You’ve probably heard that you shouldn’t use a handle ascender as your backup device while rappelling or doing other rope access. And, you shouldn’t. But why? Using your ascender as a back up isn’t specifically forbidden in Petzl’s technical notice for their hand ascender (that’s the only one we checked). Nor is it specifically forbidden anywhere else that we could fine.
The reason it’s a bad idea is that it’s not what the device is designed for, and that it’s likely to fail in case of a fall. But, why take our word for it? Have a look at the testing we performed.
The Test Setup
To put hand ascenders to the test we went over to Safety One Training. They just put together a sweet new product testing area and wanted some help breaking it in. We agreed reluctantly because we hate testing products and breaking things. Just kidding of course about the breaking things part. We made record time in getting over to Safety One!
How Much We Love Scientific Testing
How Much We Love Breaking Things For Science
Based on what we’ve seen in the field, this scenario is pretty common. We’ve seen lots of guys using their jumar (or other handle ascender) as a back up device, and pushing it down as far as possible. There are a variety of lanyards in use in these situations, but we think our test with the 4′ fall is representative of many of the cases we’ve seen.
Test One: 2′ Factor One Fall
If you watched the video above, you’ll undoubtedly feel the same way we do… this test was disappointing! By that I mean that we were excited to see the rope get shredded. But, the hand ascender performed surprisingly well. We generated just over 1,400 lbf, but the device held with no significant damage to the rope. The device itself was slightly bent, but still functioning. 1,400 lbf is within ANSI limits so long as it’s on the back D Ring of a proper harness (tsk tsk to those we’ve seen using a handle ascender with a sit harness).
Bottom line: After this fall you’d still be in a position to rescue yourself and descend on your back up line.
Test Two: 4′ Factor Two FallThis test ended as we were expecting. It illustrated the reason why you shouldn’t be using a hand ascender as your backup device. The ascender breaks the sheath of the rope and slides down. In our test it only stopped because we had a stopper knot at the bottom of the rope that made the sheath bunch up. It is likely that without that the test weight would have fallen all the way to the ground.
Bottom line: This test would likely have resulted in a fatal fall. If you were lucky enough to stop and were miraculously uninjured, you wouldn’t be able to descend on your rope to safety. You would need an assisted rescue.
Why Did This Happen?
Ascenders have aggressive teeth, and clamp down on the rope to stop. With enough force they are actually aggressive enough to cut through the sheath of your rope. The sheath of the rope is not connected to the core in most ropes (PMI Extreme Pro being a notable exception). As soon as the sheath is cut, it can slide right off of the core.
I’ll Minimize My Fall Distance
You might be saying to yourself, “Fine, I’ll make sure to keep my ascender high so as to minimize my fall distance. Then there won’t be enough force to damage my rope and I’ll be fine. I’ve always used a hand ascender as my backup, and I always will.”
We get it. You love your equipment, and you’ve used it for a long time without any problems. We’ll just leave you with a few thoughts:
- Ascenders will wear out your rope faster because of their aggressive teeth.
- If OSHA catches you using an ascender as your backup there will be issues.
- There are lots of great back up devices on the market now that work much better than ascenders.
So, please don’t use your ascender as a backup. It’s a bad idea.
Thanks to Safety One for helping us perform this test. Let us know what other tests you’d like to see!