Galvanised D-Shackle

Ian_Rob · 21 Jan 2017

This has come up before on the forum but most of the suggested links are now dead.

I am after a 12mm Galvanised countersunk pin D-shackle with an Allen Key pin (or with the simpler square 'trawler pin') for my anchor but they are surprisingly difficult to find.

Plenty on EBay but of questionable provenance/strength. Plenty of stainless steel alternatives but I want it galvanised.

Grinding down a projecting pin version would be easy but would damage the galvanising and touching it up with spray is very short lived in my experiece. I would prefer a D-shackle to a Kong.

Any leads?

sailorman · 21 Jan 2017

http://www.mooringequipment.co.uk/shackles.html

Ian_Rob · 21 Jan 2017

Thanks for the link. The last but one image shows the flush type that I'm after but I want it galvanised rather than s/steel.

NormanS · 21 Jan 2017

I generally find that a small missing area of galvanising is protected by the adjacent galvanising.

doug748 · 21 Jan 2017

I use two of these for the anchor:

http://stainlessdirect.co.uk/index.php?main_page=index&cPath=25_144

Normally centre punch the pin for a bit of security. In my experience the surface treatment does not last long and I renew every few years. Which reminds me that mine are well rusted now.

You would have to contact them for any evidence of working strength, I think.

thinwater · 21 Jan 2017

So long as the pin is pointed up, what does flush matter? Since it is D it must be the second, not the one on the anchor.

Just curious.

Ian_Rob · 21 Jan 2017

Can you just explain what you mean by pointed up?

thinwater · 21 Jan 2017

^^ When you install the shackle in the anchor shank the wrench end can point either right or left. It will be a bow shackle with the bow through the shank to prevent side loading, which can weaken the shackle as much as 50%. If the chain is high strength (G43 or G70) you then install a second, smaller shackle that will actually fit through the chain (a shackle that will fit through G43 chain generally will not fit through the anchor shackle, and it if it does, it will tend to jam). This is a D-shackle. The wrench end can point either up or down. This is what I meant by "pointed up;" the wrenc end of the second shackle is normally pointed up.

NormanS · 21 Jan 2017

Ian_Rob said:
Can you just explain what you mean by pointed up?

I think it's safe to say that thinwater is assuming that as it's a "D" rather than a bow shackle, it's not the one on the anchor, but the next one. Accordingly you can choose to install it with the eye of the pin upwards, where it is unlikely to foul anything. There is a school of thought which feels that it is poor practice to use a "D" next to the anchor, as it reduces free articulation. Not half as bad as these horrible stainless fork end thingies. :disgust:

You beat me to it.

Ian_Rob · 22 Jan 2017

OK, thanks for clarifications. My anchor has been connected to the chain with one 12mm x 26mm x 43mm galvanised D-shackle from new. It is flush so it doesn't foul the bow roller. I have a galvanised Kong but as it is a fixed rather than a swivel version I have never used it, feeling that the fork arrangement, without the additional swivel, is a weakness.

Stainless Direct (as suggested by Doug above) sell a 12mm x 24mm x 49mm galvanised D which, assuming they can confirm an adequate breaking load, I'll probably go with.

thinwater · 22 Jan 2017

What is a Kong? They are a manufacturer that makes about 200 things. You've ruled out swivels, but that leaves about 195 possibilities.

Ian_Rob · 23 Jan 2017

thinwater said:
What is a Kong? They are a manufacturer that makes about 200 things. You've ruled out swivels, but that leaves about 195 possibilities.

They are these:

https://www.jimmygreen.co.uk/item/28527/kong-fixed-anchor-connector-galvanised

Mine is the KG-AC108 with a SWL of 2000Kg

NormanS · 23 Jan 2017

Ian_Rob said:
They are these:

https://www.jimmygreen.co.uk/item/28527/kong-fixed-anchor-connector-galvanised

Mine is the KG-AC108 with a SWL of 2000Kg

I see that even they recommend a bow shackle between the anchor and the Kong connector, which kind of begs the question, "Why use one of these things at all?"

vyv_cox · 23 Jan 2017

NormanS said:
I see that even they recommend a bow shackle between the anchor and the Kong connector, which kind of begs the question, "Why use one of these things at all?"

I have to agree, with a fixed connector as opposed to a swivel there seems little point in having it with a shackle. Interesting that Jimmy Green recommend a shackle. Only a couple of months ago they told a contact of mine that they could see no reason for doing it.

Ian_Rob · 24 Jan 2017

NormanS said:
I see that even they recommend a bow shackle between the anchor and the Kong connector, which kind of begs the question, "Why use one of these things at all?"

Exactly.

So far I haven't found a supplier who sells a flush, galvanised D-shackle with a declared/certified SWL.

Does one just take a suppliers word that a 10mm of 12mm or whatever size shackle is "up to the job"?

vyv_cox · 24 Jan 2017

Ian_Rob said:
Exactly.

So far I haven't found a supplier who sells a flush, galvanised D-shackle with a declared/certified SWL.

Does one just take a suppliers word that a 10mm of 12mm or whatever size shackle is "up to the job"?

I cannot answer your question directly but Jonathan Neeves may be able to. He is away at the moment and not participating in the forum but a PM should reach him in due course.

So far as your question is concerned I would concentrate on shackles made for lifting and hoisting. My tests of chandlery-bought galvanised shackles showed them to be pretty disappointing (see my website). However, stainless steel shackles from the same sources were far better and if you bought Wichard HT you would be buying one of the most reliable. Unfortunately I believe they have stopped making the type you want in this material. However, 3si sell high strength shackles (17/4PH I think) with socket head pins in their lifting and hoisting section https://www.s3i.co.uk/174socket.php.

What is your objection to stainless steel ones? Corrosion is not an issue with the combination of galvanised chain and anchor with stainless steel shackles on an anchor rode. After some years the galvanising may be corroded from the last couple of links but that's the worst it will get.

NormanS · 24 Jan 2017

Stainless/galvanised corrosion may not be a problem while the assembly is in the air, but is a recognised problem when immersed in seawater. You say yourself that it affects 2-3 links. Who wants that?

Maybe an extreme anchoring situation, but I regularly anchor for a period of one month, using two anchors in a Bahamian Moor, and made the mistake of using a stainless shackle at the join of the two rodes at 40m. On retrieval after only one month, the galvanising on a few links where the stainless shackle had been attached, was destroyed. Now that's a real nuisance, because it's not at the end of the chain, where it could easily be cut off, but in the middle of the rode.
Moral: stainless and galvanised should not be used together in seawater.

doug748 · 24 Jan 2017

Ian_Rob said:
Exactly.

So far I haven't found a supplier who sells a flush, galvanised D-shackle with a declared/certified SWL.

Does one just take a suppliers word that a 10mm of 12mm or whatever size shackle is "up to the job"?

Well I do. I am no engineer but I have made an in depth study of the matter.

The international unit of mass is the Fat Bloke.

The maximum predicted load on my chain is in the region of 4 Fat Blokes (ignoring storm surge and wave action, which we can).
The 8mm chain should be good for 20 Fat Men+, certainly 20 Fat Lassies.

Vyv's worst case for a suitable cheap shackle was failure at c 10+ Fat Blokes. The miserable sods that traduce my anchor have said it will drag at 2 Fat Blokes. I doubt I ever anchor in more than 1 Fat Bloke weather.

So I don't worry much.

thinwater · 24 Jan 2017

doug748 said:
Well I do. I am no engineer but I have made an in depth study of the matter.

The international unit of mass is the Fat Bloke.

The maximum predicted load on my chain is in the region of 4 Fat Blokes (ignoring storm surge and wave action, which we can).
The 8mm chain should be good for 20 Fat Men+, certainly 20 Fat Lassies.

Vyv's worst case for a suitable cheap shackle was failure at c 10+ Fat Blokes. The miserable sods that traduce my anchor have said it will drag at 2 Fat Blokes. I doubt I ever anchor in more than 1 Fat Bloke weather.

So I don't worry much.

That's funny! The only flaw in the logic is that I've 10 fat blokes sneak upon me when I least expected it. My solution is a nice long snubber that keeps the load down to about 2-3 blokes

I've done a lot of anchor testing, and given the huge variability of results in crappy bottoms, the solution may be reporting data in variable units.

Len Ingalls · 24 Jan 2017

Crosby http://www.liftingsafety.co.uk/category/crosby-anchor-shackles-bow-and-d-1095.html

Galvanised D-Shackle

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