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dindolino32
climber
san francisco
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Topic Author's Original Post - Jul 4, 2014 - 09:34am PT
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Hi all,
My wife and I were climbing last weekend. She clipped in short from an ascender to the belay loop. Attached her top jug, sat down and BOOM, fell about 6 inches onto the top jug. She was backed up plenty but was surprised to find her bottom jug with a broken biner gate. I attached pics. Mainly this is just a reminder that weird sh#t happens and things can break under small stresses if they are loaded funky. She should have used a locking biner especially when clipping something directly to her belay loop. It torqued funny and probably cross loaded. I think I saw a youtube video of some kid falling when rapping due to a similar scenario. Stay Safe
Dindolino
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RyanD
climber
Squamish
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Probably? Cross loaded?
Definitely cross loaded.
Yikes!
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clinker
Trad climber
Santa Cruz, California
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You need a lighter partner.
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HighTraverse
Trad climber
Bay Area
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A good cautionary tale.
I always clip to ascenders with lockers. The direction of pull is often at off axis angles and there is clutter that can push a gate open without your seeing it.
Glad your wife wasn't seriously hurt.
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dindolino32
climber
san francisco
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Topic Author's Reply - Jul 4, 2014 - 10:06am PT
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Her response, "because my name isn't Locker". LOL. She didn't think about it. I asked her to extrapolate, and there wasn't anything else that she could say. I guess that is the reality of accidents, there isn't a good reason. Luckily she was backed up enough.
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crunch
Social climber
CO
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Strange.
If the biner was simply cross-loaded, that would push the gate hard into its notch. Something would have to break before failure.
In this case, it appears the biner was loaded badly AND the gate was forced/held open, simultaneously.
Crossloading happens frequently while jumaring. When a jumar goes slack, the biner flops around, creating all kinds of sub-optimal loading possibilities. When it's loaded, the biner is pushed against other aiders, jumars, rope, etc, and (with a non-locker) this can easily push and hold the gate open.
I've jumared hundreds of pitches over decades, all kinds of gear used, misused. Whatever was going on, I'd never expect biner failure under bodyweight, or thereabouts.
Maybe, hmmm, maybe your bathroom scale needs replacing? LOL....
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Chiloe
Trad climber
Lee, NH
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This happened to me once in a fall, the biner came unclipped from the rope, and stayed attached to the sling on protection but with its gate now outside of the frame. Result was I fell an extra 20 feet which was very exciting with the ground coming up fast.
But on close inspection, the biner did not really break. Rather, it must have been loaded while the gate was open for some reason, perhaps just chattering in the fall; and with an open gate the biner flexed enough so that the gate sprung outside of the frame. Sounded unlikely to me but that's really the only way it could happen, and the manufacturer (DMM) told me this failure mode was well known and Not Their Fault.
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dindolino32
climber
san francisco
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Topic Author's Reply - Jul 4, 2014 - 10:29am PT
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I agree, the gate had to be bent around the keyed part with the gate open so that it could swing around to the open position. Weird torquing occurred.
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Ed Hartouni
Trad climber
Livermore, CA
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from the top picture it looks like the gate was loaded in a manner such that leaf spring failed, it certainly doesn't look like it is in the right place.
as crunch said, the 'biner design is a "C" which elongates when loaded parallel to the "backbone," as it does this the gate captures on the rail that is at the top of the open side of the "C" and prevents further elongation by increasing the "spring constant" (you have two parallel "springs" the backbone and the gate). This provides greater strength.
Even if the gate is open, however, the 'biner retains a lot of strength, and especially if the load is just the weight of the climber.
Cross loading would be a force perpendicular to the "backbone" of the C, a force on the lower part of the C perpendicular to the screen while holding the upper part of the C fixed. The 'biner flexes and the gate doesn't provide much of a constraint. With enough force you'll break the backbone of the C.
In the case above, the force seems to have been on the gate, with the C fixed somehow, and enough force to deform the 'biner and release the leaf spring. Apparently the aider or daisy of whatever was attaching the climber to the jug released also.
While using a locker would have prevented the release of the aider/daisy, the configuration of the apparent loads was still not a good thing, especially for modern 'biners engineered to provide a maximum strength for a minimum amount of material. It's possible that the particular configuration could have damaged the 'biner (though I think it would be unlikely).
Keeping the 'biners "clean" (not hung up and cross loaded, forces all aligned parallel to the "backbone", etc) is probably a good habit to get into.
glad no one was hurt.
edit see Chiloe's post above
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HighTraverse
Trad climber
Bay Area
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What Chiloe said.
When a 'biner twists adjacent to ropes or hardware or is cross loaded by the rope, the gate can be pushed open inwards, then a continuing torque against something rigid (ascender, rock, bolt hanger) can twist the frame so that the gate can subsequently be pulled open outwards. It's rare and happens in a flash. The tensile strength of the 'biner may not be exceeded so that afterwards there is no apparent sign of the twisting.
It requires first the opening of the gate, then the twisting of the frame and finally a load to pull the gate open.
It's one reason there are locking 'biners.
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jstan
climber
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My first weekend climbing we were treated to a demonstration in which a string of three biners were
exposed to a quick cross loading that caused the middle biner to fall to the ground; completely
detached from both of the other biners. Subsequently when expecting hardware to hold my weight I
adopted the practice of always loading such systems slowly using my arms as an additional backup.
The practice saved me on a number of occasions.
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Jaybro
Social climber
Wolf City, Wyoming
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Not a broken gate,btw. It had a sidewise then forward pressure on it, if you get what I mean.
With old school lite 'biners you were generally able to push the gate around that way with your thumb. I thought all modern binders were immune to that, but I haven't tried in a while. Apparently it just takes more force in just the right vector.
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crunch
Social climber
CO
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Nice posts, Ed Hartouni and High Traverse.
Back in the late 1980s/early 1990s some super lightweight biners (Faders? Latok?) appeared.
Some were so flimsy the gates could be pushed sideways, and forced beyond the notch, by hand.
Biner design improved, adding basic heft to the hinge/gate/notch so that the the gate was far more durable. I've never heard of such problems with the Petzl Spirit line, which seemed to serve as a model for the last couple decades.
But the urge to save weight, and the imperative to come out with "new" models means that maybe the designers have forgotten these lessons, and we've cycled back to where some biners are just a bit too flimsy.
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Jaybro
Social climber
Wolf City, Wyoming
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Edit: dig it, I just did this with my thumb on an economy biner bought at that place across from Nomads
Sometimes the spring pops back, and you would never know the difference. Other times it falls out, turning the crab into a fifi
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HighTraverse
Trad climber
Bay Area
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Jaybro
great experiment.
It might be useful to "Jaybro test" every biner and toss those that fail.
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fear
Ice climber
hartford, ct
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Wow.... Headed up to Jaybro test some biners right now...
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The Call Of K2 Lou
Mountain climber
North Shore, BC
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Dude, what's far more dangerous than a broken carabiner... publishing your wife's weight on the interwebs.
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fear
Ice climber
hartford, ct
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Yeah, at 100 pounds she sure sounds big.
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WBraun
climber
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Why use a stupid biner like that one?
Use a dedicated high strength good locking biner for your jumaring.
Unless you want to look like the people we've picked up at the base after their jumaring failures.
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| Messages 1 - 19 of total 19 in this topic |
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