Bight (knot)

The term bight is used in knot tying to refer to any curved section, slack part, or loop between the two ends of a rope, string, or yarn.Clifford W. Ashley, "The Ashley Book of Knots" (New York: Doubleday, 1944), 597.] An important concept, the term is used extensively in the description of knots and the discourse of knotting and related subjects.

A familiar practical use is finishing a knot by passing a bight, rather than the end, to make a slipped form of the knot which is more easily untied. The traditional bow knot used for tying shoelaces is simply a reef knot with the final overhand knot made with two bights instead of the ends.

The term is also used in a more specific way when describing Turk's head knots, indicating how many repetitions of braiding are made in the circuit of a given knot.Ashley, 232.]

In the bight

The phrase in the bight (or on a bight) means a bight of line is itself being used to make a knot. Specifically this means that the knot can be formed without access to the ends of the rope.Ashley, 207.] This can be an important property for knots used in situations where the ends of the rope are inaccessible, such as forming a fixed loop in the middle of a long climbing rope.

Many knots normally tied with an end also have a form which is tied in the bight, for instance the bowline and the bowline on a bight. In other cases a knot being tied in the bight is a matter of the method of tying rather than a difference in the completed form of the knot. For example the clove hitch can be made in the bight if it is being slipped over the end of a post but not if being cast onto a closed ring, which requires access to an end of the rope. Other knots, such as the overhand knot, cannot be tied in the bight without changing their final form.

Examples

References