Taut-line hitch

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Taut-line hitch
Topsegelschotstek.jpg
NamesTaut-line hitch, Adjustable hitch, Rigger's hitch, Midshipman's hitch, Tent-line hitch, Tent hitch
Category Hitch
Related Rolling hitch, Two half-hitches, Trucker's hitch, Adjustable grip hitch
ABoK #62, #1027, #1230, #1729, #1730, #1799, #1800, #1855, #1856, #1857, #1993
Instructions

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.

Contents

It is typically used for securing tent lines in outdoor activities involving camping, by arborists when climbing trees, [1] for tying down aircraft, [2] for creating adjustable moorings in tidal areas, [3] and to secure loads on vehicles. A versatile knot, the taut-line hitch was even used by astronauts during STS-82, the second Space Shuttle mission to repair the Hubble Space Telescope. [4]

Naming

Top, left to right: ABOK "Rolling hitch(1)"(#1734), "rolling hitch(2)"(#1735), "Magnus Hitch"(#1736). Bottom, the corresponding adjustable loop made using the hitch above it, left to right: "adjustable hitch"(#1800, #1856), "midshipman's hitch"(#1855), "adjustable hitch" with the concluding hitch reversed.(#1857) AdjustableHitchVariations.jpg
Top, left to right: ABOK "Rolling hitch(1)"(#1734), "rolling hitch(2)"(#1735), "Magnus Hitch"(#1736). Bottom, the corresponding adjustable loop made using the hitch above it, left to right: "adjustable hitch"(#1800, #1856), "midshipman's hitch"(#1855), "adjustable hitch" with the concluding hitch reversed.(#1857)

The adjustable loop forms of the rolling hitch and Magnus hitch, in addition to being called either of those two names, have also come to be known variously as the taut-line hitch, [3] tent-line hitch, [3] rigger's hitch, [3] adjustable hitch, [5] or midshipman's hitch. [5] These knots are generally shown as being based on one of three underlying hitches: two variants of the rolling hitch (ABOK #1734 and #1735) and the Magnus hitch (#1736).

These three closely related hitches have a long and muddled naming history that leads to ambiguity in the naming of their adjustable loop forms as well. The use of the Ashley reference numbers for these inconsistently named hitches can eliminate ambiguity when required. See the adjacent image for an illustration of these related knots.

An early use of the taut-line hitch name is found in Howard W. Riley's 1912 Knots, Hitches, and Splices, although it is shown in the rolling hitch form and suggested for use as a stopper. [6]

Tying

#1855

Ashley uses the name midshipman's hitch for this variation. Based on rolling hitch #1735, this version is considered the most secure but may be more difficult to adjust after being heavily loaded.

TautlineHitch-ABOK-1799.jpg
  1. Pass the working end around the anchor object. Bring it back alongside of the standing part and make a half-hitch around the standing part.
  2. Continue by passing the working end over the working part, around the standing part again and back through the loop formed in the first step. Make sure this second wrap tucks in between the first wrap and the working part of the line on the inside of the loop. This detail gives this version its additional security.
  3. Complete with a half-hitch outside the loop, made in the same direction as the first two wraps, as for a clove hitch.
  4. Dress by snugging the hitch firmly around the standing part. Load slowly and adjust as necessary.

#1856

Based on rolling hitch #1734, this version is the one most often seen named taut-line hitch, typically in non-nautical sources. It is the method currently taught by the Boy Scouts of America. [7] The earliest Boy Scout Handbook to include the taut-line hitch was the 5th edition, published in 1948. [8] However it illustrated #1855, the variant shown above. [9]

TautlineHitch-ABOK-1800.jpg
  1. Pass the working end around the anchor object. Bring it back alongside of the standing part and make a half-hitch around the standing part.
  2. Continue with another wrap inside the loop, effectively making a round turn around the standing part.
  3. Complete with a half-hitch outside the loop, made in the same direction as the first two wraps, as for a clove hitch.
  4. Dress by snugging the hitch firmly around the standing part. Load slowly and adjust as necessary.

#1857

Based on Magnus hitch #1736, this is exactly as above but with the final hitch in the opposite direction. It can be more tricky to snug-up, since both lines emerge from the same side of the hitch, but it has less tendency to twist under load.

TautlineHitch-ABOK-1800-reversed.jpg
  1. Pass the working end around the anchor object. Bring it back alongside of the standing part and make a half-hitch around the standing part.
  2. Continue with another wrap inside the loop, effectively making a round turn around the standing part.
  3. Complete with a half-hitch outside the loop made in the opposite direction than the first two wraps, as for a cow hitch.
  4. Dress by snugging the hitch firmly around the standing part. Load slowly and adjust as necessary.

This is the form most commonly used for aircraft tie-down. One taut-line hitch is tied 15–30 cm from the aircraft and adjusted for tension, then a second taut-line hitch is tied 5–20 cm further from the aircraft and finished with a half-hitch. Wind-induced lift tends to pull the knot tighter, gust-induced oscillations tend to damp-out, and once the half hitch is undone, pushing the lower working rope up easily releases both hitches even amid icing.

Adjusting

Adjusting the guy-lines of a tent is a common use for the taut-line hitch. Dining fly (tent).svg
Adjusting the guy-lines of a tent is a common use for the taut-line hitch.

Once snug and set, the hitch can be adjusted as needed. To tighten the line with respect to a load attached to the standing part, the user can grasp the standing part with one hand inside of the loop and pull toward the anchor object. The hitch may be grasped with the other hand and as slack develops within the loop, the hitch slid away from the anchor object, taking up the slack and enlarging the loop. To loosen, the hitch may be slid toward the anchor object, making the loop smaller and lengthening the standing part.

Security

Although the three variations are similar, they do have distinct properties when put to use. Ashley [10] and others [3] [11] suggest that #1855 is preferred as being more secure. Either #1856 or #1857 is also acceptable, especially if ease of adjustment is desired over security. [12] [13] Ashley states #1857 has less tendency to twist. [5]

These hitches may not hold fast under all conditions, and with lines made from particularly stiff or slick modern fibers (e.g. polypropylene) these hitches can be difficult to make hold at all. Sometimes they can be made more secure by using additional initial wraps and finishing half-hitches. [13]

Friction hitches [14]

These as a family are called Friction Hitches [1] of hold and release to slide hitches [15]

The similar ABoK numbers are in ABoK's unique "CHAPTER 22: HITCHES TO MASTS, RIGGING AND CABLE (LENGTHWISE PULL)" [5] 1st paragraph reads: "To withstand a lengthwise pull without slipping is about the most that can be asked of a hitch. Great care must be exercised in tying the following series of knots, and the impossible must not be expected." [5] A Friction Hitch is on a rope column that you are grabbing with "LENGTHWISE PULL" force wise in this chapter [5] . Not at the best (right) angle to host mount the rest of the book speaks of and shows for working hitches and thus chapter title and preface states. And so, the Friction Hitches are contained in this chapter on the errant pull angle stated as "LENGTHWISE PULL" [5] . Book shows a 'linear' Half Hitch to precede a Timber Hitch (that shows should pull at right angle to spar) so can pull LENGTHWISE in ABoK#"1733. The TIMBER HITCH AND HALF HITCH" Killick hitch perhaps best demonstrates the directional force effect as he shows it as the very first knot in the chapter right after the previous discussion as context . [5] After showing the Half-Hitch preceding as only conversion for the direction adds: "The knot appears to be universal and invariable"! [5]

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.

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.

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.

Packers knot

The packer's knot is a binding knot which is easily pulled taut and quickly locked in position. It is most often made in small line or string, such as that used for hand baling, parcel tying, and binding roasts. This latter use, and its general form, make it a member of a class of similar knots known as butcher's knots. The knot is commonly taught to Guides and Scouts, and those in similar organizations as a basic binding 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.

Klemheist knot

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.

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.

Munter hitch Adjustable knot used control friction in a belay system

The Munter hitch, also known as the Italian hitch 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 knot 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. The Munter hitch is named after Werner Munter, a Swiss mountain guide who popularised its use in mountaineering.

Blakes hitch

The Blake's hitch is a friction hitch commonly used by arborists and tree climbers as an ascending knot. Unlike other common climbing hitches, which often use a loop of cord, the Blake's hitch is formed using the end of a rope. Although it is a stable knot, it is often backed up with a stopper knot, such as a figure-of-eight knot, for safety. It is used for both ascending and descending, and is preferred by many arborists over other hitches, such as the taut-line hitch, as it is less prone to binding.

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

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. 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.

The magnus hitch is a knot similar to a rolling hitch or clove hitch, used to tie a rope or line to a pole, spar, or another line. It is tied similarly to a rolling hitch but with the final hitch in the opposite direction. It can be more tricky to snug up, since both lines emerge from the same side of the hitch, but it has less tendency to twist under load.

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 a buntline hitch with an extra half turn, making it more secure.

Gripping sailors hitch

The gripping sailor's hitch is a secure, jam-proof friction hitch used to tie one rope to another, or a rope to a pole, boom, spar, etc., when the pull is lengthwise along the object. It will even grip a tapered object, such as a marlin spike, in the direction of taper, similar to the Icicle hitch, but superior. It is much superior to the rolling hitch for that purpose. It is similar to the Michoacan-Martin friction knot used in climbing; The finishing wrap for Michoacan-Martin is in the opposite direction of the Gripping Sailors knot, both ends are then made to carry weight.

Jamming knot

As a type of binding knot, the jamming knot is good for constricting a bundle of objects such as sticks or brush. It is basically a taut-line hitch but the initial two wraps are on the outside of the working line rather than on the inside, and finished off with one wrap on the inside. Thus the knot holds tension towards the inside of the loop rather than the standing end of the rope as with the taut-line – turning a tension knot into a constricting knot. After the knot is tied, the knot is held with one hand, the standing end is pulled tight, and the knot should hold fast. This knot, as with the taut-line, can be difficult or impossible to tie on slick or particularly stiff rope.

References

  1. 1 2 Adams, Mark (April 2005), "Son of a Hitch: A Genealogy of Arborists' Climbing Hitches" (PDF), Arborist News, International Society of Arboriculture
  2. Pardo, Jeff (October 2004), "Tying the Knot: Know the ropes so your aircraft won't be gone with the wind", Flight Training, Airplane Owners and Pilots Association
  3. 1 2 3 4 5 Toss, Brion (1998), The Complete Rigger's Apprentice, Camden: International Marine, pp. 54–55
  4. Nugent, Tom (1997). "Blanketing the Hubble". University of Delaware Messenger. 6 (3).
  5. 1 2 3 4 5 6 7 8 9 Ashley, Clifford W. (1944), The Ashley Book of Knots, New York: Doubleday, p. 304
  6. 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): 1425. Retrieved 2011-11-26. As not collected in Documents of the Assembly of the State of New York, 136th Session, 1913, Vol. 19, No. 29, Part 5.
  7. Boy Scouts of America (2009), The Boy Scout Handbook (12th ed.), Irving: BSA, p. 385
  8. Snowden, Jeff (2009), The Boy Scout Handbook 1910-Today (4th ed.), Troop 97 BSA
  9. Boy Scouts of America (1949), Handbook for Boys (5th ed.), BSA, pp. 94–95
  10. Ashley(1944), p. 298
  11. Trower, Nola (1995), Helmsman Guides: Knots and Ropework, Wiltshire: Helmsman Books, pp. 31–32
  12. Ashley(1944), p. 296
  13. 1 2 Toss, Brion (1990), Chapman's Nautical Guides: Knots, New York: Hearst Marine Books, pp. 30–32
  14. Bavaresco, Paolo (2002). "Ropes and Friction Hitches used in Tree Climbing Operations" (PDF). Professional Association of Climbing Instructors PACI.com.
  15. Adams, Mark (October 2004). "Climber's Corner an Overview of Climbing Hitches" (PDF). treebuzz.com.