Failure of Locking Carabiner under Body Weight


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Paul Martzen

Trad climber
Topic Author's Original Post - Feb 20, 2015 - 10:57am PT

This photo was posted on a canyoneeering forum. I told the owner to contact Petzl. His brief account is:
Second to last rap on Monkeyface with lock gate (no misuse) and semi-soft start, very likely shifted on it's side (gate towards me not out); my rain coat may have covered my view of it the rest of the way, otherwise I would have noticed. Nearing the bottom and with the last step, a very loud low-base boom broke the carabiner. It was was off my harness and still attached to the rope. Found three pieces on forest floor but no pin.

My speculation is that his harness somehow opened the gate and loaded it sidways. The leverage broke the gate at the pin. But how you could open the gate and load it sideways while on rappel is very puzzling. Anyone know of studies of this sort of failure?

If there are insightful replies, I will copy them to this first post, so others don't have to search as much.
Greg Barnes

Feb 20, 2015 - 11:09am PT
Counterfeit biner?

Social climber
Feb 20, 2015 - 11:30am PT

I wonder if the pin was not finished properly and was working itself loose? If it were partway out then I could see there might be enough leverage to break the last bit of the gate like that.

Other scenario might be an existing hairline fracture in the aluminum? But then the pin would surely not be lost, it'd still be in its hole?

There may be more info that's not known or not presented here.

Ice climber
hartford, ct
Feb 20, 2015 - 11:37am PT
I've tortured cross-loaded locking biners like that with a truck just to see... I've only succeeded in breaking a few like that and those were under far more than body weight when they broke.

I see no way to do that with a rappel.

He did mention things were obscured under his jacket... Perhaps some kind of wild twisting going on. Did he ever post a picture of his usual rap setup?

Trad climber
Boulder, CO
Feb 20, 2015 - 12:14pm PT
Is this the type of biner where the sleeve screws down towards the gate hinge, or screws upwards to the nose of the biner?

If it locks at the gate hinge, could the contact point between the sleeve and biner somehow create a fulcrum near the fracture point, with the gate forming a lever with a lot of mechanical advantage?

Seems unlikely, I would expect deformation somewhere before catastrophic failure. I'm just brainstorming here.

But based upon the red indicator near the nose, it looks like it's the more conventional design where the sleeve screws upwards towards the nose.

I've seen videos of the testing rigs where they individually pull test every biner, and destructively test samples. YouTube "How carabiners are made". Anybody know what sort of QC goes into the gates and pins?
Clint Cummins

Trad climber
SF Bay area, CA
Feb 20, 2015 - 12:18pm PT
Did he ever post a picture of his usual rap setup?
I wonder what his friction device was:
 Munter hitch on this biner
 brake bar?
 Petzl Stop?

A friction device with a narrow hole that the biner clips could possibly get onto the gate and exert the torque.
But it would probably need to be in that position when the rap starts.

Or maybe the way he attached the locking biner to his harness could do this.
 belay loop?
 directly to harness straps bypassing belay loop?
 sling which joins harness and biner?

Something (the rope?) has to engage the locking ring to twist it down to the open position (assuming he is correct in saying it was locked at the start).

Trad climber
Boulder, CO
Feb 20, 2015 - 12:25pm PT
Was the gate locked at the time of failure? The exposed red indicator would suggest that it wasn't, but it might have been altered before the picture was taken.

Mike Bolte

Trad climber
Planet Earth
Feb 20, 2015 - 12:26pm PT
this is one scary post

4 Corners Area
Feb 20, 2015 - 12:30pm PT
The only way I can see that happening is if the gate itself was loaded while it was open. This is totally possible if the biner is already being cross-loaded (with the belay loop across the gate). It would be even easier if it was a quicklock carabiner (I'm not sure from the photo, but I don't think it was.)

Mountain climber
The Other Monrovia- CA
Feb 20, 2015 - 12:38pm PT
One takeaway for me is where he mentions his jacket covering up his setup.
No matter how much clothing I wear I ALWAYS make sure I can see my setup -
all the time. Besides, if your clothing is covering your setup then it is
only a matter of time before it gets caught.

Trad climber
Feb 20, 2015 - 12:40pm PT
So that biner says 6K with an open biner. How much force DOES a simple body weight rappel put on a piece? Of course way, way, lower than six, I'd think. Just wondering.

It would be interesting to find out if it was a counterfeit.... And as a reminder - don't buy yer frigging climbing gear from Joe Nobody on EBay selling mass amounts of brand new gear at below a bargain prices!

On this ride, I'm cptn; My pals call me Shackleton
Feb 20, 2015 - 12:41pm PT
why-o-why did I open this thread?

4 Corners Area
Feb 20, 2015 - 12:54pm PT
So that biner says 6K with an open biner

That is being loaded the long way. I'm saying he could have weighted the open gate, so the only support it had was the pin.

I bet there are many climbers who could break the open gate off a biner with their bare hands! (I'm gonna go try it)

Social climber
Feb 20, 2015 - 01:11pm PT
Great comments. Rapping, it would be almost impossible to cover up the rappel device. The device has to be high up above clothes just because it's what one is hanging from.

It appears to be a Petzl Attache. Burly carabiners.

I still think the 2 scenarios are:

a defective pin that was coming loose.

Or, if a grigri was involved, the grigri could have been pushed around to the hinge and thus put a lot of nasty torque on the gate, It can actually catch on the peened, mushroomed bit of the pin (just tried this with grigri and Petzl Attache). You'd have to be pretty inattentive to not see this happen.

Trad climber
Poughkeepsie, NY
Feb 20, 2015 - 01:21pm PT
This type of danger has been known for a good fifteen years and has resulted in at least one fatality. The problem is that certain devices can, in some circumstances, get into a position (and there are at least two such positions) to lever open a locking carabiner gate, and no more than body weight is needed. One of the fatal configurations is more likely to happen if the locking biner is clipped through the harness tie-in points rather than the belay loop.

The documentation I know of refers to figure-eight rappel devices and is at Pictures of two possibly bad configurations are included.
Clint Cummins

Trad climber
SF Bay area, CA
Feb 20, 2015 - 01:21pm PT
Included in scenario one - possible counterfeit Petzl Attache biner (as Greg posted).
These do exist.

Trad climber
Norwalk, CT
Feb 20, 2015 - 03:24pm PT
Absolutely horrible if somehow these fake biners have made it into circulation.

Bravecowboy you abandoned your son
pick up the phone he wants to talk to you
your obviously posting online
grow a pair and call

Does the Supertopo drama ever stop?
Gnome Ofthe Diabase

Out Of Bed
Feb 20, 2015 - 03:25pm PT
Ouch to the search for the (notso) brave one

and as the happiest goyle said, >>>+1

that is as Clint and rgold point out not the 1st but it looks like all my newest lockers.

Gonna go and have a look,
I really can't say but it seems that the older Gri Gri's hole was prone to cross loading the petzel (or a fake??) in bad ways.
Every one has said it in so many ways,Yikes,
This is another reason that Tying in and creating redundancy with a waist loop (chack bag belt of webbing tied with a water knot and clipt to a back up (prussic,Klimbhiest)On long raps. with two 70 meter long skinny ropes is a good idea( if not a pain in the a.)
Paul Martzen

Trad climber
Topic Author's Reply - Feb 20, 2015 - 03:46pm PT
Thank you for the really excellent replies and especially for the links. I had not gone searching for such studies yet. I am in contact with the unfortunate yet very lucky fellow and will get more information about his set up. Prior to my writing to him, he assumed that he somehow put 7kN of force on the carabiner while rappelling. He had been making some comments that I did not take seriously until he posted the photo. Holy Crap!!!! I have been encouraging and interrogating him since.

I will forward the links to him and report further details here.
Greg Barnes

Feb 20, 2015 - 04:27pm PT
Ask him where exactly he bought the carabiner. If it's a random cheapo internet source, it'd be more likely to be a knock-off.
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