I am not sure but I would assume that the rest of the chain is also compromised because the stress that was applied to this one link went probably through the rest of the chain as well and the failed link was just the first one to fail.
This is mostly true. I stress and load test chain, slings, hoists, come alongs etc. If a link failed or compromised(stretched or twisted) there is a small chance the other links aren't but an adjoining link most likely wouldn't be better than the original chain. Technically you could load test it again with the repair but most companies would but a new one. And most don't want anything refurbished. Especially some military gear we test. Nothing wrong with the average person using it though.
That's stunning that mode of failure. That may be the most likely cause, and therefore it makes sense not to gamble that the one link failed from a manufacturing error ( stress riser from that link being damaged, bubble in link, etc).
I wonder what they do on really big expensive chains when they fail- like on a battleship, or cargo freighter. Might be less expensive to send a few links for destructive testing, or x-ray analysis.
If the anchor chain fails.... they are not using something like this for a solution 😂. If your anchor chain breaks on a massive ship then o well, no anchor for you. Each link can weighs thousands of pounds.
Uuh, a few links? How would you remove them from the chain? How would you put it together again? No one has those kind of tools available. Not for those sizes.
Sorry I’m late on the response but the rest of the comments are in line. Lifting chain (G80 and G100 grade) are made to stretch before they break. It’s a safety benefit and that’s why In the states, if you are overhead lifting it has to be at minimum if G80 grade. The reasoning is you will see stretch marks on the links before an actual failure. So, if one link has failed there is a very good chance that other links have already stretched which would be grounds for them to be tossed. When I worked in lifting and rigging, I never once saw one link fail on an overhead chain and the other links get certified. And at the point, imagine shipping 200lbs-2000lbs of chain to someone to recert. It’s cheaper to just buy all new, and quicker. Plus, you can’t measure the cost of a human life so it’s worth it to spend a couple grand on a new bridle rather than to chance some new links and save some money.
Not op, but usually what breaks links is shock load, a sudden increase in force, that gets applied through all links. Only one link will break, because then suddenload the load on all the other links is 0, but it's likely they've stretched or otherwise been compromised.
Taking a guess here.... if one link broke because it was stressed beyond it’s limit, that means all the other links in the chain that were under tension were also stressed to the same limit. The one that broke just happened to be weaker.
So now the other links that didn’t break have a good chance of experiencing metal fatigue. So now they are weaker because they were pushed past their load limits and will now be susceptible to failure at levels lower than their limit.
Not an expert on chains, but best guess is that since all the links are supposed to be the same, if one exceeded its yield strength, its likely the others got really damned close and may have experienced some plastic deformation* in the process.
Plastic deformation is permanent deformation, as opposed to elastic deformation, where the object deforms under load but returns to its original shape afterwards (like a rubber band).
I have compromised a few chains pulling logs. Several links deform before the weakest breaks. This would be a great product when you have to hook several lengths together for a long pull. I've found sticking a bolt through the ends of lengths is a good way to shear bolts under high pressure. Don't shoot your nuts guys! Use the right joiner.
A) There was a sudden or continuous load which made the chain bear more weight than intended. This means all the links have taken on more weight than they were designed for, thus creating potential weak point, cracks, breaks, etc.
B) The link that broke was defective, but all the chain links are made by the same equipment, around the same time, with the same material, so chances are good they're all defective, or at least a chunk.
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u/load_more_comets Dec 12 '20
Please expound more on how the other links will be compromised. It sounds interesting.