Dog Chain Stress Test

auralpaz

Member
Hello all,
Does anyone know of a video that shows dog chain under a stress test? I'm trying to prove a point that it isn't suited for certain applications.

-Matt
 

chausman

Chase
Fight Leukemia
You shouldn't use any hardware that isn't rated for overhead lifting. That said, what is it being used for?
 

gafftapegreenia

CBMod
CB Mods
You shouldn't use any hardware that isn't rated for overhead lifting. That said, what is it being used for?

I think he knows that and he's looking for some nice graphic video to show his higher ups.

Too many people don't care about using "rated" chain, and rather will keep using something if it's "worked so far".
 

derekleffew

Resident Curmudgeon
Senior Team
Premium Member
Does anyone know of a video that shows dog chain under a stress test? I'm trying to prove a point that it isn't suited for certain applications.
Perhaps send a sample to Delbert ( Load Lab Home Page ) and he'll test it for you? However, what will the results really tell you? A representative sample breaks at x pounds of force. Does this then mean that the chain can be safely used to support x/5, x/7, x/10 (whatever safety factor you want to apply) pounds?

See also Test results Not for Overhead Lifting 2/14/2009 .
 

kicknargel

Well-Known Member

MNicolai

Well-Known Member
Premium Member
Fight Leukemia
What I find most interesting about this is that two samples of a quick link failed at very different loads (2415# and 4850#). Which to me says that even if the non-rated hardware seems to be able to take the load, you can't trust the quality control. There may be a bad apple in the bunch.

Quick-links are rated hardware -- they're just rated for a different purpose. Worth noting that the lower failure was a factor of 3.92:1. Just a little less than general 4:1 design factor used for chain. Judging from the photo of the sample, I'd venture a guess that the test was performed along the narrower axis that a properly used rapid link shouldn't ever be used in anyway.

The link here is more telling, explaining what it takes to destroy a rapid link at lower thresholds (by shock-loading it and pulling it from the side).

Therein lies the value of rated hardware. It has a design factor such that normal use should never compromise it and even abnormal (read: reckless, improper) uses still allow you a large chunk of room for error.

There's never a better substitute for knowing what you're doing, but rated hardware is forgiving in that accidental design/implementation/usage errors should not turn catastrophic.
 

MPowers

Well-Known Member
You shouldn't use any hardware that isn't rated for overhead lifting. That said, what is it being used for?

Careful with blanket statements. For example, remember, the most common chain used for batten trim chains, 1/4" proof coil G30, approved by OSHA for the use, IS NOT rated for "overhead lifting".

One of the problems with anything being used in a manner for which it is not intended, or pushing the limits, or working with "unknown" capacity, is that failure is highly unpredictable, both in initial strength and with sudden failure at a loading or force that worked before.

To do a meaningful "test" would require a meaningful number of "breaks" with several different sources of the twist-link chain we all lovingly call "Dog-Chain".

As for a test proving what the OP wants, "be careful what you wish for ". A test that shows your higher-ups intended use may not fail.......this time. What you really want, even in a small sample, is unpredictability. Highly different results between several samples.

What is the use someone wants to use the twist-link chain??
 

mstaylor

Well-Known Member
Departed Member
Careful with blanket statements. For example, remember, the most common chain used for batten trim chains, 1/4" proof coil G30, approved by OSHA for the use, IS NOT rated for "overhead lifting".

One of the problems with anything being used in a manner for which it is not intended, or pushing the limits, or working with "unknown" capacity, is that failure is highly unpredictable, both in initial strength and with sudden failure at a loading or force that worked before.

To do a meaningful "test" would require a meaningful number of "breaks" with several different sources of the twist-link chain we all lovingly call "Dog-Chain".

As for a test proving what the OP wants, "be careful what you wish for ". A test that shows your higher-ups intended use may not fail.......this time. What you really want, even in a small sample, is unpredictability. Highly different results between several samples.

What is the use someone wants to use the twist-link chain??
It's not a matter of wanting to use it, it's a matter of wanting to remove. Without giving a location, it is in the pictures of bad rigging on a well known rigging company's site. I am familar with the location and it needs to go. I'm not sure that you really want a known breaking point because it could be turned around saying the weight on it is less than the breaking point. As noted above inconsistancy is better ammo than an actual number. The other problem is what it is attached to above. That's shakier than the chain.
 

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