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Old 05-04-2009, 06:51   #31
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... Don't confuse High Test (what is commonly called HT in the US) with high tensile. US HT is a Grade 40 so easy to galvanise if the bloke doing it knows his game. Real high tensile (a G70 generally) is the one that is virtually impossible to regalv. The G40 is only a high tensile mild steel, it's quite different to a high tensile alloy steel.

I doubt very very much the quality of the US made chains and the EU made chains are much different. We've never seen anything to suggest both aren't pretty much equal apart from the physical sizing and marketing angles. By marketing I mean the US calling a G40 High Test where the rest of the world just calls it a G40.
“G70" is called “Transport” Chain in North America.

NACM Chain Specs:
http://www.nacm.info/Downloads/NACM%20_Welded_Specs.pdf


1/4" Transport Chain (G70)

3150 Pounds Working Load Limit,
Min. 6300# Proof Test, & 12600# Breaking Force

1/4" High Test Chain (G43)

2800# WLL,
Min. 3900# Proof, & 7800# Break

1/4" Proof Coil Chain (G30)
1300# WLL,
Min 2600# Proof, & 5200# Break
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Old 05-04-2009, 07:19   #32
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Speaking of chain, I would like to learn about actual chain failures, where it parted. I would also like to learn about line rode parting incidents which I suspect might be more common.

Have you read of incidents of chain failures?
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Old 05-04-2009, 07:43   #33
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Although Im certain that Chains and Rodes have parted under overload, Ive never encountered such a failure.
Ive seen rare chain Hardware failures (shackles), generally foreseeable due to visually obvious conditions (rust etc).
Ive seen numerous instances of rope failure due to chafe, most commonly of the sawing type.
I have parted a rope with a hydraulic backhoe - an obvious abuse.
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Old 05-04-2009, 07:49   #34
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That's my point as well. I've seen many examples of nylon rodes parting from chafe at moorings, at stem fittings, through "bow" chocks and "fair leads" and coral heads, but know of no chain parting incidents.

I've also seen bent shackle pins, distorted shackles as well.
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Old 05-04-2009, 13:20   #35
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I have parted a rope with a hydraulic backhoe - an obvious abuse.
You would have to think abuse with that one

Thanks Gord. We call G70 Transport here as well but that usually refers to the zinc plated or yellow zinc dichromate (gold coloured and probably poor spelling) so we try to say away from that name a bit when talking anchor chains. All the farmers start using the snig chains from their farms on their anchor winches

I'm in with the Chafe angle with ropes, common as muck. Shackles bending or pulling apart, seen a bit but not a lot. Chains parting not common. They do go but usually from overloading older chains or asian made usually. Seen a few chains not completely gone but had links open up, again usually asian manufactured. People not fixing the bitter end of their anchor rode to the boat and dumping the whole lot over the side, a lot more common that many would think.
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Old 05-04-2009, 14:53   #36
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One of my (many ) pet peeves is bow cleats mounted further than necessary from the fairleads or chocks serving them. The greater the distance between them, the greater the “sawing” action on the rope (rode or dockline) as it stretches under load.

Ideally, the fairlead could be replaced by a cleat, eliminating this point of chafe.

See also:
Cleats & Fairleads

And:
Anti-Chafing Gear
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