Anchor Shackle

[JimC]

Apologies if this has been covered before. I use a D shackle to attach the chain to my anchor. The pin of the shackle catches in the bow roller when recovering the anchor so I would like to change it for one of those flush-pin shackles that you tighten up with an allen key. My query is; how does one lock such shackles? Using Locktite or deforming the threads with a centre-punch are two possibilities that spring to mind but neither seems to me as secure as wire-locking a conventional shackle.

 

[vyv_cox]

Apologies if this has been covered before. I use a D shackle to attach the chain to my anchor. The pin of the shackle catches in the bow roller when recovering the anchor so I would like to change it for one of those flush-pin shackles that you tighten up with an allen key. My query is; how does one lock such shackles? Using Locktite or deforming the threads with a centre-punch are two possibilities that spring to mind but neither seems to me as secure as wire-locking a conventional shackle.

I have carried out some trials of Loctite 242 on anchor shackles and connectors. I use a Wichard D shackle with a countersunk allen screw pin and a Kong swivel which is assembled using a countersunk screw. I sail full time May to October, mostly anchoring overnight.

In the 2009 season I assembled these items using the Loctite. At season's end I disassembled them and could not detect any reduction in torque required to turn the screws.

I would not recommend this approach for anything more permanent, such as a mooring, but for anchoring it seems perfectly adequate.

 

[JimC]

Thanks for that Vyv, I'll get some of the Locktite and also centre-pop the thread, being of a pessimistic disposition.

 

[Salty John]

An alternative would be to change the D shackle for a bow shackle, where the pin doesn't protrude beyond the width of the shackle.

 

[JimC]

An alternative would be to change the D shackle for a bow shackle, where the pin doesn't protrude beyond the width of the shackle.

I think that's called lateral thinking - Thanks!

 

[VicS]

I think that's called lateral thinking - Thanks!

Except that I think you will find that the pin is the same length as a D shackle but the shackle itself is wider and may not come over the roller.

 

[craigsmith]

Using a bow shackle may help depending on the behavior on the roller - better a soft body finding its way than the edge of the pin.

There are other shackle pin configurations available, such as safety-bolt arrangements. If you look at the below link at the photo at the bottom you will see a custom made arrangement made by replacing the pin with a bolt and hand-machining the bolt head with a hole for seizing and a rounded head to minimize profile. Harder to do with smaller gear though.

www.rocna.com/kb/Shackles

 

[Poignard]

.... deforming the threads with a centre-punch ....

If you are prepared to consider that option you might as well follow the advice of Eric Hiscock in 'Cruising Under Sail' and fit an ordinary shackle, then saw off its head and finally rivet over the protruding thread with a ball pein hammer. That won't come undone and, being mild steel, it will be easy to saw it off if you ever need to.

 

[john_morris_uk]

If you are prepared to consider that option you might as well follow the advice of Eric Hiscock in 'Cruising Under Sail' and fit an ordinary shackle, then saw off its head and finally rivet over the protruding thread with a ball pein hammer. That won't come undone and, being mild steel, it will be easy to saw it off if you ever need to.

I did that once - but you lose the galvanising where you have sawn through and the thing quickly goes rusty and makes a mess...

 

[Poignard]

I did that once - but you lose the galvanising where you have sawn through and the thing quickly goes rusty and makes a mess...

That's a good point. I was planning to follow EH's advice but now I will think again.

Thinks: One possibility is to use one of those shackles that have a hex-headed bolt as a pin. I have seen them on sale somewhere - maybe it was in the fishermans' co-op in Cherbourg.

 

[KellysEye]

Another way to do it is if you have stainless 'cheeks' on the bow roller get a block of wood and a club hammer and widen them.

 

[vyv_cox]

That's a good point. I was planning to follow EH's advice but now I will think again.

Thinks: One possibility is to use one of those shackles that have a hex-headed bolt as a pin. I have seen them on sale somewhere - maybe it was in the fishermans' co-op in Cherbourg.

Nothing to stop you doing exactly the same with a stainless steel shackle. My testing showed stainless shackles generally to be stronger and more reliable. Will hacksaw easily.

 

[Poignard]

Nothing to stop you doing exactly the same with a stainless steel shackle. ....... Will hacksaw easily.

I had a s/s shackle for a while but it caused the endlink of the chain to rust.

Also I find mild steel much easier to saw through than s/s. The downside is that you have to take it off the boat to do it.

 

[JimC]

An alternative would be to change the D shackle for a bow shackle, where the pin doesn't protrude beyond the width of the shackle.

It's only just occurred to me that, when recovering the anchor, it's the pin end of the shackle that's first to reach the bow roller; so surely the fact that the bow is as wide as the pin would be no help because the bow hasn't got there yet (I have the pin through the end link of the chain and the body of the shackle through the slot in the anchor stock).

 

[alahol2]

I have been using one of these for the last several years... http://www.s3i.co.uk/rapide_link_standard.php

 

[JimC]

I have been using one of these for the last several years... http://www.s3i.co.uk/rapide_link_standard.php

Very interesting, I note that size for size the SWL is higher than for the well-respected Kong swivel connectors. But how do you lock them?

 

[alahol2]

Very interesting, I note that size for size the SWL is higher than for the well-respected Kong swivel connectors. But how do you lock them?

I just crank it up hard with a spanner. I've never yet had it loosen, there's quite a bit of thread involved. I wouldn't use one on a mooring but for anchoring they are fine.

 

[HermanD]

Locking countersunk shacklebold

To lock a countersunk shacklebold demands a little work.
I use a M10 bolt for 8mm chain.
Drill a 1,5mm hole see photo 1
Grind with a Dremel a small channel in the underside off
the bold head. Remove sharp corners.
The result photo 02+03. I used a copper wire for the photo
contrast. Normally use monel wire.
This will weaken the boldhead a little, but normally there will
be not much tension on the head. Only shear load on the bolt.
So you can now lock the bold.

 

[tp_zoveel]

Or, you could skip the shackle altogether and splice the rope to the chain. That way you won't have anything that can get stuck in the bow roller.
How to: http://www.bluemoment.com/warpchainsplice.html

I did this, works splendidly. It took me about an hour to saw through the completely rusted shackle, and then another 40 minutes to do the splice-thing.

 

[Xskipper]

Why not use a hammer lock?

Secure with nothing to catch on rollers etc...