How strong is a “stabbed” rope?
Scenarios for a “stabbed” rope . . .
Top rope ice climbing, you carelessly swing your tool, and CHUNK, you drive your pick straight into the rope. Whoops!
Walking in a rope team on a glacier. A careless step and you stab the rope with your crampon. Whoops!
If you do either of these, does it completely compromise the strength of your rope?
I've always wondered about this. So, on my latest visit to see my friend Ryan Jenks, the gear-breaking mad scientist genius from HowNOT2.com, we tested it.
The rope we tested was a Beal Opera 8.5 mm, common for glacier travel.
Disclaimer, yes, results will probably be different depending on rope diameter, size of the spike, type of sheath used in the rope, etc. We had a small sample size. This is what we got, don't take it as gospel.
Test 1: Crampon stab through the rope?!
Broke at 11.9 kN. It broke in the knot, and NOT in the “stabbed” part of the rope.
That's close to full strength of the rope.
Click image below to see the short video.
Test 2, pounding a nail multiple times through the rope?!
Broke at 11.1 kN
It broke in the knot, again at pretty much full strength.
Click image below to see the short video.
Test 3: Ridiculously beating on the rope like a manic woodpecker in the same spot with an ice tool ?!
Absurd in real life and would never happen, but sadistically fun to do in the test lab. We do this, so you hopefully never have to.
Broke at 7.6 kN.
Results were yes, majorly compromised but not too catastrophic.
Click image below to see the short video.
Summary: don't make a habit of it, but if you happen to step on your rope with the crampon or spike it once with an axe, it's probably gonna be okay for the rest of your climb. (After that? I'm not gonna make a call on that, the choice is up to you. =^)