Connecting anchor to chain?

[GHA]

Using the correct method for sizing shackles, I hope we are now in agreement that quality stainless steel shackles and quality galvanised shackles, if matched, are roughly similar in strength, at least from any practical perspective.

As the Petersen stainless shackles are metric and a slightly different dimension from the imperial Crosby shackles, there will be anchor chain combinations where one material will just fit and will therefore be the better choice (from a purely strength perspective), but on average there will be little or no strength difference between a quality stainless steel and a quality galvanised shackle.

Hopefully in the future will will see forum threads on anchor shackles without the misleading message that all stainless steel shackles are weak.

:encouragement:


Some data in one place to save people digging in google for it -

Petersen - P is pin diameter
http://www.petersen-stainless.co.uk/lifting/shackles/high-tensile-d-shackles.html

Crosby 209A - B is pin diameter.
https://www.thecrosbygroup.com/cata...pin-anchor-shackles/?view=catalog&language=en

For anchoring it seems reasonable to compare pin diameters, so for 12.7mm a 209A has WLL of 2 2/3 tonnes, Petersen WLL of 2t. As the crosby is 4.5:1 factor of safety it calcs as 12T as does the Petersen with 6:1 FOS. (From Jimmy Green these should fit 10mm lofrans grade 40 chain. - "Maximum Pin Diameter = 13mm = the largest pin which will fit comfortably in the end link of 10mm DIN766 or ISO chain.")

And Crosby D -

A very quick look at Jimmy Green suggests you 209A only go small enough for 10mm chain (only data for 8mm - 10mm there, not 9mm)

Another possible factor is the embossing on the crosby causing a possible but hard to quantify risk of jamming as mentioned above when articulating as the tide changes, though you could grind that mostly off)

 

[Neeves]

Using the correct method for sizing shackles, I hope we are now in agreement that quality stainless steel shackles and quality galvanised shackles, if matched, are roughly similar in strength, at least from any practical perspective.

As the Petersen stainless shackles are metric and a slightly different dimension from the imperial Crosby shackles, there will be anchor chain combinations where one material will just fit and will therefore be the better choice (from a purely strength perspective), but on average there will be little or no strength difference between a quality stainless steel and a quality galvanised shackle. There are other manufacturers of quality galvanised and stainless steel shackles and some of these come in alternative sizes.

Hopefully in the future will will see forum threads on anchor shackles without the misleading message that all stainless steel shackles are weak.

A useful post,

I look at shackles on rodes and I have never seen a Petersen shackle nor a Cromox shackle, UK, USA, Mediterranean, Australia (and there is a distributor, I think, in Brisbane who sell both Cromox and Petersen). I have seen Witchard shackle (though whether HT or not, I could not determine). I do see lot of unmarked stainless shackles and plenty of unembossed galvanised shackles.

It would be interesting to hear responses of those who use stainless - and who use 'named' products. I wonder how many have put their hands in their pocket and bought Cromox or Petersen.

There is this belief that because stainless does not rust it must be strong. There is also the belief that embossed galvanised shackles are all the same (West Marine's embossed galvanised shackles also bend like spaghetti).

It is important to specify which, shackles, are reputable - as there are many that have never been tested.

You mention that:

There are other manufacturers of quality galvanised and stainless steel shackles and some of these come in alternative sizes.

Can you name them and they can be included in future threads? Personally I only know of Campbell and Crosby for ''our' size of galvanised shackle and Petersen, Cromox and Witchard for stainless, of 'our' size.

One other factor - all of these size are nominal, the size of the clevis pin, the hole in the chain and particularly the slot, or hole, in the shank. The best way to match is to take a link of chain and the anchor (or check if the chandler has 'your' anchor on the shelf - and size on the spot. It is not only the size of the hole of the shank but thickness of the shank that determines how easily the shackle rotates.

Jonathan

 

[noelex]

You mention that:

There are other manufacturers of quality galvanised and stainless steel shackles and some of these come in alternative sizes.

Can you name them and they can be included in future threads? Personally I only know of Campbell and Crosby for ''our' size of galvanised shackle and Petersen, Cromox and Witchard for stainless, of 'our' size.

Jonathan

I would need to put on my thinking cap for that one. A few manufacturers spring to mind that are not included on your list, but I think there are many more:


Cmp -Titan brand
Van Beest-Green pin
Harken
Titan (titanium)
Gloma Nautica
Gunnebo

 

[Neeves]

If these were made to specification, the last batch I tested, 2 year ago, did not, are probably the best around.

https://www.peerlesschain.com/products/Peer-Lift-Alloy-Screw-Pin-Anchor-Shackles/

I will try to get some more samples.

I don't know where to buy them in Europe, but Kito (Peerless' parent) has a distribution centre in Germany from where they distribute their short link metric anchor chain (a member of this forum bought some)

Again, sadly, I don't know how to source them from the UK but these are some of the best, better than Crosby.

http://www.campbellchainandfittings...hackle-screw-pin-forged-alloy-galvanized.html

CMP Titan are not as good as Crosby, Campbell, or Peerless, Van Beest do not make small sizes of HT gal shackles (neither do Columbus Mackinnon) so neither are a source for us. I have never seen a Harken shackle that would be suitable, most people have shallow pockets - which rules out titanium, Gunnebo - I have never seen HT gal shackles in their programme.

The list, exclude dreams, is

Crosby gal
Campbell gal
Peerless gal
CMP gal, not as good as the 3 above
Peteresen stainless
Witchard stainless
Cromox stainless, only D

The easiest and cheapest to source will be CMP, followed mail order from Tecni with Crosby. CMP come in sizes smaller than 3/8th" (as do Peerless).

Most gal shackles in chandlers and hardware stores now come from China, some are excellent, some are rubbish. Most, almost without exception, stainless shackles in chandlers (and hardware stores) are 316 and will bend like spaghetti (when you retrieve a well set NG anchor in a chop - the loads are sufficient to bend a 316 shackle). Buy unbranded shackles at your peril.

If anyone find a manufacturer of a gal 3/8th" bow shackle with a WLL of 2t, outside the above list - I would be interested and would source and test. I have not found anyone yet (and as I mention some on the list are questionable and CMP does not make a 3/8th" to a 2t WLL).

Jonathan

Edit

I could not find the Titan Black Pin shackle on the website, only their brown (orange?, used to be yellow) pin shackles. They may have discontinued their Black Pin shackles, though chandlers may still hold old stock. Their 3/8th" Black Pin shackle was WLL of 2t, they downgraded to, I recall 1.8t? - now I cannot find them at all - on the CMP Titan website (I'm not that patient!).

http://titanmarineproducts.com/sites/default/files/downloads/Shackles Specifications.pdf

CMP Yellow Pin shackles are a standard Grade A, (3/8th" WLL 2t vs Grade B 3/8th" WLL 2t) they are good quality. Grade A are the one you find in mot retail outlets


Gunnebo only make Grade A shackles to a standard bow design

http://www.gunneboindustries.com/Li...kles/Gunnebo-Lifting-Standard-Shackle-No-854/

Close edit

 

[Neeves]

GHA's Post #41 above

Very useful,

Hidden in the detail GHA make the comment, rightly, that a European 8mm (and 6mm) metric chain will not accept any of the clevis pin on the available Grade B (Crosby G209A nor Campbell Orange pin HT) shackles. The hole in the link is too narrow. It is not until you can get to 10mm chain that you can fit a shackle, as is, and then it will be undersized for strength (or you will not get the full strength benefits).

This confounds the advice you could, and can, use a shackle the next size up from your chain. The advice is for a 8mm chain that you should (and can) use a 3/8th" shackle. This works in America as 5/16th" will accept a 3/8th" shackle and works in Australia (where our metric chain is different to European metric chain). It does NOT work in Europe.

I think GHA quote from Jimmy Green of Lofrans G40 chain and I've just checked with Maggi A4 chain. The 3/8th" clevis pin, the clevis pin from a 3/8th" shackle, will not fit an 8mm European metric chain. I'm actually not sure that the smallest Petersen shackle's clevis pin (sized at 10mm pin) will fit all 8mm metric chain - it needs checking (as the sizes are nominal and the weld might also impinge). A 10mm stainless clevis looks a very tight fit for the Maggi A4 unless its a skinny 10mm and thin gal (and the weld of the link might still impinge)

This has been discussed previously and Vyv has suggested squeezing the link in a vice, lengthways, to expand the hole, widthways, of the last (or first) link - it only needs an extra 0.5mm. Vyv has previously mentioned it will not damage the strength of the chain, but the vice you will need to squeeze the link may damage the galvanising, squeeze with a leather pad on each face plate, perhaps.

Alternatives are fiddly - I have been using appropriately sized G100 Omega link as an end link (enlarged link). These are available from most of the lifting companies, Gunnebo, Van Beest (their Excel range) etc. This works well - they come in metric sizes from 6mm and up. They are not galvanised (and I have not seen them galvanised) but it is not difficult and possibly Geoff could be persuaded to add them to his portfolio. I have mine galvanised here in Oz (and for people who have followed what I have done I suggest adding in a good few spares).

Adding the necessary component to a portfolio of ground tackle product to allow an owner the opportunity to simply join chain to anchor (compatible for size and strength) does not appear a silly concept (I'd see it as a marketing edge). Omega links are made in HT Duplex stainless, but this will incur even more expense . The ungalvanised G100 Omega link will degrade to a G70 as a result of the galvanising - but as most are using G40 or G30 that is not an issue - and would be ideal for G70 chain.

Squeezing the link is the easiest option.

For those cruising distant shores, or plans to cruise distant shores - it merits considering that you need spares, finding even a simple shackle to fit your chain will not necessarily be easy and finding a chain to fit your metric gypsy - very difficult and expensive (metric Oz and NZ are not guaranteed offering the answer!).

This answers a question of why many use 2 shackles, use a swivel, use one small and one large shackle - its pretty simple - most of the components are simply incompatible and owners have to fudge. The supplier who recognises the issue might develop an edge.

Jonathan

 

[vyv_cox]

Just a comment on the Wichard HT (haute tension) shackles. They were always 17/4PH in the past, a precipitation hardening stainless steel. When I bought my countersunk hex key 10 mm ones many years ago they were made in this alloy but the last time I checked the Wichard catalogue this particular style was only available in 316. The low yield stress of 316 could be a problem if subjected to very high loads, although having seen many being tested in tensile machines I find it difficult to imagine that they could be generated in the real anchoring world.

 

[Dutch01527]

I have two anchors, a 10kg delta and FX16 fortress and two rodes, 30m 8mm chain and 50m nylon and 10m 8mm chain and 50m nylon.

I wanted a way of being able to mix and match easily to suit the circumstances and conditions i.e. quick swop over of chain to anchor connection. I stumbled across aircraft / military snap shackles at a local market.

I have one on the end of each chain and can snap anchors on and off in seconds. Safe working load is greater than the chain and the locking mechanism is 100% safe in my opinion. I was told that they use these to parachute land rovers of transport planes. The nuts in the image are there to centralise the load pull direction. I will keep an eye open for any corrosion where the alloy touches the stainless nut or galvanised anchor shackle.

 

[noelex]

The list, exclude dreams, is

Crosby gal
Campbell gal
Peerless gal
CMP gal, not as good as the 3 above
Peteresen stainless
Witchard stainless
Cromox stainless, only D

If you want a broad list to suit many boats, personally I would not exclude some of the manufacturers you have left out.

I have never seen a Harken shackle that would be suitable

The Harken HR shackles would be suitable for some applications. Their stainless steel 10mm HR shackle has a very high working load of 3720Kg but they use a 2:1 safety factor so the ultimate load is less impressive 7450 kg. One big advantage of the Harken and the Whichard HR shackles is they have the same pin diameter as the body diameter, so the working load is exceptional for a shackle with a 10mm pin and the ultimate load is still very good.

Van Beest do not make small sizes of HT gal shackles (neither do Columbus Mackinnon) so neither are a source for us.

Van Beest make a very good 1/2 inch Hi test shackle (their Super Shackle), which would be suitable for many larger yachts. From memory it is slightly stronger than the Crosby 209A (although small differences have little practical consequences) and importantly comes with with a bolt and split pin design, which for an anchor shackle can be a better option than the tradition pin. Crosby make a similar design that I think would also be excellent, but the Van Beest is (slightly) stronger.

most people have shallow pockets - which rules out titanium

Titanium itself is not enormously more expensive than some of the exotic stainless steels. While not cheap, titanium shackles are available from several companies at the type of cost that would not be out of the question for some boat owners if they solve a problem, especially given their extreme corrosion resistance and consequent long life.

Some research needs to done on the testing procedures and quality control before purchasing, but for example Titan offer a 13/32" (10mm) model for $58.62. There are several other companies offering similar products. They are at least worth a look if you want to avoid galvanised shackles.

 

[Neeves]

Other than using stainless chain - I cannot think of why you would want to avoid using a gal shackle - maybe you can elaborate, at 20% of the cot of titanium they look a positive bargain.

Jonathan

 

[noelex]

Other than using stainless chain - I cannot think of why you would want to avoid using a gal shackle - maybe you can elaborate

Using a stainless steel anchor and/or chain is a common incentive, but there are other reasons to use a stainless steel shackle.

Some people prefer, or even need, a recessed pin shackle and this style of shackle is reasonably readily available in stainless steel, but not in a hi-test galvanised material (at least I cannot think of a galvanised model that fits this description).

Likewise, if you want a hi-test shackle but the pin size is a limitation, hi-test stainless shackles are available with a pin size that is identical to the body size, whereas all the hi-test galvanised shackles all have a larger pin.

If you use an anchor with a slot like the rock slot on the Manson Supreme, a stainless steel shackle is better (most would say essential), as it will slide along the slot with less friction, especially with a side force. If the shackle becomes jammed at the fluke end, the anchor will not function. Note: If using the Manson Supreme I would strongly recommend using the conventional attachment point for overnight anchoring, and if you always use this attachment point a galvanised shackle is fine, but if you occasionally use the slot, a stainless shackle is better.

The reduced friction of a stainless shackle can also help in those cases where the shackle has a tendency to jam or lock in place when a side load is experienced. This is a rare, but occasionally serious problem. It can significantly affect the anchor’s performance. Usually switching to an alternative design, or alternative size of shackle will eliminate the chance of it locking up like this, but in recalcitrant cases the slippery nature of stainless steel compared to a rough galvanised finish is often better.

Lastly, of course is the advantage that stainless shackles rust much less as they age compared to galvanised models, although you should still inspect a stainless steel shackle regularly as corrosion can occur.

Personally, I use a galvanised shackle. However, if you do want a stainless steel shackle, strength should not be a reason why you cannot use this material, as long as you use a quality shackle (and this applies equally to galvanised models). There will be cases where a particular chain diameter and anchor slot will result in one material becoming available in a shackle size that enables a larger and stronger model to be used, but these are exceptions. Usually quality stainless steel or galvanised shackles can be used with equal strength (at least from a practical point of view).

In my view, anchor threads would be more helpful, especially to people starting out, if we could eliminate some of these silly and inaccurate statements that keep cropping up over and over again. It has taken some effort , but dispelling the myth that all stainless steel shackles are too weak to contemplate in an anchor system is a start. Next we need to work on the myths: “It is the chain not the anchor that holds the boat” and “A small anchor has the same ultimate holding power as a larger anchor of the same design”.

I live in hope .

 

[Neeves]

In my view, anchor threads would be more helpful, especially to people starting out, if we could eliminate some of these silly and inaccurate statements that keep cropping up over and over again. It has taken some effort , but dispelling the myth that all stainless steel shackles are too weak to contemplate in an anchor system is a start. Next we need to work on the myths: “It is the chain not the anchor that holds the boat” and “A small anchor has the same ultimate holding power as a larger anchor of the same design”.

I live in hope .

Hope springs eternal - you might need to wait some time. Your first keeps appearing 'that it is the chain....' I frankly do not understand the logic that allows anyone to believe this - and as long as the concept does not gain momentum I cannot be bothered - as I cannot understand the thinking, so cannot think how to counter it.

Similarly your second myth - A small anchor of course, of the same design, has a lower holding capacity - that has never been debated. What is debated is 'that a big anchor holds better than a smaller one - for a given yacht, given seabeds, given rode etc - as long as the smaller one is working within its ultimate holding capacity. As in most seabed a small anchor's capacity (small in your eyes - usually small means the size recommended by the manufacturer) is commonly 2 - 3 times the WLL of the chain, assuming recommended chain and anchor, then exceeding its capacity looks - very - unlikely, In some seabeds the UTS of the small anchor will be exceeded, thin mud is an example, but maybe dense weed - then you are better with a different anchor (or find a new location) - as a bigger one might be no better.

I accept that people 'feel' safer with a big anchor - but I have yet to hear of say a Rocna of the recommended size dragging when the yacht next door (similar ground tackle, similar yacht, with an oversized Rocna) remained secure. In fact stories of NG anchors dragging are a bit like hens teeth - no quite as rare - but pretty unusual - and commonly due to factors not determined by size (supermarket trolleys being an extreme example).

So come up with statistically sound data, not gut feel, that a bigger anchor is more secure, same yacht,, same seabed, same rode - and I will reconsider (my position that the sizes recommended by the manufacturers are about, or exactly, right).

In the meantime - as I have seen no statistically sound data - we can agree to disagree as debating the concept makes no progress - and I am sure you must have better thing to do!

Jonathan

 

[thinwater]

I have a simpler way of looking at this.

Every 3-7 years (depending on use) I cut off the shackles and the last few links from each end of the chain. If there was a swivel I would replace that, since I have seen cracks. I then rotate end-for-end. I install fresh rated shackles and re-splice the rope to the chain at the other end. In this way the minutia of gear selection is probably mute, so long as it is moused or thread-locked and of good quality. I really don't care if the shackle is seized, since I will cut it off.

(I would not trust a stainless shackle longer than a galvinized shackle. Corrosion and cracking are about equal risks over time.)

(I splice a rope to the end of the chain even if using all-chain. In this way the pendant will feed up through the windlass, from the bottom of the locker, so that it can be easily cut on deck.)

 

[noelex]

That is much too sensible a post for an anchor thread, Thinwater .

I do very much the same thing. I do try to use the best shackles because why not?, but with G4 chain it makes little or no practical difference.