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The bowline ( or ) is an ancient and simple knot used to form a fixed loop at the end of a rope. It has the virtues of being both easy to tie and untie; most notably, it is easy to untie after being subjected to a load. The bowline is sometimes referred to as ''king of the knots'' because of its importance. Along with the sheet bend and the clove hitch, the bowline is often considered one of the most essential knots. The common bowline shares some structural similarity with the sheet bend. Virtually all end-to-end joining knots (i.e., bends) have a corresponding loop knot. Although the bowline is generally considered a reliable knot, its main deficiencies are a tendency to work loose when not under load (or under cyclic loading), to slip when pulled sideways, and the bight portion of the knot to capsize in certain circumstances. To address these shortcomings, a number of more secure variations of the bowline have been developed for use in safety-critical applications, or by securing the knot with an overhand knot backup.


History

The bowline's name has an earlier meaning, dating to the
age of sail The Age of Sail is a period that lasted at the latest from the mid-16th (or mid- 15th) to the mid- 19th centuries, in which the dominance of sailing ships in global trade and warfare culminated, particularly marked by the introduction of naval ...
. On a square-rigged ship, a bowline (sometimes spelled as two words, ''bow line'') is a rope that holds the edge of a square
sail A sail is a tensile structure—which is made from fabric or other membrane materials—that uses wind power to propel sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles. Sails may ...
towards the bow of the ship and into the wind, preventing it from being taken aback. A ship is said to be on a "taut bowline" when these lines are made as taut as possible in order to sail
close-hauled A point of sail is a sailing craft's direction of travel under sail in relation to the true wind direction over the surface. The principal points of sail roughly correspond to 45° segments of a circle, starting with 0° directly into the wind. ...
to the wind. The bowline knot is thought to have been first mentioned in
John Smith's John Smith's Brewery in Tadcaster, North Yorkshire, England, produces beers including John Smith's, the highest selling bitter in the United Kingdom since the mid-1990s. The majority of John Smith's sales are of the nitrogenated Extra Smooth ...
1627 work ''A Sea Grammar'' under the name Boling knot. Smith considered the knot to be strong and secure, saying, "The ''Boling knot'' is also so firmly made and fastened by the bridles into the
cringle A cringle is an eye through which to pass a rope. In nautical settings, the word refers to a small hole anywhere along the edge or in the corner of a sail, rimmed with stranded cordage and worked into the boltrope. Typically it encloses a meta ...
s of the sails, they will break, or the sail split before it will slip." Another possible finding was discovered on the rigging of the Ancient Egyptian Pharaoh Khufu's
solar ship Solar Ship Inc. is a company based in Toronto, Ontario, Canada working to develop a hybrid aircraft to deliver critical cargo to cut-off places. The solarship gains lift from both buoyant gas and aerodynamics, and uses power from solar panels. ...
during an excavation in 1954.


Usage

The bowline is used to make a loop at one end of a line. It is tied with the rope's
working end 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 ' ...
also known as the "tail" or "end". The loop may pass around or through an object during the making of the knot. The knot tightens when loaded at (pulled by) the standing part of the line. The bowline is commonly used in sailing small craft, for example to fasten a halyard to the head of a sail or to tie a
jib sheet In sailing, a sheet is a line (rope, cable or chain) used to control the movable corner(s) ( clews) of a sail. Terminology In nautical usage the term "sheet" is applied to a line or chain attached to the lower corners of a sail for the purpos ...
to a clew of a jib. The bowline is well known as a rescue knot for such purposes as rescuing people who might have fallen down a hole, or off a cliff onto a ledge. This knot is particularly useful in such a situation because it is possible to tie with one hand. As such, a person needing rescue could hold onto the rope with one hand and use the other to tie the knot around their waist before being pulled to safety by rescuers. The Federal Aviation Administration recommends the bowline knot for tying down light aircraft. A rope with a bowline retains approximately 2/3 of its strength, with variances depending upon the nature of the rope, as in practice the exact strength depends on a variety of factors. In the United Kingdom, the knot is listed as part of the training objectives for the Qualified Firefighter Assessment.


Tying

A mnemonic used to teach the tying of the bowline is to imagine the working end of the rope as a rabbit. * 1,2 – a loop is made into the standing part which will act as the rabbit's hole * 3 – the "rabbit" comes up the hole, * 4 – goes round the tree (standing part) right to left * 5 – and back down the hole This can be taught to children with the rhyme: "Up through the rabbit hole, round the big tree; down through the rabbit hole and off goes he." A single handed method can also be used; se
this animation
There is a potential with beginners to wrongly tie the bowline. This faulty knot stems from an incorrect first step while tying the rabbit hole. If the loop is made backwards so that the working end of the rope is on the bottom, the resulting knot will be the Eskimo bowline, looking like a sideways bowline, which is also a stable knot.


Security

As noted above, the simplicity of the bowline makes it a good knot for a general purpose end-of-line loop. However, in situations that require additional security, several variants have been developed:


Round turn bowline

The round turn bowline is made by the addition of an extra
turn Turn may refer to: Arts and entertainment Dance and sports * Turn (dance and gymnastics), rotation of the body * Turn (swimming), reversing direction at the end of a pool * Turn (professional wrestling), a transition between face and heel * Turn, ...
in the formation of the "rabbit hole" before the working end is threaded through.


Water bowline

Similar to the double bowline, the water bowline is made by forming a clove hitch before the working end is threaded through. It is said to be stronger and also more resistant to jamming than the other variations, especially when wet.


Yosemite bowline

In this variation the knot's working end is taken round the loop in the direction of the original round turn, then threaded back up through the original round turn before the knot is drawn tight. The Yosemite bowline is often used in climbing.


Other variants

The cowboy bowline (also called Dutch bowline),
French bowline {{unreferenced, date=September 2013 Some consider that a French bowline is the same as a Portuguese bowline, i.e. a bowline with two loops that can be used as a bosun's chair. A different knot is however also known as a French bowline. This form ...
, and Portuguese bowline are variations of the bowline, each of which makes one loop. (Names of knots are mostly traditional and may not reflect their origins.) A running bowline can be used to make a noose which draws tighter as tension is placed on the standing part of the rope. The ''Birmingham bowline'' has two loops; the working part is passed twice around the standing part (the "rabbit" makes two trips out of the hole and around the tree). Other two-loop bowline knots include the Spanish bowline and the
bowline on the bight The bowline on a bight is a knot which makes a pair of fixed-size loops in the middle of a rope. Its advantage is that it is reasonably easy to untie after being exposed to load. This knot can replace the figure-eight loop knot when tying into a ...
; these can be tied in the middle of a rope without access to the ends. A triple bowline is used to make three loops. A Cossack knot is a bowline where the running end goes around the loop-start rather than the main part and has a more symmetric triangular shaped knot. A slipped version of the Cossack knot is called
Kalmyk loop The Kalmyk Loop (russian: калмыцкий узел) is a fixed loop still largely unused in the West, but common in Russia and often used instead of the bowline. The knot is named after the Kalmyks, a nomad ethnicity in Russia. It is very q ...
. Tying video for Kalmyk loop File:Birmingham_Bowline_Loose.jpg, Two-loop Birmingham bowline before tightening and dressing the knot. Two turns taken around the standing part of the line form two loops. File:Four knots.jpg, Variants: File:Bowline to 6 2 knot.gif, If a bowline is tied and the two free ends of the rope are brought together in the simplest way, the
mathematical knot In mathematics, a knot is an embedding of the circle into three-dimensional Euclidean space, (also known as ). Often two knots are considered equivalent if they are ambient isotopic, that is, if there exists a continuous deformation of ...
obtained is the so-called
6₂ knot In knot theory, the 62 knot is one of three prime knots with crossing number six, the others being the stevedore knot and the 63 knot. This knot is sometimes referred to as the Miller Institute knot, because it appears in the logo of the Mill ...
. The sequence of necessary moves is depicted here.


See also

* List of knots * Karash double loop * Eye splice * Bowline on a bight


Notes


References


External links


Video of the Lightning Method

YouTube animation of a Bowline knot
{{Knots