Sheepshank
Encyclopedia
The sheepshank is a type of knot
that is used to shorten a rope
or take up slack. This knot is not stable. It will fall apart under too much load or too little load.
The knot has several features which allow a rope to be shortened:
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.
, and in sailing
applications.
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.
. Constructed from such ropes, under load, it can fail. It is strongly advised that an alternative knot be used.
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
.
The "Kamikaze Knot" is a slight variant of the Sheepshank. To perform a kamikaze knot, you must first construct a sheepshank. Whilst holding quite sufficient tension on the sheepshank so it will not slip out, slice the middle rope with your free hand. What you have just done will save you a lot of rope if you are repelling down a cliff. Just remember... never use thin or slippery rope for the kamikaze knot, because if it slips, you will fall. When you get to the bottom you can easily shake the rope a few times, and the knot at the top will disconnect, giving you nearly all your rope back. Remember, safety first. Never perform unless desperately needed.
Quint asks Hooper to "tie me a sheepshank" as proof of his seamanship.
In the motion picture Follow Me, Boys!
. Lem Siddons, after mistakenly being taken POW during US Army War Games, is asked by a Lieutenant to "tie a sheepshank" to prove he's a Scoutmaster and not a spy.
Bear Grylls
uses the Kamikaze Knot to scale down a cliff during his Ireland episode.
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"...
that is used to shorten a rope
Rope
A rope is a length of fibres, twisted or braided together to improve strength for pulling and connecting. It has tensile strength but is too flexible to provide compressive strength...
or take up slack. This knot is not stable. It will fall apart under too much load or too little load.
The knot has several features which allow a rope to be shortened:
- It provides two loops, one at each end of the knot which can be used to pass another rope through
- The knot remains somewhat secure under tension; the coarser the rope the more secure it is (see Disadvantages, below)
- The knot falls apart easily when tension is removed
Construction methods
A sheepshank knot may be constructed as follows: ...- Pull a section of rope back and lay it alongside the rope, so that the rope forms a Z approximately 20 cm long.
- Flatten the Z so that there are 3 sections of rope lying alongside each other, with two U-bends where the rope reverses direction.
- At each U-bend, grasp the U-bend in one hand, thus holding two of the rope sections. With the other hand form a small loop in the remaining section and draw it over the U-bend so that the loop forms a half hitch and stays there if the free end of the rope is pulled taut.
-
- 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.
- Repeat at the other U-bend.
- 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:
- Create a simple loop in the rope, so that the (left) leading end is on top of the (right) trailing end of the loop.
- Repeat this process further down the rope to create 3 total loops that overlap slightly (similar to a venn diagramVenn diagramVenn diagrams or set diagrams are diagrams that show all possible logical relations between a finite collection of sets . Venn diagrams were conceived around 1880 by John Venn...
with three circles). - Reach through the outer two loops and grab either side of the middle loop and pull outward while also keeping the rest of the rope slightly taut.
- Once the middle loop is pulled through the outer loops, pull on the free ends of the rope to secure.
The result is a flattened loop which is held at each end by a half hitch
Half hitch
The half hitch is a simple overhand knot, where the working end of a line is brought over and under the standing part. Insecure on its own, it is a valuable component of a wide variety of useful and reliable hitches, bends, and knots....
. 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.
Usage
Sheepshank knots are typically used for securing loads to trucks or trailersTrailer (vehicle)
A trailer is generally an unpowered vehicle pulled by a powered vehicle. Commonly, the term trailer refers to such vehicles used for transport of goods and materials....
, and in sailing
Sailing
Sailing is the propulsion of a vehicle and the control of its movement with large foils called sails. By changing the rigging, rudder, and sometimes the keel or centre board, a sailor manages the force of the wind on the sails in order to move the boat relative to its surrounding medium and...
applications.
Bear Grylls
Bear Grylls
Edward Michael "Bear" Grylls is an English adventurer, writer and television presenter. He is best known for his television series Man vs. Wild, known as Born Survivor in the United Kingdom...
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
Man vs. Wild
Man vs. Wild, also called Born Survivor: Bear Grylls, Ultimate Survival, or Survival Game, is a survival television series hosted by Bear Grylls on the Discovery Channel. In the United Kingdom, the series was originally shown on Channel 4, but later series were broadcast on Discovery Channel UK...
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.
Disadvantages
The sheepshank was developed before the use of modern "slippery" synthetic ropesSynthetic fiber
Synthetic fibers are the result of extensive research by scientists to improve on naturally occurring animal and plant fibers. In general, synthetic fibers are created by forcing, usually through extrusion, fiber forming materials through holes into the air, forming a thread...
. Constructed from such ropes, under load, it can fail. It is strongly advised that an alternative knot be used.
Man-o'war sheepshank
The man-o'war sheepshank is a sheepshank knotKnot
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"...
with a Handcuff knot
Handcuff knot
A handcuff knot is a knot tied in the bight having two adjustable loops in opposing directions, able to be tightened around hands or feet. The knot itself does not possess any inherent locking action, and thus is not as easy to use for such purposes as the name might suggest.The knot is also known...
in the middle. This configuration with the half-hitches formed close to the central knot is used in rope rescue
Rope rescue
Rope rescue is a subset of technical rescue that involves the use of static nylon kernmantle ropes, anchoring and belaying devices, friction rappel devices, various devices to utilize mechanical advantage for hauling systems, and other specialized equipment to reach victims and safely recover...
and is called a Fireman's chair knot
Fireman's chair knot
A fireman's chair knot is a knot tied in the bight forming two adjustable, lockable loops. The knot consists of a handcuff knot finished with a locking half hitch around each loop...
.
Kamikaze knot
The "Kamikaze Knot" is a slight variant of the Sheepshank. To perform a kamikaze knot, you must first construct a sheepshank. Whilst holding quite sufficient tension on the sheepshank so it will not slip out, slice the middle rope with your free hand. What you have just done will save you a lot of rope if you are repelling down a cliff. Just remember... never use thin or slippery rope for the kamikaze knot, because if it slips, you will fall. When you get to the bottom you can easily shake the rope a few times, and the knot at the top will disconnect, giving you nearly all your rope back. Remember, safety first. Never perform unless desperately needed.
Popular culture
In the motion picture JawsJaws (film)
Jaws is a 1975 American horror-thriller film directed by Steven Spielberg and based on Peter Benchley's novel of the same name. In the story, the police chief of Amity Island, a fictional summer resort town, tries to protect beachgoers from a giant man-eating great white shark by closing the beach,...
Quint asks Hooper to "tie me a sheepshank" as proof of his seamanship.
In the motion picture Follow Me, Boys!
Follow Me, Boys!
Follow Me, Boys! is a 1966 family film released through Walt Disney Pictures, based on the book God and My Country by MacKinlay Kantor. It was the last production released before Walt Disney died of lung cancer...
. Lem Siddons, after mistakenly being taken POW during US Army War Games, is asked by a Lieutenant to "tie a sheepshank" to prove he's a Scoutmaster and not a spy.
Bear Grylls
Bear Grylls
Edward Michael "Bear" Grylls is an English adventurer, writer and television presenter. He is best known for his television series Man vs. Wild, known as Born Survivor in the United Kingdom...
uses the Kamikaze Knot to scale down a cliff during his Ireland episode.
External links
- Sheepshank & Variants
- Boatsafe.com
- Animation of tying a sheepshank knot
- Project Gutenberg (September 21, 2004). The Project Gutenberg eBook, Knots, Splices and Rope Work, by A. Hyatt Verrill. Retrieved November 6, 2005. Though the name's a little different, the Sheepshank described above is shown in Figure 79.
- Scouting Resources. Sheepshank. Retrieved December 11, 2006. Shows diagrams with accompanying text.