Sheepshank

Sheepshank
An unloaded sheepshank tied in nylon rope.
Category Shortening
Origin 1627[1]
Related Catshank, Dogshank
Releasing Non-jamming
Typical use Provides loops, shortens or removes slack from a rope, bypasses a frayed section of rope
Caveat Spills if not under tension.
ABoK #1152 - #1154
Instructions

The sheepshank is a type of knot that is used to shorten a rope or take up slack. This knot is not stable. It will fall apart under too much load or too little load.

The knot has several features which allow a rope to be shortened:

Construction methods

A sheepshank knot may be constructed as follows: ...

Many people draw the small loop over facing the wrong way at least half of the time. Instead, make with the U a half-hitch around the other part, by tucking through, then pull the U straight.

An alternative method for quickly constructing a sheepshank is as follows:

The result is a flattened loop which is held at each end by a half hitch. If the sides of the flattened loop are pulled away from each other, the flattened loop ends pull out of the half hitches and the knot falls apart, but if the free ends are pulled taut then the knot remains secure.

Usage

Sheepshank knots are typically used for securing loads to trucks or trailers, and in sailing applications.

Disadvantages

The sheepshank was developed before the use of modern "slippery" synthetic ropes. Constructed from such ropes, under load, it can fail. It is strongly advised that an alternative knot be used.

Variants

Man-o'war sheepshank

The man-o'war sheepshank is a sheepshank knot with a Handcuff knot in the middle. This configuration with the half-hitches formed close to the central knot is used in rope rescue and is called a Fireman's chair knot.

Sheepshank with Marlingspike hitches

This version of the sheepshank is tied by using slipknots instead of half-hitches. It is one of the safest sheepshank variations. [2]

Kamikaze knot

The kamikaze knot is a slight variant of the sheepshank. To perform a kamikaze knot, a sheepshank is first constructed. Whilst holding sufficient tension on the sheepshank so it will not slip out, the middle rope is sliced. This allows climbers rappelling down cliff faces to keep most of the rope used for the rappel, by tying the knot at the top, and shaking the rope when they reach the bottom. The shaking disconnects the knot at the top, allowing the longer section of rope to fall, meaning only a small amount of rope is retained by the anchor at the top of the cliff. Thin or slippery rope is unsuitable for such a knot, as it can easily slip, and the knot should not be performed unless desperately needed.

Use

Although certainly not invented by him this variant of the sheepshank knot appeared in an episode of the TV show Man Vs Wild. 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 "Kamikaze" knot.

See also

References

  1. knot, hitch, and splice :: Sheepshank. - Britannica Student Encyclopaedia
  2. Ashley, Clifford W. (1944), The Ashley Book of Knots, New York: Doubleday, p. 210

External links