Double fisherman's knot
Encyclopedia
The double fisherman's knot or grapevine knot is a bend, or a knot
Knot
A knot is a method of fastening or securing linear material such as rope by tying or interweaving. It may consist of a length of one or several segments of rope, string, webbing, twine, strap, or even chain interwoven such that the line can bind to itself or to some other object—the "load"...

 used to join two lengths of rope. This knot and the triple fisherman's knot
Triple fisherman's knot
The triple fisherman's knot is a bend knot, used to join two ends of rope together. It is an extension of the double fisherman's knot and is recommended for tying slippery, stiff ultra high molecular weight polyethylene and aramid cored ropes....

 are the variations used most often in climbing
Climbing
Climbing is the activity of using one's hands and feet to ascend a steep object. It is done both for recreation and professionally, as part of activities such as maintenance of a structure, or military operations.Climbing activities include:* Bouldering: Ascending boulders or small...

, arboriculture
Arboriculture
Arboriculture is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants. It is both a practice and a science....

, and search and rescue
Search and rescue
Search and rescue is the search for and provision of aid to people who are in distress or imminent danger.The general field of search and rescue includes many specialty sub-fields, mostly based upon terrain considerations...

. The knot is formed by tying a double overhand knot, in its strangle knot
Strangle knot
The strangle knot is a simple binding knot. Similar to the constrictor knot, it also features an overhand knot under a riding turn. The difference is that the ends emerge at the outside edges, rather than between the turns as for a constrictor. This knot is actually a rearranged double overhand...

 form, with each end around the opposite line's standing part.

Usage

A primary use of this knot is to form high strength loops of cord for connecting pieces of a climber's protection system
Climbing equipment
A wide range of equipment is used during rock climbing. The most popular types of climbing equipment are briefly described in this article. The article on protecting a climb describes equipment commonly used to protect a climber against the consequences of a fall....

. Another common use for this knot is to back up a critical knot, such as a harness tie-in knot or single-line rappel rigs. In this use, the running end is tied around the standing end of the rope, so that it cannot slip back through the knot.

Other uses

This knot, along with the basic fisherman's knot
Fisherman's knot
The fisherman's knot is a bend with a symmetrical structure consisting of two overhand knots, each tied around the standing part of the other...

 can be used to join the ends of a necklace cord. The two double overhand knots are left separated, and in this way the length of the necklace can be adjusted without breaking or untying the strand.

Security

Dyneema/Spectra's very high lubricity leads to poor knot-holding ability, and has led to the recommendation to use the triple fisherman's knot
Triple fisherman's knot
The triple fisherman's knot is a bend knot, used to join two ends of rope together. It is an extension of the double fisherman's knot and is recommended for tying slippery, stiff ultra high molecular weight polyethylene and aramid cored ropes....

rather than the traditional double fisherman's knot in 6mm Dyneema core cord to avoid a particular failure mechanism of the double fisherman's, where first the sheath fails at the knot, then the core slips through.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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