Editing Taut-line hitch

{{Short description|Adjustable hitch knot}}
{{Infobox knot
| name=Taut-line hitch
| image= Topsegelschotstek.jpg
| names= Adjustable hitch, Rigger's hitch, Tent-line hitch, Tent hitch
| type= Hitch
| origin= 
| related= [[Magnus hitch]], [[Rolling hitch]], [[Two half-hitches]], [[Trucker's hitch]], [[Adjustable grip hitch]]
| releasing= 
| strength= 
| uses=
| caveat=
| abok_number= #62, #1027, #1230, #1729, #1730, '''#1799''', '''#1800''', '''#1855''', '''#1856''', '''#1857''', #1993
| instructions=
}}

The '''taut-line hitch''' is an adjustable [[Loop (knot)|loop knot]] for use on lines under [[Tension (mechanics)|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.

It is typically used for securing [[tent]] lines in outdoor activities involving [[camping]], by [[arborists]] when climbing trees,<ref name="sonhitch">{{Citation|first=Mark|last=Adams|title=Son of a Hitch: A Genealogy of Arborists' Climbing Hitches|url=http://www.treebuzz.com/pdf/0505_geneology.pdf|publisher=[[International Society of Arboriculture]]|journal=Arborist News|date=April 2005}}</ref> for tying down aircraft,<ref name="tiedown">{{Citation|first=Jeff|last=Pardo|title=Tying the Knot: Know the ropes so your aircraft won't be gone with the wind|url=http://flighttraining.aopa.org/magazine/2004/October/200410_Features_Tying_the_knot.html|publisher=[[AOPA|Airplane Owners and Pilots Association]]|journal=Flight Training|date=October 2004}}</ref> for creating adjustable [[Mooring (watercraft)|moorings]] in [[Tide|tidal]] areas,<ref name="tossrigg">{{Citation|first=Brion|last=Toss|title=The Complete Rigger's Apprentice|location=Camden|publisher=International Marine|year=1998|pages=54–55}}</ref> 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]].<ref name="hubble">{{Cite journal|first=Tom|last=Nugent|title=Blanketing the Hubble|journal=University of Delaware Messenger|volume=6|number=3 |year=1997|url=http://www.udel.edu/PR/Messenger/97/3/BLANKET.html}}</ref>

== Naming ==
[[Image:AdjustableHitchVariations.jpg|thumb|'''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''',<ref name="tossrigg"/> '''tent-line hitch''',<ref name="tossrigg"/> '''rigger's hitch''',<ref name="tossrigg"/> '''adjustable hitch''',<ref name="ashley304">{{citation |last=Ashley |first=Clifford W. |title=The Ashley Book of Knots |year= 1944 |publisher=Doubleday |location=New York |page=304}}</ref> or '''midshipman's hitch'''.<ref name="ashley304"/>  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 [[Rolling hitch#Naming|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 knot#Nautical usage|stopper]].<ref name="riley1912">{{cite journal|last=Riley|first=Howard W.|author-link=Howard W. Riley|journal=The Cornell Reading-Courses|title=Knots, Hitches, and Splices|series=Rural Engineering Series No. 1|volume=1|issue=8|publisher=New York State College of Agriculture at Cornell University|location=Ithaca, NY|date=January 1912|page=1425|url=https://books.google.com/books?id=bNNKAAAAMAAJ&pg=PA1425|access-date=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.</ref>

== 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.

[[Image:TautlineHitch-ABOK-1799.jpg|left|550px]] {{clear|left}}

# 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.
# 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.
# Complete with a half-hitch outside the loop, made in the same direction as the first two wraps, as for a [[clove hitch]].
# 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]].<ref name="bshb12">{{Citation|author=Boy Scouts of America|title=The Boy Scout Handbook|edition=12th|location=Irving|publisher=BSA|year=2009|page=385}}</ref>  The earliest [[Boy Scout Handbook]] to include the taut-line hitch was the 5th edition, published in 1948.<ref name="bshbhist5">{{Citation|title=The Boy Scout Handbook 1910-Today|first=Jeff|last=Snowden|edition=4th|year=2009|url=http://www.troop97.net/bshb_ed5.htm|publisher=Troop 97 BSA}}</ref>  However it illustrated #1855, the variant shown above.<ref name="bshb5">{{Citation|author=Boy Scouts of America|title=Handbook for Boys|edition=5th|publisher=BSA|year=1949|pages=94–95}}</ref>

[[Image:TautlineHitch-ABOK-1800.jpg|left|550px]] {{clear|left}}

# 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.
# Continue with another wrap inside the loop, effectively making a [[round turn]] around the standing part.
# Complete with a half-hitch outside the loop, made in the same direction as the first two wraps, as for a clove hitch.
# 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.
[[Image:TautlineHitch-ABOK-1800-reversed.jpg|left|550px]] {{clear|left}}

# 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.
# Continue with another wrap inside the loop, effectively making a round turn around the standing part.
# Complete with a half-hitch outside the loop made in the opposite direction than the first two wraps, as for a [[cow hitch]].
# 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&nbsp;cm from the aircraft and adjusted for tension, then a second taut-line hitch is tied 5–20&nbsp;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 ==
[[File:Dining fly (tent).svg|thumb|Adjusting the [[guy-line]]s 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<ref name="ashley298">Ashley(1944), p. 298</ref> and others<ref name="tossrigg"/><ref name="trower">{{Citation|first=Nola|last=Trower|title=Helmsman Guides: Knots and Ropework|location=Wiltshire|publisher=Helmsman Books|year=1995|pages=31–32}}</ref> suggest that #1855 is preferred as being more [[Knot#Security|secure]].  Either #1856 or #1857 is also acceptable, especially if ease of adjustment is desired over security.<ref name="ashley296">Ashley(1944), p. 296</ref><ref name="tossguide">{{Citation|first=Brion|last=Toss|title=Chapman's Nautical Guides: Knots|location=New York|publisher=Hearst Marine Books|year=1990|pages=30–32}}</ref>  Ashley states #1857 has less tendency to twist.<ref name="ashley304"/>

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-hitch]]es.<ref name="tossguide"/>

== Friction hitches==
<ref>{{Cite web|url=http://www.paci.com.au/downloads_public/knots/14_Report_hitches_PBavaresco.pdf|title=Ropes and Friction Hitches used in Tree Climbing Operations|last=Bavaresco|first=Paolo|date=2002|website=Professional Association of Climbing Instructors PACI.com}}</ref> 
These as a family are called Friction Hitches<ref name="sonhitch" /> or hold and release to slide hitches<ref>{{Cite web|url=http://treebuzz.com/pdf/climbing_hitches.pdf|title=Climber's Corner an Overview of Climbing Hitches|last=Adams|first=Mark|date=October 2004|website=treebuzz.com}}</ref>

The similar ABoK numbers are in ABoK's unique "Chapter 22: Hitches to Masts, Rigging and Cable (Lengthwise Pull)<ref name="ashley304" /> 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."<ref name="ashley304" /> A Friction Hitch is on a rope column that you are grabbing with "Lengthwise pull" force wise in this chapter.<ref name="ashley304" />  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".<ref name="ashley304" />  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 first knot in the chapter right after the previous discussion as context .<ref name="ashley304" />  After showing the Half-Hitch preceding as only conversion for the direction adds: "The knot appears to be universal and invariable"!  <ref name="ashley304" />

== See also ==
* [[List of knots]]
* [[Magnus hitch]]
* [[Blake's hitch]]

== References ==
{{reflist}}

{{Knots}}