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kyhangdog
Nov 9, 2004, 4:50 PM
Post #1 of 2
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Registered: Oct 4, 2001
Posts: 480
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Anyone know the effects of repetetively stressing a bolt/hangar setup? We've all seen groups of climbers fall at the crux of a route repeatedly. On a route that sees a lot of traffic, and consequently, a lot of falls, how long should a bolt last before it's replaced?
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miklaw
Nov 9, 2004, 5:17 PM
Post #2 of 2
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Registered: Jan 13, 2004
Posts: 99
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3 effects:- In soft rock the rock eventually craters and the bolt loosens or fails, that's why expansion bolts and hangers aren't good in soft rock (such as Blue Mountains Australia sandstone, where some 2000+ bolts are replaced by glue-ins now) If the shaft is steel there is a limit below which repeated loadings have not real effect, even if you're above this often the number of cycles is in the milions In a corrosive environment (warm seacliffs) all sorts of weird things can happen. So all up, it's not a problem on most US crags for good well placed stainless steel bolts of suitable diameter (which admittedly are a bit of a rarity, but it's getting better).
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