Self-locking device

Self-locking devices are pieces of rock-climbing equipment intended to arrest the fall of solo climbers who climb without partners.

Early versions of the cam systems used a Gibbs-style type 1 ascender placed in an inverted position attached to a soloer's sit harness opposite to the manufacturer's intended use.

Knowledge of the correct device position relative to the rope anchor is critical for the correct operation of the cam devices in a fall as they are mono-directional in operation, and the soloer must be aware that he needs to put in a runner as soon as he sets off above the belay point on a multi-pitch climb, otherwise he can slide to the bottom of the rope in the event of a fall.

The Silent Partner is unique in the sense that it operates in both directions of drum rotation so it can be attached to a climber's sit harness in either position, eliminating the danger of stepping off a multi-pitch anchor point before the first runner can be placed.

The rope diameter and elasticity is critical for operation, as higher than normal fall forces can be generated due to the rapid locking rate, in the order of 13 kN at runners and anchor points.