Page 297 - Geoffrey Budworth, Jason Dalton "The Little Book of Incredibly Useful Knots"

Scaffold hitch

A pair of these knots can be used, if no purpose-made equipment is available, to suspend an

improvised seat for the sort of work undertaken by steeplejacks and tree surgeons. At first
glance it seems identical to the pole hitch (see pages 236–237), but it has an extra crossing point
and an almost sleight-of-hand method of tying.

With the rope’s end, make two turns around one end of a plank or scaffold (1, 2). Lift up the rope

part furthest from the working end and replace it in the middle of the three strands (3). Then pick
up the displaced middle strand and leapfrog it over the remaining two knot parts (4) to pass
underneath the plank (5), or whatever is being tied. Finally, pick up both standing part and
working end of the rope and knot them together (6)—with, for instance, a stopped bowline.