Strength of split links - 8mm chain

superheat6k

superheat6k

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My cable is ~70m of 8mm chain, including 35m recently added. In all I have 3 split links - the type made of 2 interlinking 'C' pieces cold rivetted together.

How much strength am I losing at these points ?

is there a better way of joining chain that is also windlass gypsy compliant ?

Boat weight is ~10 tons on a substantial blade anchor of about 20 kg. 8mm is the standard size from the maker, Fairline.
 
In my opinion, these links are s****. Have a look at the Cox Engineering website and look at "moorings". Should be clear.

GL
 
Monique said:
In my opinion, these links are s****. Have a look at the Cox Engineering website and look at "moorings". Should be clear.

GL
Click to expand...

I don't think that's correct. The Crosby C links which the OP is using, I believe, are probably the best way to join chain and pass it over a gypsy. The amount of force needed to peen over those rivets certainly inspired me with confidence.

Richard
 
As RichardS says, high-quality C-links such as Crosby are up to the job, and indeed certified to be so. Their design use is for lifting gear, where there's no mucking about with specifications. On the other hand many (most? all?) of the cheap ones stocked by chandlers most definitely are not. Check out Vyv Cox's website for more information.
 
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Hello Gentlemen,

The breaking point of the Crosby link was 1.04 ton.... the weakest 8mm chain will break at 7.5 tons.... my opinion stands... :-)
 
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Yes, the Crosby ones are good. http://coxengineering.sharepoint.com/Pages/Clinks.aspx Stronger than the chain but they seem to be electroplated rather than hot dipped and you need to keep an eye on their corrosion. New photos at bottom of the page. ACCO may well be OK too if their production problems of a few years ago have been sorted out now.

The ones sold by West Marine look good, also made using hardened and tempered steel. I was going to test some until I found that shipping was going to cost $70 for items costing $5.
 
Monique said:
The breaking point of the Crosby link was 1.04 ton.... the weakest 8mm chain will break at 7.5 tons.... my opinion stands... :-)
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No: 1.04 tonnes was the SWL (safe working load), The 'breaking point' was four times that.

And if I can quote from the same page on Vyv's site: Heat-treated, carbon steel C-links that are marked with a load standard are virtually as strong as the chain which they join.
 
For chain joining, lifting rated, double clevis pins such as this have been recommended by to me by another cruising sailor. Apparently they pass through the gypsy without any problems.

They are available in G7 and the strength is apparently adequate even for G7 chain.
They are not available as galvanised so will need some cold gal treatment with periodic replacement.

I have never used one, so this is second hand info, but it may be an alternative to the C link especially for chain that has to be temporarily attached.

I would be interested in Vyv's opinion.

image.jpg1_zpsjuzqqaa1.jpg
 
noelex said:
For chain joining, lifting rated, double clevis pins such as this have been recommended by to me by another cruising sailor. Apparently they pass through the gypsy without any problems.

They are available in G7 and the strength is apparently adequate even for G7 chain.
They are not available as galvanised so will need some cold gal treatment with periodic replacement.

I have never used one, so this is second hand info, but it may be an alternative to the C link especially for chain that has to be temporarily attached.

I would be interested in Vyv's opinion.

image.jpg1_zpsjuzqqaa1.jpg
Click to expand...

I have one in my spares box but it never occurred to me that it might fit through the gypsy! I will give it a try in a couple of months' time. I'm sure the strength is adequate.
 
I've had no problem with the strength of Crosby joiners, how many anchorers ever get anywhere the SWL of their chain (never mind UTS), but I do have big problems with the corrosion resistance.
I found I had to change them every 3rd season. In the end I've got rid of the last 15m of 8mm chain and replaced it with 50m of Octoplait.
 
vyv_cox said:
I think you have mis-read the page. 1.04 tonnes is the SWL, not the UTS. The measured UTS was 4.5 and 3.8 tonnes. Grade 30 chain is specified to have a minimum break load (UTS) of 3 tonnes
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.... and I thought I'd had it right. Apologies all around... opinion now reset :-)
 
vyv_cox said:
I have one in my spares box but it never occurred to me that it might fit through the gypsy! I will give it a try in a couple of months' time. I'm sure the strength is adequate.
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If an ISO 10mm chain will not fit a DIN 10mm chain gypsy (and vice versa), and the size differences between ISO and DIN are 'small' it is very, very difficult to imagine the illustrated item passing through that same gypsy.

And I am not aware of any 8mm short link, galvanised G30, G40 or G70 metric (or the equivalent imperial) chain with a min break strength of 7.5t

I tried a painted G70 chain hook, it commenced corroding after one night, touching the seabed. I'd stick with reliable 'C' joints.

Jonathan

edit Sorry Monique - our posts crossed:) close edit
 
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J Neeves said:
If an ISO 10mm chain will not fit a DIN 10mm chain gypsy (and vice versa), and the size differences between ISO and DIN are 'small' it is very, very difficult to imagine the illustrated item passing through that same gypsy.
Click to expand...

Before I took the slightest interest in the strength of chain and its fittings I used a collection of three lengths of 8 mm and 5/16" chain joined together with chandlery-bought C-links. Having tested chain I bought a new 60 metre length and dumped the old stuff, but checked it over first. I was surprised to find that one of the C-links was a long-series one, nowhere near the same size as the rest of the chain. It had passed through the windlass countless times without ever causing a glitch. So it just might be that the heavy split-pin type will go through.
 
vyv_cox said:
Before I took the slightest interest in the strength of chain and its fittings I used a collection of three lengths of 8 mm and 5/16" chain joined together with chandlery-bought C-links. Having tested chain I bought a new 60 metre length and dumped the old stuff, but checked it over first. I was surprised to find that one of the C-links was a long-series one, nowhere near the same size as the rest of the chain. It had passed through the windlass countless times without ever causing a glitch. So it just might be that the heavy split-pin type will go through.
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Vyv,

You might be right and I'm interested to see - but not so optimistic.

I know chain is expensive but it secures something of much more value and, personally, I'd rather buy new chain than try to join a number of lengths. I'd rather retire the longest old piece as part of a second rode - and buy anew

Jonathan
 
J Neeves said:
Vyv,

You might be right and I'm interested to see - but not so optimistic.

I know chain is expensive but it secures something of much more value and, personally, I'd rather buy new chain than try to join a number of lengths. I'd rather retire the longest old piece as part of a second rode - and buy anew

Jonathan
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I agree in principle Jonathan. However, I decided to extend our 50m of 10mm chain to 100m and when SWMBO and I had to manhandle 50m chain from chandlers to car and then car to quayside and then quayside to finger berth and finally finger berth to boat, it became self-evident that whereas 50m was, just about, handleable, the full 100m would have been beyond our capabilities.

Of course, we could have found other ways and used outside assistance to manage 100m but I prefer to be self-sufficient wherever possible as you never know when you might have to be. :)

Richard
 
Ah! Richard,

When we bought our new chain we bought it on the basis the vendor, Muir Winches, would deliver it to the yacht. Which they accomplished with a beefy man with a trolley. Once next to the yacht - easy.

The first time we had to move it I very soon discovered I simply could not move it in one lump. It was not that it might damage my back I simply could not move it at all!, but then I'm a 70kg wimp.

Since then of course we have had to take it off, as seldom as possible! We park the dinghy under the trampoline and discharge it into 25l drums and move it, one drum at a time, a couple of metres up the beach, each drum in turn - but we only have 8mm chain.

Jonathan
 
Thanks for all the replies. The long and the short of it, for most respondents is 'yes its OK', and yes they do tend to corrode a bit more than I would like. Might try some galvafroide paint, or perhaps just hammerite - doing these black will draw attention as the chain goes up and down..

I would expect the handling tackle - windlass / cleat will be ripped out not long after the SWL and certainly completely ripped away by UTS.
 
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