Which size and type of chain?

[HopCar]

"Just out of interest, your 1/4 inch G43 with a approx 4t breaking strength - can you buy gal HT shackles to match and fit?

Good point, no. You can do better when you get to 3/8" or bigger but I don't know of a shackle that will match the strength of small G4 chain and fit the link. The shackle will always be a weak point with high strength chains.

Does anyone on this forum know a source of high strength shackles to match the high strength chain?

[JonJo]

Noelex,

Strangely people other than the OP read these threads and rather than give a limited and very focussed reply I hope providing a fuller reply is more useful. If anyone finds it confusing, as you seem to suggest, perhaps they ought not be on this forum, it appears to be very simple to me.

You are obviously not upto speed on Maggi as last I heard they were broadening their horizons and exhibited at the recent Miami show - and you do not invest in that sort of exposure if you cannot supply demand. Delivery might be slow but it might have improved since you bought your chain. Whereas realism is useful - so is being positive and not find fault with everything. It is also useful if you are accurate with your comment.

ISO and DIN 10mm links are different, all the other metric sizes are the same, so 6mm, 8mm 12mm have exactly the same size under both DIN and ISO only the 10mm is at variance and this, as you say, covers all strengths.

Jonathan

[Cheechako]

3/8" shackles always fit my G4 5/16" chain..which helps a little with the strength mismatch. not sure what that means for metric chain. Does a 10mm shackle fit an 8mm chain? I used Forged Wichard SS Shackles on my last two big boats which were rated way beyond the chain. I saw no evidence of corrosion outside the normal.

[JonJo]

A 10mm shackle should fit an 8mm metric chain. There are quite a few gal high tensile shackle makers, G8 strength, but they tend to be American and made to imperial sizes. Some 3/8th shackle pins might not fit metric 10mm links. But I'm not sure about chain links smaller than 5/16th inch, not anything we see at all in Australia - maybe Hopcar can have a look.

In Australia and I believe Europe the strongest shackles for 3/8th inch are only WLL of 1t whereas in America it is common to have 2t WLL 3/8th shackles. I think this might be because they are not used (cannot be used?) for lifting and thus there is no market. This means, if in Europe, you need to source (personally) from America. I'm actually buying some 3/8th inch and 10mm shackles now (Crosby and Witchard) through a UK supplier (Americans have no idea how to sell to individuals offshore) - this is my contact wendy@tecni.eu

Witchard make some good stainless shackles.

Jonathan

[JonJo]

On chain and shackle compatibility

CMP manufacture in their Ningbo (China) factory a range of anchor chain to a range of sizes (under their Titan, or Titon brand), as far as I can make out they make imperial and metric chain to G3 and G4 and/or G43 and also make imperial BBB.

The metric G3 chain is freely available in Oz, but I've actually never heard of anyone selling it anywhere else - but assume it must be available in N America. I see G4 at Aussie boat shows, but not in the chandlers - Australia tends to have a very G3, or Grade L as its called here, focus.

CMP also sell a range of gal, bow shackles, WLL of 1t for their 3/8th inch shackle. With the same branding as the chain.

Strangely - though they sell a G4 chain they do not sell a shackle that matches it. The 3/8th inch 1t shackle fits and is neatly stronger than their 8mm or 5/16th inch G3 chain but is simply too weak for the 5/16rh inch or 8mm chain.

Basically their (CMP) G4 chain must be very difficult to sell here in Oz as unless your are very, and I mean very, persistent it is difficult to use the chain without the shackle (and other gal, bow shackles are the same strength as those from CMP) being grossly under strength.

I am sure Noelex will be able to investigate and identify the solution to this conundrum.

But it does seem to suggest High Tensile shackles are a problem for manufacturers/retailers and us.

Jonathan

[noelex 77]

The best solution with high test chain (especially G7) is to have the manufacturer weld some larger links on the chain (do this on both ends so the chain can be 'end for ended' to even out wear).
It does mean the chain has to be especially ordered in the correct length, as the links are ideally welded before the chain is galvanised. This complicates the ordering, extends the delivery time and not all chandleries are prepared to order these special solutions. With this done a good quality galvanised rated lifting shackle one, or two sizes larger than the chain is a simple solution to the problem (check both the WL and the UTS of the shackle and make sure it is stronger than the chain).

The best high strength shackles are the Crosby "alloy" G8 series, but they can be difficult to get . There are other similar options such as the G8 green pin super shackles which may, or may not be easier to get depending where you are buying.

An alternative that is worth considering, if you are getting desperate finding what you need, is to go for titanium shackles.

Whichard make a 10mm one out of TA6V titanium with a WL of 2160kg (but the break load is only 6,000kg ) For a comparison 10mm G7 has a verily similar SWL of around 2100 kg, but a higher UTS of around 11,000 kg. The Crosby 209A shackle with a also has a WL of 2000kg, but an ultimate load of 9000kg .

I believe the Whichard titanium 10mm version has a 10mm pin. Unlike the galvanised lifting shackles where the pin size is larger than the nominal size. (The nominal 3/8 Crosby 209A has a 11.2mm pin for example ) so it can potentially fit where other 10mm shackles may not. Whichard also make a 6, 8 and 12mm version with WL of 880, 1440 and 2800kg respectively. There are many other manufacturers of titanium shackles.

Whichard HR series of stainless steel shackles are also sometimes used, but there is some debate about their suitability for an anchoring shackle.

Link:Bow

Finally there are some G8 lifting connectors in various different designs like these:
CHAIN CONNECTOR HAMMERLOK
They are very strong and cheap, but both sides have a large eye which will not pass through a small hole like the pin of a shackle will. I have not seen them galvanised, but can be sprayed with cold gal paint.

[HopCar]

Cheechako,
" I used Forged Wichard SS Shackles on my last two big boats which were rated way beyond the chain."

That looks like the answer. Sticking with my 1/4" G4 Chain example, it looks like you could use a Wichard 8mm HR Shackle and the breaking load would be greater than the chain. I think.

Didn't someone say there would be no math on this forum?

[HopCar]

Noelex,
"Whichard HR series of stainless steel shackles are also sometimes used, but there is some debate about their suitability for an anchoring shackle."

I've been using a Wichard stainless bow shackle with the self locking pin for 10+ years. It still looks like new. Of course my shackle is 316L and the HR shackles are a different alloy so it's not really a true test.

[noelex 77]

There is some concern about using SS in anchoring chain /connectors especially when the SS is buries in a low oxygen environment. This is especially true of the 630 SS used in the HR shackles.

Whichard state:
"Although this is dangerous, it is rarely seen in current use, except in cases where martensitic (HR) steel is in total, prolonged immersion."

Part of the debate is whether anchoring constitutes "prolonged immersion"

Andrew Troup (who knows much more about metallurgy than I ever will) stated in a recent post that he considered the HR shackles unsuitable for anchoring. That is enough to make me avoid it. (Sorry I cannot find the post at the moment)

As I indicated it is an area of some debate. The HR shackles are a very attractive option otherwise. They are made by a well respected company reasonably readily available and very strong (stronger than the Whichard titanium version). I anchor 300 days plus a year so I am more concerned about the effects of crevice corrosion etc than most and consequently more conservative. It one of those issues where people need to make up their own mind.

[JonJo]

Originally Posted by HopCar

Cheechako,
" I used Forged Wichard SS Shackles on my last two big boats which were rated way beyond the chain."

That looks like the answer. Sticking with my 1/4" G4 Chain example, it looks like you could use a Wichard 8mm HR Shackle and the breaking load would be greater than the chain. I think.

Didn't someone say there would be no math on this forum?

You will also need another shackle as it is very likely the 8mm Witchard will not fit directly onto the anchor shank, especially if you have gone the Bigger is Better route. Its not a real issue but it would be so neat if you could have only one shackle, as the maths is so much easier when you only need one finger

Jonathan

[Cheechako]

The Wichards I used were not shaped like an anchor shackle, but were long U shaped ones. They had ratings like 20,000+ lbs or something like that. I dont understand the immersion concern, SS cant get oxygen depleted in immersed water... water has a lot of Oxygen in it! I used a big galv shackle on the anchor and the Wichard combined the chain to that.

"The best solution with high test chain (especially G7) is to have the manufacturer weld some larger links on the chain (do this on both ends so the chain can be 'end for ended' to even out wear). "
If you weld heat treated chain dont you just create a soft weak link? It would have to be welded prior to not just galvanizing but also heat treating....

[JonJo]

Cheechako,

You raise an interesting and serious issue. Many who recommend downsizing chain size and upping strength suggest use of bigger links on the chain so as to take a comparably strong shackle and a shackle that also fits the anchor. This latter point becomes more criitical if you follow Bigger is Better (will it ever come back?) as the mantra is small G7 chain but a 2 sized bigger anchor. An 8mm G7 chain would comfortably take a 10mm extra link but this might not be big enough to take a shackle large enough for a 2 times bigger anchor (simply do not know - just a thought).

But the extra links would, as you suggest, need to be added by the chain maker before the chain goes through the Q&T process (which is obviously before galvanising).

The answer would sensibly be that the chain is made by the chain maker, complete with the extra links and the customer pays for the complete chain to be proof tested (2 x WLL), including any larger links at each end.

This then makes the chain more expensive as we now need that extra work, the links added (and I can see this needing a bit of manhandling), the proof testing and this for a non standard length (the length being whatever meets the whim of the customer). There would seem sense for the chain maker to gear up to sell in standard lengths - only.

One does wonder how West Marine customers cope with this issue as WM sell in 'random' lengths and have no facility to add extra links. The suggestion seems to be that people are either using undersize and incompatible strength shackles, or they get the local welder to add the links - which all seems to defeat the object of using the G7 in the first place.

Peter Smith (much quoted by Noelex) and Morgans Cloud et al might advocate G7 but they certainly have obviously never looked at the detail (or if they have, do not explain).

I do know Maggi will add extra and larger links, as that is what Noelex has (which is one reason maybe Noelex had a delay in delivery).

Jonathan

[Sandero]

Disclaimer... I have not read this thread...

Question: Can anyone recount examples of chain failures? I certainly don't think that chain never fails or parts... but when it has failed... what WERE the circumstances of the failure? Rusted chain? Overstressed/undersized? Shackle failure???

Thanks!

[JonJo]

There is a relatively recent thread on CF covering this exact question.

The answer seems to be - no branded chain in reasonable condition has been reported to have failed (which begs the question why G43 of the same size?). In fact there are no reports of branded but old or abused chain failing.

Anchors fail, bending shanks are widely reported. Shackles fail and pins commonly fall out, swivels fail for a whole variety of worrying reasons and anchors drag - but chain goes on for ever.

Not reported on CF but I asked the same question of YBW and had the same lack of reply - except for one new chain that failed at the weld, made in continental Europe (not Italy). The manufacturer accepted they were at fault and quietly replaced the chain.

Proof testing seems the way to go.

Jonathan

[Cheechako]

Bottom line is SOMETHING is going to have to be the weakest link! I suppose if it's the shackle.... it might as well be.... as it's easy to replace and keep an eye on. But unless you can find a shackle at least maybe 90% of the chain strength, why buy G7 chain? the harder the chain the more rust prone it is anyway.. in theory anyway... or is that not correct? (carbon content)
Wichard HR D Shackle 10mm (17-4ph) is 6000 (13200 lb) kg strength
Features

Weight

102 g

Working load

2640 Kg

Breaking load

6000 Kg
I dont really get the discrepancy between the working and ultimate strength on their data. 17-4ph is only about 10% difference betwen ultimate and yield strength in the hardened condition. I guess they down rate it for safety factor and to keep the lawyers happy.
This is the stuff they used to make jet airplane landing gear struts out of I think. Very tough and very strong.