| Bowline | |
|---|---|
 | |
| Names | Bowline, Boling knot (archaic) |
| Category | Loop |
| Origin | Ancient |
| Related | Sheet bend,Double bowline,Water bowline,Yosemite bowline,Spanish bowline,Portuguese bowline,Triple bowline,Bowline on a bight,Running bowline,Poldo tackle,Eskimo bowline,Cowboy bowline,Cossack knot,Kalmyk loop |
| Releasing | Non-jamming[1] |
| Typical use | Making a fixed loop at the end of a line. |
| Caveat | While widely considered a reliable knot, when tied in certain materials or loading conditions it may not hold. Tends to work itself loose when not under tension. |
| ABoK | #1010, #1716 |
| Instructions | [1] |
Thebowline (/ˈboʊlɪn/) is an ancient and simpleknot 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 asking of the knots because of its importance. Along with thesheet bend and theclove hitch, the bowline is often considered one of the most essential knots.[2]
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),[3][4] to slip when pulled sideways,[5] and thebight portion of the knot tocapsize in certain circumstances.[6] To address these shortcomings, a number of more secure variations of the bowline have been developed for use insafety-critical applications, or by securing the knot with anoverhand knot backup.
The bowline's name has an earlier meaning, dating to theage of sail. On asquare-rigged ship, a bowline (sometimes spelled as two words,bow line) is a rope that holds the edge of a squaresail towards thebow of the ship and into the wind, preventing it from beingtaken aback.[7] A ship is said to be on a "taut bowline" when these lines are made as taut as possible in order to sailclose-hauled to the wind.[8]
The bowline knot is thought to have been first mentioned inJohn Smith's 1627 workA Sea Grammar under the nameBoling knot. Smith considered the knot to be strong and secure, saying, "TheBoling knot is also so firmly made and fastened by the bridles into thecringles of the sails, they will break, or the sail split before it will slip."[9][a]
Another possible finding was discovered on the rigging of theAncient EgyptianPharaohKhufu'ssolar ship during an excavation in 1954.[10]
The bowline is used to make a loop at one end of a line. It is tied with the rope'sworking end 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 ahalyard to the head of a sail or to tie ajib sheet to aclew of ajib. 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. TheFederal Aviation Administration recommends the bowline knot for tying down lightaircraft.[11]
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.[12]
Amnemonic used to teach the tying of the bowline is to imagine the working end of the rope as a rabbit.
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."
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 theEskimo bowline, looking like a sideways bowline, which is also a stable knot.
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:
The round turn bowline is made by the addition of an extraturn in the formation of the "rabbit hole" before the working end is threaded through.
Similar to the double bowline, the water bowline is made by forming aclove 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.
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 inclimbing.
Thecowboy bowline (also called Dutch bowline),French bowline, andPortuguese bowline are variations of the bowline, each of which makes one loop. (Names of knots are mostly traditional and may not reflect their origins.) Arunning bowline can be used to make a noose which draws tighter as tension is placed on the standing part of the rope. TheBirmingham 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 theSpanish bowline and thebowline on the bight; these can be tied in the middle of a rope without access to the ends. Atriple bowline is used to make three loops.[13] ACossack 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 calledKalmyk loop.[14][15]
stopper knot is mandatory … tends to spontaneously loosen under cyclic loading … is not recommended to use this knot in life-critical applications
This form of the Simple Bowline is resistant to ring loading but is still not suitable for mission critical applications.
...as well as a curiously intricate knot on a piece of rigging that appeared to be basically akin to a bowline knot.
