Biner vs. Rack Lever

Recently, on the Vertical Cavers Facebook page, there was a post about breaking a crossloaded biner with a rack eye. There are documented incidents and fatalities. I even tried it a few years ago, unsuccessfully. Of course, this means I had to try it again. This time, I was successful. I actually broke three biners with just my body weight.

Here’s the best one and with some biners that I could not get to break.

Here’s the video of Brian breaking a biner.

Equipment used:
11mm PMI Max-Wear rope
SMC 14″ straight-eye rack with SS, U-shaped bars. (my twisted-eye rack is out on loan)
Petzl Omni (half-round)
Petzl caving harness
QAS (ascender safety)
Me, about 150 pounds.

Carabiners that broke:
Two SMC Locking D Bright, aluminum. These were dirty and probably 17 years old.
One Omega Locking D, aluminum. Also, dirty and old.

Carabiners that didn’t break:
Petzl Attache. The pear shape forced the Omni (half-round) against the gate, counteracting the leverage.
Omega Locking D. Same as the one that broke. This one didn’t.
Mad Rock Ultra-Tech HMS Screw. Again, the pear shape prevented the leverage.
SMC Locking D Bright. Same as the one that broke, except clean.

Conclusion:

This type of failure is rare. Yes, the collars broke, but I still would not call it an equipment problem. It’s more of a technique problem. A simple Rappel Test should prevent this.

The are other ways to prevent this failure. Some locking carabiners use beefier collars. You could use a screwlink instead of a carabiner. This option could potentially cause problems as screwlinks can jam or require a wrench to open. Connecting the rack eye directly to the half-round is possible, but can cause big problems when changing over while using a ropewalker system. Opposite and opposed biners are safer, but also a hassle. My current favorite option is the Black Diamond Gridlock carabiner. It isolates the rack eye away from the gate.

No matter what, do the Rappel Test. Everytime!

One thought on “Biner vs. Rack Lever

  1. Bill Christy

    Another excellent reson to never use a piece of extra, unnecessary gear, thereby increasing the chances of your system failing. It may at times be less convenient, but always put your rack directly on your D-ring, and you will never risk this happening. Problem solved.

    Reply

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