RRC Archives

...a garden gnome up his hungry hole...

THB wrote:

lena_chita wrote:There were no falls or takes on the rope in the 3 days prior to this fall, so you can’t even say that the rope was stretched out from too many subsequent falls in a short period of time, and was thus less dynamic that optimal. I weigh 105 lb. Somebody else can try and calculate the forces, but in terms of climbing falls, this is as light as it gets.

All in all, yes, I agree with you when you say, "this is as light as it gets"... but I bet you still generated somewhere around 3kN-4kN in force on that biner. It doesn't take much to make the force applied to an anchor (and by anchor in this sense, I don't mean like anchors at the top of a route, I mean any piece in between you and the ground that keeps you off the ground) to jump up to around 2kN pretty quickly. Pretty easy to get up to about 5kN-7kN without much rope out and with a hard catch. Pretty hard to get realistic climber scenarios to generate forces more than about 8kN, however... unless you climb on a static rope, don't have a lot of rope out, have a hard catch, weigh more than the average climber, do everything wrong, etc...

The scenario that you laid out in the pictures in your original post seemed to make sense, and in that case, it doesn't take much (around 3kN would be enough I would think) to snap a carabiner. Much like if the nose of a non-key-lock biner is hung up on the bolt-hanger. The biner gets torqued in either of these 2 scenarios and shit breaks, because like has already been said, that's not how the gear is designed to be used.

Glad you are safe. Hopefully we can all learn a little something about this!

THB wrote:

lena_chita wrote:

dustonian wrote:Scary. Had the biner ever been dropped from height as far as you know?

Not as far as I know. These draws belong to my friends/partners, who are very experienced climbers and who take good care of their gear and are not in a habit of randomly dropping it from heights (you know them, they happen to own a cabin in the same place you do, I believe). The draws have been purchased about 1.5-2 years ago, but due to their current location and circumstances they do not do a lot of outside climbing, so the draws have seen only a handful of climbing days since they have been purchased.

A friend of mine did a pretty well designed experiment when he was in grad school for his Master's in Mechanical Engineering. He dropped biners from different heights of the engineering building on to the concrete streets below. Some were dropped from quite high (70ft, maybe higher). He then x-rayed them and found no micro-fractures and tested them in a static pull machine and they all (ALL) broke at above 20kN (most biners are rated to around 20kN).

I'm not saying you should go drop all your climbing gear from the top of routes and still trust it. But he pretty firmly believes after his experiment that micro-fractures in biners after they are dropped is a myth.