion of a rope is a problem at the anchor.

 

[Plum]

Swivels seem to break, same with shackles, tie it on ?

The stuff is plenty strong enough if you bind it on well.

Although I have never used a swivel, I have never had a shackle break. I prefer the abrasion resistance of a metal shackle.

Www.solocoastalsailing.co.uk

 

[Old Bumbulum]

What do you mean, shackles tent to break? What sort of lousy shackles are you using for Heaven's sake?

 

[Gwylan]

Chinese sugar shackles?

 

[Tim Good]

Rated Kong Swivel plus Crosby shackle combo. The chain or anchor will break before they do.

 

[Neeves]

If you are using a swivel to take twist out of the rode when at anchor -

You are wasting your time and money, they do not swivel when lying on the seabed, they will ALWAYS leave at least 6 twists, there is not enough torque to overcome the friction.

If your anchor alway come up 'incorrectly' and the same way incorrectly - then your chain, shackle, anchor maybe aligned incorrectly.

The only 2 swivels that are not reported to break are those from Kong and Ultra, buy anything else and you may lose your anchor.

Use a Boomerang - you can make it at home.

http://www.mysailing.com.au/cruising/how-to-boomerang-your-anchor-right-back-at-you

Buy a Crosby shackle G209 A - you will not break it.

Search these forum and there is repetitive advise saying the same, often.

edit,

If you have twists in your chain (and you think this necessitates you wasting your money on a swivel) - when the anchor has broken free leave it to hang vertically from you bow roller, Sir Isaac and torque will untwists your chain.

close edit


Soft shackles or dyneema lashing for attaching to anchor to chain - theoretically this is a good solution (I"m not sure how this helps an anchor twisted on the chain???) but insufficient people appear to have tried it to define success, or not. Never having had a shackle fail and not using a swivel - I have never had need to even consider it (dyneema).

When many have tried it with success I may reconsider - but I doubt it.

Good Luck

 

[thinwater]

I've done some chafe testing of Dyneema related to anchoring, and it ain't that impressive side-to-side on rocks. In fact, 12-plait is barely different than polyester DB. In a nutshell, Dyneema has some impressive characteristics, but it isn't exactly what people think it is.

 

[Iliade]

I just used some 8mm dyneema as the rode for my anchored tender in Croatia (limestone bottom) for a fortnight. Evidently with the rode not quite short enough to lift the chain end off the bottom.

When I recovered it I reckon I was about two days from losing the anchor due to chafe where rode met chain.

 

[macd]

Swivels seem to break, same with shackles.

Same with tools -- if you buy cheap and unprovenanced. But tools generally aren't safety-critical.
Suggest you read Vyv's pages on connectors.

 

[Mikedefieslife]

Throw away the swivel, fit a Crosby shackle and call it a good job done.

I got rid of my Kong swivel last year, and the now the anchor always self rights when coming up. The swivel used to just cause problems.

 

[dgadee]

Throw away the swivel, fit a Crosby shackle and call it a good job done.

I got rid of my Kong swivel last year, and the now the anchor always self rights when coming up. The swivel used to just cause problems.

I had a Kong attached to anchor and it bent out of shape when I had a difficult retrieval. Have nothing now. If you do use one, put some chain between it and the anchor. I also did away with the tripping line after getting it caught round the prop. Simplicity is best for me, I think.

 

[Neeves]

In view of current posts, particularly by SAPurdie and Thinwater, I've reconsidered

I'll not by replacing my Crosby shackles with dyneema, nor will I ever use a swivel.

But it was an idea, dyneema shackles for (or in) an anchor rode, that was well worth airing.

Jonathan

 

[macd]

In view of current posts, particularly by SAPurdie and Thinwater, I've reconsidered

I'm rather surprised you needed to, Jonathan. Daft idea.

 

[noelex]

Dyneema is a great means of attaching the snubber to the chain, but it is not the right material for attaching chain to the anchor. As others have pointed out, the major advantage of chain is abrasion resistance and this would be reduced if Dyneema was substituted for the more common galvanised or stainless steel shackle or swivel.

Don’t give up on soft shackles. We are using them for many applications with advantages over the more traditional stainless shackles and other attachment methods. We have more than three dozen in use on the new boat.

If you are using a swivel to take twist out of the rode when at anchor -You are wasting your time and money, they do not swivel when lying on the seabed, they will ALWAYS leave at least 6 twists, there is not enough torque to overcome the friction.

Six twists is not likely to be an issue. It is when the chain starts to hockle that there are real difficulties. This is a very rare problem that you are not likely to see unless you anchor a great deal and have an anchor that is difficult to break free at shortish scopes.

Once the anchor is broken free the twists will spin out even without a swivel (sometimes very dramatically), but the gypsy cannot retrieve twisted chain, so all the twists become concentrated in the last section of chain. You need to achieve a very short scope, close to 1:1, before good quality modern anchors can be broken out. If the chain starts to hockle before a short enough scope is reached it becomes a frustrating problem.

A swivel will prevent this happening, but as it is a rare issue there is still a lot of appeal in a simple (metal) shackle.

 

[Neeves]

I'm rather surprised you needed to, Jonathan. Daft idea.

Actually use of a dyneema shackle between rode and anchor would be a topic to add to this current thread

http://www.ybw.com/forums/showthread.php?507020-Having-the-****-scared-out-of-you

But someone has already suggested I'm a woose - I'm trying to show I might have some backbone, somewhere.


Actually I'm not keen on the widespread use of soft shackles, everywhere and anywhere (its a bit like an invention needing to find an application to justify its existence) and have not yet found many applications where we find other method of attachment inadequate.

I can be a real Luddite at times. But the idea of retiring perfectly good, and proven, shackles, or whatever (I'd not save any weight as I would simply keep them) and having to make something else (without good reason) goes against my background.

If I find an application (or have one shown to me), that does not have me ****scared, I will consider it.

Jonathan

 

[GHA]

I just used some 8mm dyneema as the rode for my anchored tender in Croatia (limestone bottom) for a fortnight. Evidently with the rode not quite short enough to lift the chain end off the bottom.

When I recovered it I reckon I was about two days from losing the anchor due to chafe where rode met chain.

Which dyneema?

I've tried D12 max sk99 Marlow in a deliberately high chafe location on a spring and bow/stern warps for months with storms every few days - almost chafe free despite the beating it took.

Wouldn't use a dyneema shackle as a final connection between chain & anchor but as a snubber connection onto the chain it works really well.

 

[BelleSerene]

Six twists is not likely to be an issue. It is when the chain starts to hockle that there are real difficulties. This is a very rare problem that you are not likely to see unless you anchor a great deal and have an anchor that is difficult to break free at shortish scopes.

You need to achieve a very short scope, close to 1:1, before good quality modern anchors can be broken out. If the chain starts to hockle before a short enough scope is reached it becomes a frustrating problem.

A swivel will prevent this happening, but as it is a rare issue there is still a lot of appeal in a simple (metal) shackle.

I had to look this word up to know what you meant. Thank you for teaching me.

http://www.seatalk.info/cgi-bin/nau...?db=db&view_records=1&uid=default&Term=hockle

Re the anchor coming up the wrong way, I have always found that if you align the chain links from the anchor on its roller to the windlass and around the gypsy, the anchor will always - always - reboard the right way up, so long as you left it on a short length of chain on the way up to undo any twist it had made while on the sea bed. The force from each link of taut chain on its neighbour straightens out the twist. Many people just don’t notice that there’s a 90° twist in the chain between anchor and gypsy when they start off. You can correct it by hand with the anchor sitting on the roller and the chain a little slack.

Introducing a swivel ruins this, as even though the chain comes up straight in its last metre, there’s no knowing at what angle the anchor's shaft will be to it.

Of course, if I have to pay out some of the warp on the end of my chain, then the rotation of the chain when it meets the gypsy on the way back up is pretty random, so it’s worth checking later when the anchor is in situ on the roller.

 

[zoidberg]

I'm a wee bit surprised by the above. Surely peeps are able to identify places on a rope rode where chafe is likely - or probable - and secure some chafe-guard material there....? It's commonplace to do that where the rode leads through a fairlead, and I use lengths of recycled firehose with a securing cord at each end for that purpose. Cheap as chips and effective.

Why would this not occur to owners and be fitted to protect a rope-chain splice?