The jury mast knot (or masthead knot) is traditionally used for

jury rig In maritime transport terms, and most commonly in sailing, jury-rigged is an adjective, a noun, and a verb. It can describe the actions of temporary makeshift running repairs made with only the tools and materials on board; and the subsequent r ...

ging a temporary mast on a

sailboat A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing boat and ship vary by region and maritime culture. Types Although sailboat terminolo ...

ship A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...

after the original one has been lost. The

knot A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ' ...

is placed at the top of a new mast with the mast projecting through the center of the knot. The loops of the knot are then used as anchor points for makeshift stays and

shrouds Shroud usually refers to an item, such as a cloth, that covers or protects some other object. The term is most often used in reference to '' burial sheets'', mound shroud, grave clothes, winding-cloths or winding-sheets, such as the famous S ...

. Usually small blocks of wood are affixed to, or a groove cut in, the new mast to prevent the knot from sliding downwards.Clifford W. Ashley, ''

The Ashley Book of Knots ''The Ashley Book of Knots'' is an encyclopedia of knots written and illustrated by the American sailor and artist Clifford W. Ashley. First published in 1944, it was the culmination of over 11 years of work. The book contains 3,857 numbered en ...

'' (New York: Doubleday, 1944), 212. Due to a lack of hard historical evidence there is uncertainty whether this supposed rigging knot was ever commonly used for rigging jury masts.Charles Hamel, "Investigations on the Jury Mast Knot

(URLs retrieved 2007-02-22)

Variations

There are three closely related variations of this knot. They differ based on the type of crossing, overhand or underhand, of the three initial loops and then whether the edges of each loop is positioned over or under the previous one. Although these knots are tied in the Bight (knot), bight, for the purposes of description the left side will be considered the standing part. If all the crossings and overlays are reversed, or the right side is taken as the standing part, a mirror image of the knot will result.

#1167

This variation grips the mast best in the absence of other means to prevent the knot from sliding downwards. The pattern of this variation, from the left, is: under-under-under/over-over.

#1168

This variation is the simplest of the three in structure (though not in tying) and lends itself to being reinforced by tying a

reef knot The reef knot, or square knot, is an ancient and simple binding knot used to secure a rope or line around an object. It is sometimes also referred to as a Hercules knot. The knot is formed by tying a left-handed overhand knot between two ends, ...

with the two free ends. The pattern of this variation, from the left, is: under-over-under/over-over.

#1169

According to

Clifford Ashley Clifford Warren Ashley (December 18, 1881 – September 18, 1947) was an American artist, author, sailor, and knot expert. Life Ashley was born in New Bedford, Massachusetts, son of Abiel Davis Ashley and Caroline Morse. He married Sarah Scudder ...

this is the preferred variation. The pattern of this variation, from the left, is: under-under-under/under-under.

References

External links

Description of tying a Masthead knot
{{Knots Sailing rigs and rigging