Editing Self-locking device (section)

===Gibbs-style type 1 ascender===

[[Image:Gibbs_Ascender.jpg|thumb|150px|right|A Gibbs-style ascender]]The next level of device development improved on the locking limitations of the prusik sling by utilizing a [[Spring loaded camming device|cam]] that is activated by the climber's body moving down to rotate the simple grab cam inside a rigid frame. The climber's harness is directly attached to the cam and the frame encapsulates the rope.

Early versions of the cam systems used a Gibbs-style type 1 ascender placed in an inverted position attached to a soloer's [[Climbing harness|sit harness]] opposite to the manufacturer's intended use. The combination of a climber's body position in a fall and friction between the ascender frame and the rope provides the activating leverage for the cam to grab the rope. Fall forces generated using this device and the cam profile can be enough to damage a rope due to the high clamp loads induced by the cam lever arm. The main drawback to this system is that it is like the prussik knot system where the soloer also has to feed out an estimated amount of rope in order to reach a stance point.