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counterfeitfake

belay device failure

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The reports i've read on belay system failure almost always seem to be a result of operator error, not device failure.

 

But maybe somewhere, sometime?

 

Anyone else?

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Has there ever been an instance of belay device failure?

 

There are lots of them...they usually start out, "I was dropped by a GriGri in a gym....." invariably followed by the description of some dude taking his girlfriend out to belay him and how "I showed her how to do it....blah blah...."

 

Actually, I did read of an instance where a sharp rock wedged into a grigri and chopped a rope in half. I don't know what to attribute that too. Belayer error? Rope failure? Bad luck?

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I saw that scene playout yet again Monday night. Fortunately he didn't fall too hard. Guy was a good sport about it too.

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I wasn't really asking about grigris.

 

This was inspired by listening to the typical speculation about "I dropped my ATC, do I need to buy a new one" where the average response is "Isn't your LIFE worth $25???"

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Consider this:

Someone drops their belay device, and asks the question, "Do I need to buy a new one?" Typical response is, "Isn't your LIFE worth $25?"

 

So most people consider the cost/benefit ratio and "buy the argument" and go buy a new one and retire the old one. So it never gets used again. Ever. So we never learn if it would have failed or not.

 

Now, occasionally, someone will NOT replace the dropped device. Did it eventually fail? Or did he/she just get lucky all these years? We'll never know that either.

 

I know it doesn't exactly answer your question, but I'd posit that that's the way it goes the majority of the time. YMMV.

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I wasn't really asking about grigris.

 

This was inspired by listening to the typical speculation about "I dropped my ATC, do I need to buy a new one" where the average response is "Isn't your LIFE worth $25???"

 

STFUAB is in no way grigri-specific.

 

As far as dropping them? I've dropped and used some, dropped and retired others - it's a 'depends' sort of deal.

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I saw that scene playout yet again Monday night. Fortunately he didn't fall too hard. Guy was a good sport about it too.

 

Yup, sad as hell. Too bad. This isn't my last post and testament, but it will be someplace. ..Hey SOSOB whut time is it?!!!

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My untutored view is: an ATC usually isn't subject to sharp shocks while you're belaying, so it's hard to envision it breaking. On the other hand, aluminum fails catastrophically, so you're not going to see a small crack slowly growing larger each time you catch a fall, the way you might if it was steel.

 

Someone posted a while back a report on tests that were done on caribiners that had been found at the base of walls in Yosemite; the upshot was that dropping a biner a few hundred feet isn't likely to weaken it significantly.

 

Of course, as mentioned above, "Isn't your life worth $25?" So, when in doubt, only use it for belaying, not rappelling!

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Alpine Tom

 

I think your backward on the failure mechanisms for aluminum and steel...steel is typically subject to fracture and aluminum is more maleable (ie not brittle). This is why a dropped carabiner is not super susceptible to failure...basically it does not experience microfracturing...

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My untutored view is: an ATC usually isn't subject to sharp shocks while you're belaying, so it's hard to envision it breaking. On the other hand, aluminum fails catastrophically, so you're not going to see a small crack slowly growing larger each time you catch a fall, the way you might if it was steel.

 

Someone posted a while back a report on tests that were done on caribiners that had been found at the base of walls in Yosemite; the upshot was that dropping a biner a few hundred feet isn't likely to weaken it significantly.

 

Of course, as mentioned above, "Isn't your life worth $25?" So, when in doubt, only use it for belaying, not rappelling!

 

It feels like you read a bunch of other things that made some sense, and kind of puked them back in a weird way that is nonsense.

 

First, why would it be okay to belay with it and not rappel with it?? I'm not climbing with you.

 

I have read many refutations of the "microfractures" theory in aluminum, by metallurgists. I am not one so I can't be sure they're right, but they sounded valid.

 

The "test of stuff at the base of el cap" is kind of a climbing urban legend at this point, I think we should refrain from citing it until someone has the real story.

 

And the "isn't your life worth X" argument has no logical merit, and it is a bottomless hole.

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rumr, I don't think thats exactly true....

the grades of aluminum used for climbing material is NOT brittle...ever look at the mashed lobes on cams, for example? Yeah, they don't really fracture (definition of catastrophic failure) as opposed to deforming...

 

aluminum is weaker than steel but much more ductile...would you like me to drag up some stress vs strain curves and post?

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First, why would it be okay to belay with it and not rappel with it?? I'm not climbing with you.

 

I think that was meant to be sarcastic...

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The "test of stuff at the base of el cap" is kind of a climbing urban legend at this point, I think we should refrain from citing it until someone has the real story.

 

I thought that Black diamond had test some of those old biners but couldn't find it. Found this re: "MICROFRACTURES"

From http://www.onrope1.com/Myth1.htm

 

"Myth #1: You should replace a dropped carabiner because of undetectable "Micro-Fractures".

 

This is the biggest myth we know of, and was probably created by unscrupulous salesmen to get you to buy more carabiners.

 

CarabineerTruth: In a test by Steve Nagode, an engineer at the REI quality

assurance laboratory, 30 carabiner bodies (half ovals, half D’s) were each dropped six times onto a concrete floor from a height of 33 feet. Following the drops, their open-gate strength was measured and compared to 30 control samples from the same production batch and which had not been dropped. The statistical result showed "no loss

of strength.” Inspect any piece of dropped equipment carefully, checking for proper function. Cast metal products are most

vulnerable to damage, fractures and cracks. To my personal knowledge, this happened once to a gray cast metal Jumar ascender in the 1970's. To my extensive knowledge: Drop forged carabiners (and similar gear) have not exhibited this problem.

 

Note: OEM Petzl says: 1mm of wear or gouge is serious enough wear or damage to require replacement.

 

 

-and-

 

BD Worn biner tests:

http://web3.bdel.com/scene/beta/qc_kp_archive.php#040606

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SMC did very similar testing to REI many years back. I can't find the report now, but the pictures were impressive. Majorly tweaked biners were statistically just as strong as the controls.

 

Basically there have been a couple bad choices in alloys over the years resulting in recalls or reduced lifespans (I think the early light-D's, and early double stem camalots are examples). If you can't see a crack, it is likely just fine. Just the same, I'd rather not have second thoughts when I'm cruxing just cuz I cheaped out.

 

Belayers are far more likely to fail than the devices they use.

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i dropped a jumar from the top of the upper town wall last summer - found it in 2 minutes once back ont he ground - been using it regularly for a year now and appears no worse for the wear

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