The sheepshank is a type of knot that is used to shorten a rope or take up slack. This knot is not stable. It can easily just fall apart under too much load or too little load.
The knot has several features which allow a rope to be shortened:
- It provides two loops, one at each end of the knot which can be used to pass another rope through
- The knot remains somewhat secure under tension; the coarser the rope the more secure it is (see Disadvantages, below)
- The knot falls apart easily when tension is removed
Sheepshank knots are typically used for securing loads to trucks or trailers, and in sailing applications.
Bear Grylls uses a modification of this knot by cutting one of the lengths of rope in the knot, while rappelling down an edge during the Ireland episode of Man vs. Wild in order to retrieve his rope at the bottom by severing the middle leg of the sheepshank knot before his descent. He refers to it as a "kazikame" knot.