The constrictor knot is one of the most effective binding knots. Although Ashley seemed to imply that he had invented the constrictor knot over 25 years before publishing The Ashley Book of Knots,
Although the description is not entirely without ambiguity, the constrictor knot is thought to have appeared under the name "gunner's knot" in the 1866 work The Book of Knots, written under the pseudonym Tom Bowling. The knot is described in relation to the clove hitch, which he illustrated and called the "builder's knot". He wrote, "The Gunner's knot (of which we do not give a diagram) only differs from the builder's knot, by the ends of the cords being simply knotted before being brought from under the loop which crosses them." But Bowling is simply an extraction and translation of the knotting work contained in the huge French ', first published in 1841, which says "" When J. T. Burgess copied from Bowling, he changed this text to merely state "when the ends are knotted, the builder's knot becomes the gunner's Knot." Although a clove hitch with knotted ends is a workable binding knot, Burgess was not actually describing the constrictor knot. In 1917, A. Hyatt Verrill illustrated Burgess's clove hitch variation in Knots, Splices and Rope Work.
The constrictor knot was clearly described but not pictured as the "" ("timber knot") in the 1916 (2nd) edition of the Swedish book ' ("On Knots") by Hjalmar Öhrvall. Finnish scout leader Martta Ropponen presented the knot in her 1931 scouting handbook ' ("Knot Book"), one of the first published works known to contain an illustration of the constrictor knot.
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- Make a turn around the object and bring the working end back over the standing part.
- Continue around behind the object.
- Pass the working end over the standing part and then under the riding turn and standing part, forming an overhand knot under a riding turn.
- Be sure the ends emerge between the two turns as shown. Pull firmly on the ends to tighten.
There are also at least three methods to tie the constrictor knot in the bight and slip it over the end of an object to be bound.
Twisting method
Using both hands when the end of the object to tie to is available:
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File:SikistirmaBagi 1.JPG| 1 : Both hands holding the rope, thumbs are used to form a Z with the rope
File:SikistirmaBagi 2.JPG| 2 : thumbs with the rope are rotated 90 degrees to cross each other forming loops
File:SikistirmaBagi 3.JPG| 3 : The resulting two loops are folded around the crossing point and held together.
File:SikistirmaBagi 4.JPG| 4 : the resulting two loops are slipped together over the end
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If one or both of the ends are folded in between the two loops and lead in the opposite direction, the knot becomes slipped.
Folding method
preparing it using only one hand's fingers:
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File:Onehandconstrictor1.jpg|1 : a bight hanged behind ring and long finger, bottom end further inn
File:Onehandconstrictor2.jpg|2 : ring finger end of the bight hooked by the thumb from outside and up
File:Onehandconstrictor3.jpg|3 : long finger end of the bight hooked by the thumb from outside and down
File:Onehandconstrictor4.jpg|4 : the thumb pulls it past under the first, and rotates it by reaching out and up
File:Onehandconstrictor5.jpg|5 : long finger and thumb ends join to gather both loops around the thumb
File:Onehandconstrictor6.jpg|6 : the knot is ready to be transferred and tightened where needed
</gallery>
Using one hand when the end of the object to tie to is available:
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File:WürgeknotWerf1.jpg| 1 : Bight turned into an underhand loop and slipped loosely over the end of the object|alt=1 : Bight turned into an underhand (overhand) loop and slipped loosely over the end of the object
File:WürgeknotWerf2.jpg| 2 : The loop is grabbed from under, at the other side of crossing point, twisted half a turn (counter-)clockwise to form a number 8,
File:WürgeknotFertig3.jpg| 3 : Then lead over the loop crossing point and slipped a second time over the end, and finally tightened.
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If the rope is to be stretched in tension, the grabbing at stage 2 may first tighten the top side rope, the bottom side rope may be pulled to tighten the knot itself, and the bottom rope side may be tightened by the knot at the next pole. If one or both of the ends are folded and led in the opposite direction before the last loop is folded over the objects end, the knot becomes slipped and therefore easier to untie: It also makes it possible to stretch either side rope tight by pulling at the slip loops.
Variations
Double constrictor knot
If a stronger and even more secure knot is required an extra riding turn can be added to the basic knot to form a double constrictor knot. It is particularly useful when tying the knot with very slippery twine, especially when waxed. The knot has also been recommended as a surgical knot for ligatures in human and veterinary surgery, where it has been shown to be far superior to any of the knots commonly used for ligation. Noted master-rigger Brion Toss says of the constrictor: "To know the knot is to constantly find uses for it..."
Security
The constrictor and double constrictor are both extremely secure when tied tightly around convex objects with cord scaled for the task at hand. If binding around a not fully convex, or square-edged object, arrange the knot so the overhand knot portion is stretched across a convex portion, or a corner, with the riding turn directly atop it.