Page 200 - Geoffrey Budworth, Jason Dalton "The Little Book of Incredibly Useful Knots"

Double Heddon knot

The extra turn of this reinforced Heddon knot (see pages 158–159) generates additional friction

and load-bearing, while making it harder to loosen. It works best with webbing.

Arrange the bight of a webbing sling around the climbing rope (1), and trap it with two wrapping
turns (2, 3). Tuck the other end of the sling through the bight (4) and load downward (5).