Tarbuck knot

The Tarbuck knot was made popular around 1952 by Kenneth Tarbuck, a climber and skier, for use by climbers, and was primarily used with stranded nylon ropes, before the advent of kernmantle ropes made this use both unnecessary and unsafe.^[1][2] It was used when the rope is subject to heavy or sudden loads,^[3] as it will slide to a limited extent thus reducing shock (but with kernmantle ropes it can strip the outer sheath).^[2] The knot was already employed by 1946 as "the knot" by American tree trimmers.^[4]

Tarbuck knot
Category	Running
Efficiency	32%
Origin	Kenneth Tarbuck
Releasing	Non-jamming
Typical use	Climbing (obsolete)
Caveat	The knot grips adequately, but under sudden stress will slide to a limited extent thus reducing shock loading.