|Double Fisherman's knot|
|Names||Double Fisherman's knot, Grapevine, Double englishman's knot|
|Related||Fisherman's knot, Triple fisherman's knot, Double overhand knot, Strangle knot|
|Typical use||Joining thin, stiff or slippery lines, backing up critical knots such as the Figure-of-eight loop or Figure-of-eight follow through|
|Caveat||Difficult to untie|
The double fisherman's knot or grapevine knot is a bend. This knot and the triple fisherman's knot are the variations used most often in climbing, arboriculture, and search and rescue. The knot is formed by tying a double overhand knot, in its strangle knot form, with each end around the opposite line's standing part.
A primary use of this knot is to form high strength (round) slings of cord for connecting pieces of a climber's protection system.
This knot, along with the basic fisherman's knot can be used to join the ends of a necklace cord. The two strangle knots are left separated, and in this way the length of the necklace can be adjusted without breaking or untying the strand.
A study of 8 different bends using climbing ropes concluded "the Double Fisherman's Knot seemed to be the best joining knot". The butterfly bend held under slightly more weight, but "almost impossible to untie after a significant load of about 1,000 lb [4.4 kN] was applied".
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 rather than the traditional double fisherman's knot in 6 mm 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.
A knot is an intentional complication in cordage which may be useful or decorative. Practical knots may be classified as hitches, bends, splices, or knots. A hitch fastens a rope to another object; a bend unites two rope ends; a splice is a multi-strand bend or loop. A knot in the strictest sense serves as a stopper or knob at the end of a rope to keep that end from slipping through a grommet or eye. Knots have excited interest since ancient times for their practical uses, as well as their topological intricacy, studied in the area of mathematics known as knot theory.
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. Other names for the fisherman's knot include: angler's knot, English knot, halibut knot, waterman's knot.
A figure-eight loop is a type of knot created by a loop on the bight. It is used in climbing and caving where rope strains are light to moderate and for decorative purposes. The knot is commonly followed by tying a strangle knot or an overhand knot around the standing end.
The Flemish loop or figure-eight loop is perhaps stronger than the loop knot. Neither of these knots is used at sea, as they are hard to untie. In hooking a tackle to any of the loops, if the loop is long enough it is better to arrange the rope as a cat's paw.
A Zeppelin bend is a symmetrical and inherently secure end-to-end joining knot. It is remarkable because it is stable and secure and totally resistant to jamming. It is resistant to the effects of slack shaking and cyclic loading. There is no load test that has managed to induce jamming. The structure fundamentally consists of two interlinked overhand knots (#515). The Zeppelin bend has point inversion symmetry.
The klemheist knot or French Machard knot is a type of friction hitch that grips the rope when weight is applied, and is free to move when the weight is released. It is used similarly to a Prusik knot or the Bachmann knot to ascend or descend a climbing rope. One advantage is that webbing can be used as an alternative to cord. The Klemheist is easier to slide up than a Prusik. The klemheist is also a way to attach a snubber to the anchor rope of small boats, with the advantage that it is easy to undo.
A wide range of equipment is used during rock or any other type of climbing that includes equipment commonly used to protect a climber against the consequences of a fall.
The sheet bend is a bend. It is practical for joining lines of different diameter or rigidity.
A stopper knot is a knot that creates a fixed thicker point on an otherwise-uniform thickness rope for the purpose of preventing unreeving: stopping the rope at that point from slipping out of a narrow passage. Stopper has three distinct meanings in the context of knotting and cordage. A decorative stopper knot may be referred to as a lanyard knot.
The single-strand stopper knot is...[one variety] of knob knots. Generally it is tied as a terminal knot in the end of a rope, where it forms a knob or bunch, the general purpose of which is to prevent unreeving. It is found in the ends of running rigging. It secures the end of a sewing thread; it provides a handhold or a foothold in bell ropes and footropes. It adds weight to the end of a heaving line, and it is often employed decoratively, but it should not be used to prevent unlaying and fraying except in small cord, twine, and the like, as a whipping is in every way preferable for large and valuable material.
Kernmantle rope is rope constructed with its interior core protected by a woven exterior sheath designed to optimize strength, durability, and flexibility. The core fibers provide the tensile strength of the rope, while the sheath protects the core from abrasion during use.
The offset overhand bend is a knot used to join two ropes together. The offset overhand bend is formed by holding two rope ends next to each other and tying an overhand knot in them as if they were a single line. Due to its common use in several fields, this bend has become known by many names, such as thumb knot, openhand knot, one-sided overhand knot or flat overhand bend (FOB), though the terms "one-sided" and "flat" are considered incorrect.
Ultra-high-molecular-weight polyethylene is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene, (HMPE), it has extremely long chains, with a molecular mass usually between 3.5 and 7.5 million amu. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made.
A Prusik is a friction hitch or knot used to attach a loop of cord around a rope, applied in climbing, canyoneering, mountaineering, caving, rope rescue, ziplining, and by arborists. The term Prusik is a name for both the loops of cord and the hitch, and the verb is "to prusik". More casually, the term is used for any friction hitch or device that can grab a rope. The word is often misspelled as Prussik, Prussick or Prussic, as it is a homophone with the term prussic acid.
A sling or runner is an item of climbing equipment consisting of a tied or sewn loop of webbing. These can be wrapped around sections of rock, hitched to other pieces of equipment, or tied directly to a tensioned line using a Prusik style knot. They may be used as anchors, to extend an anchor to reduce rope drag, in anchor equalization, or to climb a rope.
The eye splice is a method of creating a permanent loop in the end of a rope by means of rope splicing.
A bowstring joins the two ends of the bow stave and launches the arrow. Desirable properties include light weight, strength, resistance to abrasion, and resistance to water. Mass has most effect at the center of the string; one gram (0.035 oz) of extra mass in the middle of the string slows the arrow about as much as 3.5 grams (0.12 oz) at the ends.
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 (UHMWPE) and aramid cored ropes.
The uni knot is a multi purpose fishing knot that can be used for attaching the fishing line to the arbor of a reel, for joining lines, and for attaching lures, snaps, and swivels.
The Abalakov thread, or V-Thread, is an ice protection device named after its innovator, Soviet climber Vitaly Abalakov. The Abalakov thread is a common method of protecting oneself while ice climbing because it is easy to create, does not require the sacrifice of expensive gear, and can be very safe when used properly. An Abalakov thread is often used in multi-pitch ice climbing routes. Because of its safety and convenience, the Abalakov thread is considered one of the most significant innovations in ice climbing. It significantly expanded the scope of possible routes and abseiling safety.
The harness knot is a general purpose bend knot used to join two ropes together. The knot can be tied under tension and will not capsize.