Climbing Rope Wear and Degradation

Report (winter 97/98) from the president of the UIAA safety commission, Pitt Schubert. His considerable experience of investigating dynamic climbing ropes produced some of the following findings....

1. Ropes cannot break in the tie in knot, or at the running belay.

2. Any rope can break when loaded over a sharp edge. It is not possible to produce a rope that is strong enough not to break when loaded over a sharp edge, however, the maximum chance for survival is with a new rope.

3. Use of twin rope has cut down on breakages.

4. There have been no known rope failures in sport climbing

5. Car battery acid damages ropes and cannot visibly be detected. In Germany there have been at three known cases where this has happened.

6.Petrol and Diesel do not damage ropes, even when left overnight to soak! WD40 caused no damage either.

7. Coke (the drinking variety) was not found to compromise the strength of a rope.

8. Autan (insect repellent), although damaging to plastic, was not found to damage ropes...in fact strength was slightly increased.

9. Sea water did not affect the strength of ropes.

10. Ropes soaked overnight in urine had their strength reduced by 30%, however, only when loaded over a sharp edge would this matter.

11. UV radiation does NOT damage ropes. Nylon is UV stabilised and only the colour will be lost.

12. Standing on a rope loaded over a right-angled metal edge with three times body weight did not reduce a ropes strength.

13. Standing on a rope in the snow with crampons did no damage. Neither did standing on it on rock with a 75kg body weight.In a further test Crampon points were forced right through the rope with no strength reduction/damage occurring!

14. The strength of frozen and wet ropes was reduced,but again, unless the rope is loaded over a sharp edge it would not matter.

15. The suggested lifespan of 10 years which has been given for ropes is to help the user determine lifespan . However, after contact with ICI it was found that although after 10 years there was a measurable degradation in nylon (not just in ropes, but all nylon textiles) ageing itself would not cause a rope to break, unless it was loaded over a sharp edge.

16. Top roping damaged ropes, but the damage was visible and could be felt, as was damage from stonefall.

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