The autoblock knot is an easy-to-tie friction knot that is used as a safety back-up knot on a rappel rope. The knot is tied onto the rope below the rappel device and then attached to the rappeller’s harness with a carabiner clipped into a leg loop or the belay loop. The knot, an essential safety knot that every climber should know, adds friction to the rappel descent, allowing the climber to safely stop mid-rappel to rearrange the rope or to keep from rappelling too fast and losing control.
