Consequences of poor rope drag management in a common fall - Petzl Other
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Consequences of poor rope drag management in a common fall

The first series of tests represent configurations with very little friction (protection points aligned). This configuration is common in the gym, but it is rare to find aligned points on single or multi-pitch climbs, where poor rope management can create significant drag. It thus seems important to study the influence of drag on a common fall. We did a series of falls with different rope paths.

Warnings

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Only the drag was changed, the other parameters were constant.

The belayer was gradually raised to keep the same rope length regardless of the rope path.

It is important to note that the drag is greatly exaggerated, in order to highlight its influence. In practice, it is rare to face such significant drag.

Test configuration with different drags
Test configuration with different drags


Test configuration with different drags

Force on the anchor

Force on the climber

Force on the belayer

Notes

• Significant drag prevents the full length of the rope from absorbing the energy of the fall. Only the last section of rope stretches, the actual fall factor increases.

• The effective rope length being shorter, the climber has the sensation of getting a hard catch when the fall is arrested.

• The belayer is pulled less (or not at all) during the fall: his displacement does not contribute to dissipating a part of the energy in play.

• The effect is to slightly increase the forces on the climber and the redirect point.



Advice

Anticipating the rope path and extending offset anchor points helps avoid situations with high rope drag.