Modifying Anchor Shackles

[No Ice]

Jon Jo

Thanks for the link being able to obtain them in the UK is easy for me.

PS Im not a whiskey drinker, The boat got its name "No Ice" for another reason which is to long for this thread, maybe we should start a thread of why our boats got their name when we finally solve all the questions about anchors, chain and shackles!!

Brian, No Ice

[Pete7]

Originally Posted by JonJo

I'm buying Crosby shackles from here, in the UK

Crosby G-209A Galvanised Screw Pin Bow Shackle 2000 kgs WLL - 221.017.450

If you want stainless shackles - ask - they have a second company that deal in stainless. Jonathan

Just be aware that they are imperial sizes and in the UK chain is metric. Ran into this problem using one of there chain joining links. The joining link was actually slightly too big for the 8mm chain and doesn't swivel freely.

Still they deliver small orders quickly.

Pete

[HappyMdRSailor]

Originally Posted by No Ice

Jon Jo

Thanks for the link being able to obtain them in the UK is easy for me.

PS Im not a whiskey drinker, The boat got its name "No Ice" for another reason which is to long for this thread, maybe we should start a thread of why our boats got their name when we finally solve all the questions about anchors, chain and shackles!!

Brian, No Ice

Brian,

There's a good thread on this that dropped off the radar a while ago...
Bring her back to life!

http://www.cruisersforum.com/forums/...ou-104845.html

[JonJo]

Originally Posted by Pete7

Just be aware that they are imperial sizes and in the UK chain is metric. Ran into this problem using one of there chain joining links. The joining link was actually slightly too big for the 8mm chain and doesn't swivel freely.

Still they deliver small orders quickly.

Pete

They are also the easiest way for me, in Oz, to source as well (which says little for people here and Americans - all credit to Tecni).

Conversion of imperial sizes to metric is a real can of worms and I am at fault for not emphasizing the problem. My recommendation is to size the hole in your chain, ring them up and ask them to physically check whatever it is you want. They appear very sensible, sympathetic and practical. This also goes for your anchor shank hole - note lifting shackles have shorter shackle pins, so a smaller slot to fit onto your anchor.

But if you want a gal 3/8th inch HT 2t shackle as far as I can make out it will be American (note short tons not metric tonnes). There are other manufacturers (in America and I asure you can buy them in/from China?!) and the 3/8th inch pins are all of varying sizes, some are slightly smaller, some slightly larger. But a 3/8th inch pin should fit a 8mm chain. I have three different, manufacturers, imperial gal 3/8th inch shackles, 1t and 2t and they all fit an 8mm chain. I also have a 5/16th inch ACCO 'C' link which fits 8mm chain (but I actually would not use one in an anchor rode, except in dire emergency!).

No Ice, let us know how you get on.

I have just ordered from Tecni, I'm simply a satisfied customer.

Jonathan

[conachair]

Originally Posted by No Ice

Question for Conochair.

I see you are in the UK, please let me know where in the UK i can buy the quality shackles you refer to?
Also you say you use a Rocna anchor, which model and what type and size of chain?
Im in the process of buying a Rocna 40KG for my boat a Grand Banks 42 Max weight 52000Lbs i have 10mm Galv chain which i think is G3 grade, what shackle would you suggest i use?

Brian

Hi, in industrial lifting everyone goes for Crosby shackles, I use Flints in London quite a lot, mainly because I know them, they're a bit pricey for boaty stuff though.
http://www.flints.co.uk/acatalog/Shackles.html
As mentioned before, for marine stuff it's well worth checking out this site where various connectors were destruction tested..
http://coxengineering.sharepoint.com...onnectors.aspx
I have an unbranded CE marked 12mm stainless dee into 10mm chain with a Rocna 20kg. 25 would be nice if high latitude cruising ever happens and I get rich

Sent from my SGP312 using Tapatalk

[JonJo]

What is the basis for the exclusive and overwhelming support for Crosby gal HT alloy shackles in an anchoring context?

I note they have an enviable range of shackles, but virtually all of them are not really applicable for use for an anchor rode. Their gal alloy shackles, bow and Dee with screw pins are similar if not identical to other, reputable, suppliers but no-one else is ever mentioned.

I have nothing against Crosby but few others are so exclusively mentioned and competition is always healthy. Gal HT alloy shackles appear to be an American product, I have not seen a European manufacturer and maybe Crosby have a good European distribution system (which does not stretch to Australia!) but even Americans only mention Crosby.

Again note - being American their WLL are in short tons not metric tonnes.

Jonathan

[sy_gilana]

I put big-ass galvanised spring washers on my 5/8" shackle's pin either side of the anchor to keep it centered on the pin and it spreads the load.

[JonJo]

Originally Posted by sy_gilana

I put big-ass galvanised spring washers on my 5/8" shackle's pin either side of the anchor to keep it centered on the pin and it spreads the load.

Good idea, few actually keeping the chain centred so a timely post.

Jonathan

[ShipShape]

This isn't directly related to the OPs post, but is relevant to some of the replies:

All About Shackles - Slack Science

Also, I *highly* recommend, "The Complete Book of Anchoring and Mooring" by Earl Hinz.

.

[DoubleWhisky]

Originally Posted by noelex 77

There is a simple modification that can be done that involves drilling a small hole close to the body of the pin so the shackle can still be moused and then cutting off the head of the pin. I did one today and took some photos. Although it is very easy they say a photo is worth a 1000 words.

Disclaimer:
Cotemar does exactly the same thing it's quite possible he posted about this many years ago and gave me the idea.

Thank You for this Noelex

It is funny how simple ideas don't want to simply come on mind

[hpeer]

Old thread I am bumping.

We have a large anchor, the shackle bumps around in the roller a bit. And the pin can catch on the pulpit rail as it is raised or lowered.

Had a standard HT Crosby shackle on it, tolerating the rail interference. But one night in a blow we lost the anchor. I had replaced the mousing in November when we launched. Yet the pun had worked out of the shackle. I know because I found the anchor and the shackle was laying near it minus the pin. My strong belief is that the wire got knocked off the pin while going through the roller guides.

Being in the islands shackle selection was limited, yet I found one in St Barts that works well, does not foul the railing or the roller guides. Works smoothly. But it is stainless.

So my quandary, the tolerate a stainless shackle or to modify a HT shackle as suggested or something else???

In the meantime I have taken to using a soft shackle as a backup.

44’, 20 ton cutter, 125 pound Mantus.

Any thoughts?

[Muaddib1116]

What size chain? Mantus is now selling Duplex 2205 shackles, which are not as strong as Crosby G209A, but have a pretty high rating, and have fewer corrosion concerns than common 316 shackles. They have a hex head on the side, which is a little lower profile, and still have a hole to be wired. The only concern is what testing/proofing do their shackles go through. It's almost definitely not as robust a program as Crosby's, but I have yet to find a report of any Mantus gear failing. The shackles they sell in Duplex are 7/16, 1/2, and 5/8.

[hpeer]

Thanks for that. Will look into the Mantus shackles.

3/8 chain.

[Muaddib1116]

Is that G30 or G40 chain?

https://www.mantusmarine.com/m2-chain-hook/

The bottom of this page has data on their duplex shackles. The 7/16 chain will fit 3/8 chain, but has a lower strength rating than G40 chain. If you want your shackle to be stronger than your chain, you can use their S2 swivel, which uses a 1/2 duplex shackle and has a strength rating above G40 chain. If you have G70 chain, or duplex chain, to make sure the swivel/shackle is not the weakest point in the system, you will have to go up to the S3 swivel that uses the 5/8 shackle. This is what I am doing, but the S3 swivel is quite large, so if you are having problems with shackles clearing your roller, then this is probably not a good option.

[noelex 77]

Originally Posted by hpeer

Any thoughts?

My preference with a galvanised anchor and chain would be a galvanised HT shackle such as the Crosby 209A (but there are similar products from many manufacturers). A Duplex stainless steel shackle can also be a good option.

Whatever you use, make sure it is a name brand with a published load rating, this at least ensures the quality control has been taken seriously. Anchor shackles will experience some side loading that significantly decreases their published strength so it is better to choose a shackle that is stronger than the chain specifications.

If you modify the shackle as per the first post it is unlikely to get caught, and importantly it still allows the pin to be moused. Personally, I think mousing the anchor shackle is the safest option. The mousing can fail, but its integrity is easy to check. There are alternative methods some use Loctite. Unfortunately, once applied it is hard to verify the strength of the glue and there is no visual indication if it does not set or subsequently fails. The third method is to “pean” the end of the pin.

If you are concerned about the mousing you can use a combination of these methods. Undoing a modified shackle may prove difficult if you use anything but mousing but generally if changing the anchor chain (or swapping end for end) it is time to think about replacing the shackle anyway. They are easy to cut.