Sheepshank

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Sheepshank
Sheepshank knot.jpg
An unloaded sheepshank tied in nylon rope.
Category Shortening
Origin 1627 [1]
Related Catshank, Dogshank, Bell-ringer's knot
Releasing Non-jamming
Typical useProvides loops, shortens or removes slack from a rope, bypasses a frayed section of rope
CaveatSpills if not under tension.
ABoK #1152, #1153, #1154, #1158, #1159, #1160
Instructions

A shank is a type of knot that is used to shorten a rope or take up slack, such as the sheepshank. The sheepshank knot is not stable. It will fall apart under too much load or too little load.

Contents

The knot has several features which allow a rope to be shortened:

Construction methods

A sheepshank knot may be constructed as follows: ...

Many people draw the small loop over facing the wrong way at least half of the time. Instead, make with the U a half-hitch around the other part, by tucking through, then pull the U straight.

An alternative method for quickly constructing a sheepshank is as follows:

The result is a flattened loop which is held at each end by a half hitch. If the sides of the flattened loop are pulled away from each other, the flattened loop ends pull out of the half hitches and the knot falls apart, but if the free ends are pulled taut then the knot remains secure.

Modern Usage

Sheepshank knots are typically used for securing loads to trucks or trailers, and in sailing applications.

Disadvantages

The sheepshank was developed before the use of modern "slippery" synthetic ropes. Constructed from such ropes, under load, it can fail. It is strongly advised that an alternative knot be used.

Variants

Man-o'war sheepshank

The man-o'war sheepshank is a sheepshank knot with a Handcuff knot in the middle. This configuration with the half-hitches formed close to the central knot is used in rope rescue and is called a Fireman's chair knot.

Man-o'-war-sheepshank.png

Sheepshank with Marlinespike hitches

This version of the sheepshank is tied by using slipknots instead of half-hitches. It is one of the safest sheepshank variations. [2]

Kamikaze knot

Kamikaze.JPG

The kamikaze knot is a slight variant of the sheepshank. To perform a kamikaze knot, a sheepshank is first constructed. Whilst holding sufficient tension on the sheepshank so it will not slip out, the middle rope is sliced. This allows climbers rappelling down cliff faces to keep most of the rope used for the rappel, by tying the knot at the top, and shaking the rope when they reach the bottom. The shaking disconnects the knot at the top, allowing the longer section of rope to fall, meaning only a small amount of rope is retained by the anchor at the top of the cliff. Thin or slippery rope is unsuitable for such a knot, as it can easily slip, and the knot should not be performed unless desperately needed.

Use

Although certainly not invented by him this variant of the sheepshank knot appeared in an episode of the TV show Man Vs Wild. Bear Grylls uses a modification of this knot by cutting one of the lengths of rope in the knot, while rappelling down an edge during the Ireland episode of Man vs. Wild in order to retrieve his rope at the bottom by severing the middle leg of the sheepshank knot before his descent. He refers to it as a "Kamikaze" knot.

Bell-ringer's knot

A simpler variant of the sheepshank wherein a half-hitch is only tied around only one end produces a bell-ringer's knot (ABoK #1147). It will immediately spill under tension, and is used to keep a long rope from the belfry deck when not in use.

Catshank

Catshank
Catshank.jpg
Category Shortening
RelatedSheepshank, Dogshank

The catshank is a variant of the sheepshank, clinched by two overhand knots with the bights passed through the twists (one end of the rope must be available to tie the overhands). [3]

Dogshank

Dogshank
Dogshank.gif
Category Shortening
RelatedSheepshank, Catshank, Bowline
Typical useShortening rope

The dogshank, or sheepshank pouch knot, is a variant of the sheepshank where the eyes formed at each end have the ends of the rope passed through them to prevents the knot from spilling. At least one end of the rope must be available to tie or untie this knot. It is mostly useful for the hammock-like space it creates. [4]

The dogshank can be thought of as two opposite bowlines where

Further reading

See also

Related Research Articles

Knot Method of fastening or securing linear material

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 bend fastens two ends of a rope to each another; a loop knot is any knot creating a loop, and splice denotes any multi-strand knot, including bends and loops. A knot may also refer, in the strictest sense, to 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.

Bowline Simple knot used to form a fixed loop at the end of a rope

The bowline 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.

Butterfly loop Knot used to form a fixed loop in the middle of a rope

The butterfly loop, also known as lineman's loop, butterfly knot, alpine butterfly knot and lineman's rider, is a knot used to form a fixed loop in the middle of a rope. Tied in the bight, it can be made in a rope without access to either of the ends; this is a distinct advantage when working with long climbing ropes. The butterfly loop is an excellent mid-line rigging knot; it handles multi-directional loading well and has a symmetrical shape that makes it easy to inspect. In a climbing context it is also useful for traverse lines, some anchors, shortening rope slings, and for isolating damaged sections of rope.

Constrictor knot binding knot

The constrictor knot is one of the most effective binding knots. Simple and secure, it is a harsh knot that can be difficult or impossible to untie once tightened. It is made similarly to a clove hitch but with one end passed under the other, forming an overhand knot under a riding turn. The double constrictor knot is an even more robust variation that features two riding turns.

Clove hitch

The clove hitch is a type of knot. Along with the bowline and the sheet bend, it is often considered one of the most important knots. A clove hitch is two successive half-hitches around an object. It is most effectively used as a crossing knot. It can be used as a binding knot, but is not particularly secure in that role. A clove hitch made around the rope's own standing part is known as either two half-hitches or buntline hitch, depending on whether the turns of the clove hitch progress away from or towards the hitched object.

Although the name clove hitch is given by Falconer in his Dictionary of 1769, the knot is much older, having been tied in ratlines at least as early as the first quarter of the sixteenth century. This is shown in early sculpture and paintings. A round turn is taken with the ratline and then a hitch is added below. The forward end is always the first to be made fast.

The difference between two half hitches and the clove hitch is that the former, after a single turn around a spar, is made fast around its own standing part, while the latter is tied directly around the spar.

Truckers hitch

The trucker's hitch is a compound knot commonly used for securing loads on trucks or trailers. This general arrangement, using loops and turns in the rope itself to form a crude block and tackle, has long been used to tension lines and is known by multiple names. Knot author Geoffrey Budworth claims the knot can be traced back to the days when carters and hawkers used horse-drawn conveyances to move their wares from place to place.

Taut-line hitch

The taut-line hitch is an adjustable loop knot for use on lines under tension. It is useful when the length of a line will need to be periodically adjusted in order to maintain tension. It is made by tying a rolling hitch around the standing part after passing around an anchor object. Tension is maintained by sliding the hitch to adjust the size of the loop, thus changing the effective length of the standing part without retying the knot.

Timber hitch

The timber hitch is a knot used to attach a single length of rope to a cylindrical object. Secure while tension is maintained, it is easily untied even after heavy loading.

Zeppelin bend

A Zeppelin bend is an end-to-end joining knot formed by two symmetrically interlinked overhand knots. It is stable, secure, and highly resistant to jamming. It is also resistant to the effects of slack shaking and cyclic loading.

Overhand knot with draw-loop

A slipped half hitch is a knot in which the weight of the load the rope carries depresses the loop sufficiently to keep it in place until the load item is placed in its location. When no longer required the free end may be pulled and draw the loop through and so release the load.

Sheet bend

The sheet bend is a bend. It is practical for joining lines of different diameter or rigidity.

Cow hitch

The cow hitch, also called the lark's head, is a hitch knot used to attach a rope to an object. The cow hitch comprises a pair of half-hitches tied in opposing directions, as compared to the clove hitch in which the half-hitches are tied in the same direction. It has several variations and is known under a variety of names. It can be tied either with the end of the rope or with a bight.

Buntline hitch

The buntline hitch is a knot used for attaching a rope to an object. It is formed by passing the working end around an object, then making a clove hitch around the rope's standing part and taking care that the turns of the clove hitch progress towards the object rather than away from it. Secure and easily tied, the buntline hitch will jam when subjected to extreme loads. Given the knot's propensity to jam, it is often made in slipped form.

The buntline hitch, when bent to a yard, makes a more secure knot than two half hitches, but is more liable to jam. It differs from two half hitches in that the second half hitch is inside instead of outside the first one.

Offset overhand bend Knot used to join two ropes together

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.

Rolling hitch

The rolling hitch is a knot used to attach a rope to a rod, pole, or another rope. A simple friction hitch, it is used for lengthwise pull along an object rather than at right angles. The rolling hitch is designed to resist lengthwise movement for only a single direction of pull.

Prusik knot

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 used to tie the hitch and the hitch itself, and the verb is "to prusik". More casually, the term is used for any friction hitch or device that can grab a rope. Due to the pronunciation, the word is often misspelled Prussik, Prussick, or Prussic.

Highpoint hitch

The highpoint hitch is a type of knot used to attach a rope to an object. The main feature of the hitch is that it is very secure, yet if tied as a slipped knot it can be released quickly and easily with one pull, even after heavy loading. The highpoint hitch is tied in the same manner as a slipped buntline hitch until the final turn, where they diverge.

Harness bend

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.

Tumble hitch

The tumble hitch is a "slip-free", quick-release hitch knot used for temporarily securing a rope such that it can be released easily to be completely free of the hitched-to object. The hitch might be able to be untied with a tug of the working end, even when under tension; but the workings depend upon materials and forces; note that in some cases, "under tension" will amount to simply being tied and the line itself giving significant tension by weight. The tumble hitch is tied in the bight.

References

  1. knot, hitch, and splice :: Sheepshank. - Britannica Student Encyclopaedia
  2. Ashley, Clifford W. (1944), The Ashley Book of Knots, New York: Doubleday, p. 210
  3. Graumont, Raoul (1945) Handbook of Knots.[ full citation needed ]
  4. http://notableknotindex.webs.com/sheepshank.html Sheepshank & Variants