How safe...

[muchy_]

...are those chain link things for joining chain together?
I've got hold of some chain at very reasonable cost the only problem is that it is in four lenghts. I've joined it together with some of those links that you bang the little rivet thing to secure them. But has anyone any horror stories of these things coming apart in the middle of night and the boat being dashed onto the rocks etc.....(dramatic licence) ;o)


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[supermalc]

Personally I prefer to cut and reweld the links to join chain.

<hr width=100% size=1>Malcolm.
<A target="_blank" HREF=http://www.angelfire.com/rnb/malcsworld/>http://www.angelfire.com/rnb/malcsworld/</A>
Take a look at my boating pages.

 

[ccscott49]

We use them for joining chains for lifting purposes on the rig, no problems and I`ve never seen one part.

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[Colin24]

We use them extensively in the seismic industry (various sized depending on the application) under very testing conditions, they are to be relied upon and are considered rock solid. I would not hesitate to use them for your purpose.

Colin

<hr width=100% size=1>No boat.

 

[muchy_]

Thanks guys, I can sleep safe in my bunk....

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[wpsalm]

Have used them to extend the chain lengths on a pair of 10 ton chain hoists they both broke...NO WAY... would I use them to extend anchor chain...you,ll just have to put up with the inconvenience of hand lifting that link over your chain gypsy...

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[StephenW]

I've read a number of articles (mainly American) which compare the breaking strain of your type of hammer-on link with a normal shackle and chain.

The general gist of it is that hammer -on types have about 24-30% of the breaking strain of chain, shackles are much more than thisso are to be preferred even though less pretty

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[LadyInBed]

Use shackles, then you won't have to go to the trouble of marking your chain /forums/images/icons/wink.gif

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[Colin24]

I have to say I’m shocked by the statistic quoted re the breaking strain compared with shackles. I’ll not contradict it as I’ve no evidence. But I’ve been using these hammer-loks in a marine environment for over twenty years and in preference to shackles (replacement period is longer)
Failure of these components would be disastrous in terms of lost production and down time, so a lot of faith is put in their ability to hold.
We only use properly sourced certified items and I’m aware of numerous uncertified products available more cheaply. Maybe it is these that others have had a bad experience with.
Apologies, if I’ve given duff advice, it’s simply based on the evidence of my own eyes.

Cheers

Colin


<hr width=100% size=1>No boat.

 

[charles_reed]

Properly fitted

they're satisfactory, but with a lower working load (about 50%) of the normal link.

They are far safer than shackles which, if the pin will fit thro' the link, are about 20% of the link load. (8mm chain = 1000kg, 6mm shackle = 200kg SWL).

The alternative, apart from welding which can be fairly indeterminate, is to use the screw carbine.

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[ccscott49]

I`m afraid you are wrong. There are different types and the good certified ones are very good, giving more than 75%, I guess it depends which ones you buy.

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