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Posted: Tue May 22, 2007 6:27 pm
by Eric
just attach a haul line through a pulley to a higher bolt, maybe even use two bolts for a 3-to-1 haul system, only the bolt that is being dropped on will have any significant force applied to it. You could even use a wench to haul the weight up each time if you didn't feel like manually doing it.
Posted: Tue May 22, 2007 6:28 pm
by tomdarch
pigsteak wrote:actually, tom's scenario is 90% of the falls taken around here. most folks see the bolt at their waist or knees, freak out and yell "take". this results in a hard short fall onto the bolt, or a nylon burn from grabbing the runner.
I know what you're talking about, but I'd be surprised if those little "take" falls generate higer peak loads than the big whips (but they probably do generate loads that change in direction over the course of the fall more than a straight up whip)
I was thinking of falls where the climber blows the third clip, and you get close to a factor 1 fall without much rope out. Plus, if the belayer runs to keep the climber off the deck, then you'll be decellerating a lot more mass with a less dynamic belay. Still, I'd be surprised if that created more than about 1,000 lbs (edit: OK, maybe 1,500lbs?) of peak force, extrapolating from what Rick's tests are coming up with.
It's all adding up to answering the question of "how strong does a bolt need to be?" It's great that these tests are being done and that Rick is sharing the data. It's pretty amazing that this hasn't already been done a hundred times around the world?!?!