A Fireman's chair knot (or simply chair knot) is a knot tied in the bight forming two adjustable, lockable loops. The knot consists of a Handcuff knot finished with a locking half hitch around each loop. The loops remain adjustable until the half hitches are tightened.
Made in suitable rope by trained personnel this knot can be used as a rescue harness capable of supporting a person while they are lowered to safety. One loop supports the body, around the chest and under the arms, and the other supports the legs, under the knees. Tied towards the middle of a line, one end is used for lowering and the other manned below to control the victim's position with respect to hazards during the descent. A snug fitting of this knot should not allow the person to fall, even if unconscious.