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impulse force on cams 14-Sep-2005 At 1:32:26 PM changie

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My physics is also pretty rusty. If between 20 years since uni and 10 since I've had to do this sort of calc so here goes...

Assuming the belayer is as close as practical to vertically below the cam. If the climber weighs 80kg then the section of rope between the climber and the karabiner carries 80kg. The rope then curls around the karabiner back down to the belayer. Assuming no losses, doesn't the rope between the karabiner and the belayer also need to support 80kg (or the rope starts to accelerate)? So, if I am not mistaken (big if) you have the same rope with forces in it pointing in the same direction (downwards) leading to a static load in the karabiner (and hence the support - whatever it is) of 0.16kN (160kg).

The same logic, if correct, would apply to dynamic/impact loads. Haven't investigated the referenced equations but one shouldn't be so brazen as to assume they are correct...

Changie