Trucker's hitch

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Trucker's hitch
TruckersHitchUsingAlpineButterfly2.jpg
Trucker's hitch with alpine butterfly loop
NamesTrucker's hitch, dolly knot, Wakos transport knot, [1] lorry driver's hitch, [2] harvester's hitch, [2] hay knot, [3] sheepshank cinch, [3] trucker's dolly, [4] wagoner's hitch, [4] power cinch, [5] rope tackle [6]
Category Hitch
Related versatackle knot, sheepshank
Typical useMaking a rope very tight, such as to secure an object to a vehicle
CaveatCan produce excessive wear on rope, especially if tied repeatedly in the same spot [6]
ABoK #1514, #2124, #2125, #2126
Instructions

The trucker's hitch is a compound knot commonly used for securing loads on trucks [7] 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. [2] [3] 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. [8]

Contents

Variations

The portion of the trucker's hitch which differs in the following variations is the method used to form the loop which the working end slides through to produce the mechanical advantage. The different methods of forming the loop affect the ease and speed of tying and releasing and the stability of the final product.

The variations are presented in order of increasing stability.

Sheepshank style loop

This version of the knot uses a sheepshank-like construction, in this kind of application also known as a bell ringer's knot, to form the loop. It is quicker to make than a fixed loop, but is less dependable. [2] [9] It is avoided in critical applications (such as securing a load on a truck) as it can fall apart under too little load or too much load, and can capsize if not dressed properly. [4] However, this knot may be made secure by adding a Half Hitch by using the top bight of the Sheepshank. This form of the trucker's hitch is least likely to jam, coming apart easily once tension is released. Different sources show slight variations in the way the sheepshank portion is formed and dressed.

Versions popular in East Asia use variations of sheep shank using either a simple half hitch [10] or a double turn self crossing half hitch [11] or a triple turn self crossing half hitch. [12] A sheep shank with two consecutive half hitches i.e. a clove hitch to secure the upper eye and to form the lower eye is more popular in the west.

Slipped overhand loop

The loop formed in one version is a simple Slipped Overhand Loop. This version is good for light to moderate loads

Simple friction loop

Another version uses a multiply twisted bight to pass a bight of the working end to form the eye of the loop. This version tolerates higher load. [13]

Fixed loop

The most reliable common variation uses a fixed loop, such as an alpine butterfly loop, artillery loop, figure-eight loop or directional figure-eight loop, or another of many suitable loop knots. [4] [14] If a fixed loop is used repeatedly for tying the trucker's hitch in the same portion of rope, excessive wear or other damage may be suffered by the portion of the loop which working end slides against. [2]

If extra loops are used to form the eye it tends to ease untying. In order to prevent the closing of the loop under load, the loop must be formed by the working end of the rope (which will later pass through the loop). If the standing end goes through the loop, it will close under load.

Finishing the hitch

In tightening the trucker's hitch, tension can be effectively increased by repeatedly pulling sideways while preventing the tail end from slipping through the loop, and then cinching the knot tighter as the sideways force is released. This is called "sweating a line". [15]

Once tight, the trucker's hitch is often secured with a half hitch, usually slipped for easy releasing and to avoid the necessity of access to the end of the rope, though a more secure finish, such as two half-hitches, may be called for. Under large loads, the finishing half hitch can jam, especially if it is not slipped; the difficulty of releasing it can be compounded by the fact that the knot is typically still under tension when it is untied.

Finishing with a taut-line hitch or a Farrimond friction hitch to the standing part allows the finishing knot to be tied and untied with no tension. This eliminates any jamming problems and also allows the line to be re-tensioned if necessary.

Mechanical advantage and friction

Conceptually similar arrangement of pulleys PolispastoN.jpg
Conceptually similar arrangement of pulleys

All common variations of the trucker's hitch use a loop in the standing part of the rope and the anchor point as makeshift pulleys in order to theoretically obtain a 3 to 1 mechanical advantage while pulling on the working end.

There is sometimes confusion about how much theoretical mechanical advantage is provided by the trucker's hitch. If the trucker's hitch were to be used as in the pulley diagram at right, to lift a weight off the floor, the theoretical mechanical advantage would be only 2:1. However in the common use of the trucker's hitch, a static hook, ring, or rail, serves as the lower pulley, and the rope across the top of the load is the portion being tensioned. Thus, the standing part of the rope is represented by the top anchor point in the diagram, and the theoretical ratio is indeed 3:1 when the working end is tensioned. That is, in a frictionless system, every unit of force exerted on the working end would produce 3 units in the standing part of the rope over the load. In the typical use of the trucker's hitch, where it is used to tighten a rope over a load, when the end is secured to the loop of the Truckers hitch and let go, the tension in the two segments of rope around the ring will rise 50%, unless the rope slackens when it is being tied off, in which case the tension may drop to any value or even zero if enough slack is allowed. But when the trucker's hitch is used as in the diagram, after tying off, the load on the attachment point above the top pulley will drop to 100 N and the tension in the two lines going to the lower pulley will not change.

Theoretical considerations aside, in real world use the mechanical advantage of the trucker's hitch is significantly less than the ideal case due to the effects of friction. Friction has been reported to reduce the mechanical advantage from 3 to 1, to well less than 2 to 1 in many cases. One advantage of the friction within the trucker's hitch, compared to a hypothetical pulley-based system, is that it allows the hitch to be held taut with less force while the working end is secured.

Cultural references

The trucker's hitch knot is portrayed by comedy duo Ylvis in their 2014 song with the same name. The lyrics and the video pretend (in a humorous way) to demonstrate how to tie the knot. [16]

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.

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.

Sheepshank

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.

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.

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.

Block and tackle system of two or more pulleys and a rope or cable

A block and tackle or only tackle is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift heavy loads.

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.

Cats paw (knot)

The Cat's paw is a knot used for connecting a rope to an object. It is very similar to the cow hitch except there is an additional twist on each side of the bight, making it less prone to slipping.

The cat's-paw is the common hook hitch for slings. It is the same basic form as the bale sling hitch but has additional twists. Brady says "two or three altogether," and Steel, who mentioned the name in 1794, says "three twists." It is the best of all sling hitches and is often recommended for a slippery rope. But no hitch can slip when tied in a slings since it has no ends. All that is needed is a hitch that cannot jam, and this requirement the cat's-paw fills admirably. The knot spills instantly when removed from the hook. It is the hitch always used for heavy lifts.

Sheet bend

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

Munter hitch Adjustable knot used control friction in a belay system

The Munter hitch, also known as the Italian hitch, Mezzo Barcaiolo or the Crossing Hitch, is a simple adjustable knot, commonly used by climbers, cavers, and rescuers to control friction in a life-lining or belay system. To climbers, this hitch is also known as HMS, the abbreviation for the German term Halbmastwurfsicherung, meaning half clove hitch belay. This technique can be used with a special "pear-shaped" HMS locking carabiner, or any locking carabiner wide enough to take two turns of the rope.

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.

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.

Halter hitch

The halter hitch is a type of knot used to connect a rope to an object. As the name implies, an animal's lead rope, attached to its halter, may be tied to a post or hitching rail with this knot. The benefit of the halter hitch is that it can be easily released by pulling on one end of the rope, even if it is under tension. Some sources show the knot being finished with the free end running through the slipped loop to prevent it from working loose or being untied by a clever animal, still allowing easy but not instant untying.

Z-drag

A Z-Drag or Z-Rig is an arrangement of lines and pulleys, effectively forming a block and tackle, that is commonly used in rescue situations. The basic arrangement results in pulling the hauling end 3 times the distance the load is moved, providing a theoretical mechanical advantage of three to one. In actual practice the advantage will be reduced by friction in the pulleys or carabiners. The advantage will also be reduced if the pull on the hauling end is not parallel to the direction the load moves in. The name comes from the fact that the arrangement of lines is roughly Z shaped. Besides the mechanical advantage to pulling, it also uses only part of the total length of the rope for the block and tackle arrangement.

Farrimond friction hitch

The Farrimond friction hitch is a quick release adjustable friction hitch 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 or adjust tension whilst remaining quick and easy to untie; such as when hanging the ridge line for a Basha. It can be used in very effective conjunction with the Siberian hitch for this purpose. It can also be used as a mooring knot.

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. Lofty Wiseman, The Sas Survival Handbook
  2. 1 2 3 4 5 Des Pawson (2002), Pocket Guide to Knots & Splices, Edison, NJ: Chartwell Books, Inc., p. 142
  3. 1 2 3 Cyrus Lawrence Day (1986), The Art of Knotting and Splicing (4th ed.), Annapolis: Naval Institute Press, p. 116
  4. 1 2 3 4 Gordon Perry (2006), Knots, North Vancouver: Quantum Publishing, pp. 134–135
  5. Cliff Jacobson (1977), Wilderness Canoeing & Camping, Dutton, p. 118, ...there seems to be no widely accepted name for this hitch, so I took the liberty of naming it the power-cinch
  6. 1 2 Riley, Howard W. (January 1912). "Knots, Hitches, and Splices". The Cornell Reading-Courses. Rural Engineering Series No. 1. Ithaca, NY: New York State College of Agriculture at Cornell University. 1 (8): 1428. Retrieved 2011-11-08. As collected in Documents of the Assembly of the State of New York, 136th Session, 1913, Vol. 19, No. 29, Part 5.
  7. Heavy Vehicle Road Code, New Zealand, 2016
  8. Geoffrey Budworth (1999), The Ultimate Encyclopedia of Knots, London: Hermes House, pp. 224–225
  9. Ashley, Clifford W. (1944), The Ashley Book of Knots, New York: Doubleday, p. 344, A quicker but less dependable lashing is based on the Bell Ringer's Knot #1148.
  10. https://www.youtube.com/watch?v=jTiGUYhW1A8 Truckers' hitch using a simple turn half hitch sheep shank eye
  11. https://www.youtube.com/watch?v=_Y4xcd-e6rA Truckers' hitch using a double and crossing turn sheep shank eye
  12. https://www.youtube.com/watch?v=H9_yT8HJF64 Trucker's hitch using a double and crossing turn sheep shank upper eye, and twisted lower eye
  13. https://www.youtube.com/watch?v=tvgFyqFZK54 The Truckers' Hitch - tied 3 different ways
  14. Ashley, p. 271
  15. John Mellor (1996), Handling Troubles Afloat, Dobbs Ferry, NY: Sheridan House, pp. 195–196
  16. Video on YouTube