View source for Bowline on a bight

{{short description|Knot that makes a pair of fixed-size loops in the middle of a rope}}
{{Knot-details
| name=Bowline on a Bight
| image= Doppelter Palstek.jpg
| names=
| type= loop
| strength=
| origin=
| related= [[Double bowline]]
| releasing= Non-jamming
| uses= Forming a loop in the middle of a length of rope.
| caveat=
| abok_number= #1080
}}

The '''bowline on a bight''' is a [[knot]] which makes a pair of fixed-size loops in the middle of a rope. Its advantage is that it is reasonably easy to untie after being exposed to load. It is one of the two [[tie in (climbing)|tie-in]] knots that are being taught by the [[German Alpine Club|German Alpine Club (DAV)]], generally being considered secure.<ref>{{cite web| archive-url=https://web.archive.org/web/20190622191125/https://www.klettern.de/sicherheit/duell-der-knoten-achter-versus-bulin/ | url=https://www.klettern.de/sicherheit/duell-der-knoten-achter-versus-bulin/ | title=Duell der Knoten: Achter versus Bulin (Duel of the knots: Figure-eight vs. Bowline) | date=28 April 2011 | publisher=Klettern.de | archive-date=Jun 22, 2019 | quote=Der gesteckte Achterknoten und der doppelte Bulin erfüllen diese Anforderungen. Es sind deshalb auch die beiden Einbindeknoten, die der Deutsche Alpenverein bei seinen Kursen lehrt, wobei der Achterknoten bei Einsteigern den Vorzug erhält, weil er sich leichter kontrollieren lässt.}}</ref><ref>{{cite web| url=https://www.alpenverein.de/chameleon/public/268f840e-d758-7682-4ccf-a49ce364ef60/160802_bergsteigen-allgemein-know-how-dav-summit-club_27512.pdf | archive-url=https://archive.today/20190624154323/https://www.alpenverein.de/chameleon/public/268f840e-d758-7682-4ccf-a49ce364ef60/160802_bergsteigen-allgemein-know-how-dav-summit-club_27512.pdf | archive-date=June 24, 2019 | title=Know-How Am Berg – Wesentliches zu Ausrüstung, Planung und Seiltechnik (engl: Know-how on the mountain – Essentials of equipment, planning and rope handling | publisher=DAV | quote=Der Achterknoten, in diesem Fall als „gesteckter Achter“ oder als „doppelter Bulin“ ausgeführt, dient als Anseilknoten. | access-date=July 4, 2019 | url-status=live }}</ref><ref>{{cite web| archive-url=https://web.archive.org/web/20181013112546/http://www.alpin.de/sicher-am-berg/6340/artikel_so_binden_sie_sich_richtig_ein_und_so_bitte_nicht_.html | url=http://www.alpin.de/sicher-am-berg/6340/artikel_so_binden_sie_sich_richtig_ein_und_so_bitte_nicht_.html | archive-date=Oct 13, 2018|title=So binden Sie sich richtig ein und so bitte nicht! (This is how you tie yourself in properly and this is how you don't do it!) | publisher=Alpin}}</ref>

==Dangers==
2011 testing shows that the knot might slip when only one loop is loaded. Cavers and canyoneers ought to fasten their cow-tail carabiner through both loops.<ref>{{cite web |url=http://efs.ffspeleo.fr/techniques/noeuds |title=Noeuds |access-date=2012-06-03 |url-status=dead |archive-url=https://web.archive.org/web/20120521195726/http://efs.ffspeleo.fr/techniques/noeuds |archive-date=2012-05-21 }} Video with genuine ''et voilà!'' ending {{in lang|fr}}</ref> European cavers widely advocate the use of [[Karash double loop|a figure eight twisted version of the bowline on a bight]].

==Applications==
This knot can be used to provide a toe hold in the middle of a rope; to make an emergency [[bosun's chair]];<ref>{{cite book |title=The Ashley Book of Knots |last=Ashley |first=Clifford W. |author-link=Clifford Warren Ashley |publisher=Doubleday |year=1944 |url=https://www.liendoanaulac.org/space/references/training/Ashley_Book_Knots.pdf |page=195 |archive-url=https://web.archive.org/web/20181219231529/https://www.liendoanaulac.org/space/references/training/Ashley_Book_Knots.pdf |archive-date=2018-12-19 }}</ref><ref>{{ }}</ref> and to create an upper rope "block" to make a crude purchase by threading the rope round an anchor point and then back up through the loop. It is sometimes used in [[sport climbing]] to tie into two anchor bolts independently. This knot is convenient when a dependable loop is required but neither end of the line is available. It's also commonly used as a seat while being hoisted as there are two secure loops as opposed to the traditional one loop bowline. In theory, this knot would make hoisting many people with one line possible. This knot is very popular in [[caving]] as it allows the load to be spread between two anchor points, reducing the stress placed on them and providing a backup should one fail. Commonly known as the Y-hang it allows for a free-hang descent and can be easily adjusted to avoid waterfalls or rub points.

As mentioned earlier, this knot can replace the figure-eight knot when tying into a climbing harness by tying a regular bowline knot and then re-threading it, such as is done with a figure eight knot. However, it is ''critical'' to use a [[Double fisherman's knot|strong backup knot]] with plenty of tail beyond the knot, as the knot may untie during long climbs.<!-- Source? The German "Alpenverein" recommends this knot as a save knot for tying in. --> The advantage of using this knot instead of the figure eight knot is that it can be easily untied after a severe fall.

==Technique==
The [[Bight (knot)|bight]] of rope is initially used to make a [[bowline]] in the usual way (picture on right). However, the bowline is ''not'' completed by going on round the standing end(s) and tucking the bight back down beside itself. Instead, the bight is opened up to allow the whole knot to pass through it (see picture on right). When tightened, the bight now embraces the pair of standing ends (see top picture)

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Image:BowlineBightStep1.jpg|1
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==Notes and references==
{{reflist}}

==See also==
* [[Double bowline]]
* [[List of knots]]

==External links==
*{{Animated Knots|bowlinebight|Bowline on a bight using rope}}
* {{cite web |date=2020-08-01 |author=Little Campfires |title=How to Tie a Bowline Knot (Plus Variations): Bowline on the Bight |url=https://youtube.com/watch?v=lS82ju__nyk?t=1339 |website=YouTube}}
* {{cite web |date=2023-09-11 |author=TheTautLine |title=Complete Guide to the Bowline Knot and its Most Important Variants: Bowline on a Bight |url=https://youtube.com/watch?v=QgewPTFzJzg?t=850 |website=YouTube}}

{{Knots}}

[[Category:Climbing knots]]
[[Category:Caving knots]]
[[Category:Double knots]]
[[Category:Multi-loop knots]]