Chockstone Forum

      Sponsored By
      ROCK
   HARDWARE

Chockstone Photography

Australian Landscape Prints

Chockstone Forum - General Discussion

General Climbing Discussion

Topic Date User

Double, twin or single rope ...? 21-May-2004 At 10:11:07 AM M

Message

an easy experiment to demonstrate this effect is to get two elastic bands. place one over a finger and your thumb and open you hand quickly so that the elastic band resists. now use two elastic bands. its more difficult and you can feel more force on your finger and thumb. the elastic band is a bit like a dynamic rope and the thumb and finger are the climber and top anchor. Two elastic bands like two ropes will exert more force than one.
If you want to be technical this experiment is far from perfect as with you hand you will just increase the force to compensate, opening the rubber bands just as far. A falling climber doesnt get any heavier or fall faster on two ropes so the result is that the ropes wont stretch as far. because the ropes dont stretch as far the climber will stop quicker. the climber stops more quickly (negative acceleration) because there is more force exerted on them over a shorter period of time. more force on the climber means more force on the top anchor.

my understanding of the rope burn issue is that this only occurs if the ropes have been seperated and returned together. I also feel that serious rope burn would be pretty rare even if the ropes were seperated and returned together but I dont know for sure.