FALL ON ROCK, EQUIPMENT FAILURE
Recently, an REI customer had an accident while rock climbing in which a carabiner broke. (He was not injured, fortunately.) The customer returned the carabiner to the Albuquerque store, and our testing lab examined the carabiner to find out what went wrong. This story explains some of the problems that were discovered—you may want to share the prevention information with your customers in the future.
The customer slipped when he came to the top of a rock pitch. When the force of his fall came on the protection a meter below, he felt only a quick jerk as a carabiner broke, and he plummeted until his next piece of protection held. Instead of a short fall, he took a heart-stopping nine meter fall. He was shaken, but fortunately not seriously injured.
Why did the carabiner break? Similar ones (the carabiner was not an REI one) had tested just fine in the REI Test Lab, a result Quality Control Engineer Cal Magnusson confirmed with further analysis after the accident. So what happened? This is what we learned.
The non-locking carabiner returned to our Albuquerque store was in two pieces. By examining the two parts, seeing how they fit together, and comparing with other cara- biners tested to the point of destruction, Cal concluded that the carabiner s gate was not closed when the total force of the fall came on it.
Closed carabiners are strong, especially in their long direction, usually 4,000 pounds (1800 kg) or more. But open carabiners are much weaker, sometimes holding only 1,000 pounds (450 kg) or less.
Why did the carabiner open? There are three possibilities.
The first is that the carabiner wasn’t properly closed to begin with—the sling or rope was stuck in the gate.
The second possibility is that the carabiner was opened during the fall by the rope or sling twisting over the gate at the moment of impact. This can occur when the protection is at an odd angle, and usually results in the carabiner becoming unclipped.
A third prospect is that the snap of the fall banged the carabiner against the rock, whipping the gate open just as the rope came tight. To see how this can happen, take a carabiner and rap it on your hand. Just when it hits, the gate will come open. If the timing and forces are just so, this can happen when the carabiner takes the fall.
Rock climbers love uncertainty, but not in their carabiners. While we are still uncertain why this one was open, these are some of the lessons to be learned.
Make sure every carabiner is properly closed. Listen for the characteristic “click” as they are placed. Visually inspect them.
Make sure that every anchor system is free of funny twists or turns that could cause abnormal loading on the carabiners. Imagine what a fall would do and construct or modify your set up accordingly.
If you see the possibility of a carabiner banging against the rock, use carabiners with stiff gates. Better still, use two carabiners with gates opposed or a locking carabiner.
Fortunately, carabiner failure is rare; however, it is not unknown. Be careful. And share the information with your customers to be certain they understand what can occur when rock climbing. (Source: Bill Summers article in Compass, January 1990. REI monthly employee publication)