Tarbuck knot

From Freepedia

Canonical name: Tarbuck knot.
Variant name(s): Unknown.
Category: Slip knot.
Origin: Modern.
Related knot(s): Hangman's knot, noose.
Releasing: Non-jamming.
Efficiency: 32%
Caveat: The knot grips adequately, but under sudden stress will slide to a limited extent thus reducing shock.
Uses: Climbing
Comments: The tarbuck knot was developed by Kenneth Tarbuck for use by climbers, and is primarily used with nylon ropes. It is often used when the rope is subject to heavy or sudden strains. The knot is non-jamming.