Jump to content

Figure-eight loop

From Wikipedia, the free encyclopedia
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
Figure-eight loop
NamesFigure-eight loop, Flemish loop
CategoryLoop
Relatedfigure-eight knot, flemish bend, Figure-of-nine loop, spider hitch
ReleasingJamming
Typical useclimbing, caving
Caveatjams
ABoK#1047, #531
Instructions[1]

Figure-eight loop (also figure-eight on a bight, figure-eight follow-through, figure-eight retrace, Flemish loop, or Flemish eight) is a type of knot created by a loop on the bight. It is used in climbing and caving.

The Flemish loop or figure-eight loop is perhaps stronger than the loop knot. Neither of these knots is used at sea, as they are hard to untie. In hooking a tackle to any of the loops, if the loop is long enough it is better to arrange the rope as a cat's paw.

— The Ashley Book of Knots[1]

The double figure eight is used to put a loop in the end of a rope, or around an object. It is relatively easy to tie and is secure, but can become difficult to untie after heavy loading, and can jam badly in any rope type.

Tying methods

On a bight

A figure-of-eight loop tied using the follow-through method.

A figure-eight loop is created by doubling the rope into a bight, then tying the standard figure-eight knot.

In climbing, this knot is used to save time when repeatedly attaching the rope to climbing harnesses, using locking carabiners, such as when a group of people are climbing on the same top-rope.[2]

Follow-through

A well-dressed figure-eight follow-through after tightening

Alternatively, to tie the knot directly around an object, the follow-through method must be used.

  • Tie a regular figure eight knot with a significant amount of extra tail.
  • Loop the tail around the object.
  • Thread the tail back through the figure eight to create a normal looking figure eight on a bight.

Climbing

This is the standard method for attaching a rope to a climbing harness.[3][4]

Often an additional strangle knot (which is half of a double fisherman's knot) "backup knot" is tied in the tail of the figure 8.[5][6][7][8] This is not required for the knot's integrity during climbing,[3][2][9][10][11][12] but could prevent ring-loading failure if belaying from the rope loop (instead of a dedicated belay loop).[13][14] It also ensures that adequate tail length has been included, and gets excess tail out of the way.[15] If the finish knot is not included, the tail should be 4 to 8 inches long.[3][16][17][18][10] The tail can also be tucked back into the knot, called a "Yosemite finish" or "Yosemite tuck".[19] This holds the bottom loop open, making the knot easier to untie after falling, but also making it weaker in a ring-loading configuration.[20][21]

The diameter of the loop should be kept small to avoid being caught on protrusions while falling, or clipped into accidentally while lead climbing.[3] A well-dressed knot has a symmetrical appearance, with the strands parallel through each curve.[3][22]

See also

References

  1. ^ Ashley, Clifford W. (1944). The Ashley Book of Knots, p.190. Doubleday. ISBN 0-385-04025-3.
  2. ^ a b Fitch, Nate; Funderburke, Ron (2015). Climbing: Knots. Rowman & Littlefield. p. 32. ISBN 9781493015061. Tying a double overhand or barrel knot in front of the figure 8 follow through does not alter the failure mechanism of the knot. It simply adds another step to an already secure knot.
  3. ^ a b c d e Gaines, Bob; Martin, Jason D. (2014). Rock Climbing: The AMGA Single Pitch Manual. Rowman & Littlefield. ISBN 9781493009626. When tied correctly, the knot is tight, with a 5- to 8-inch tail ... Tie the figure eight so that its loop is about the same diameter as your belay loop. The figure eight knot does not require a backup knot.
  4. ^ Ritter, Max (2016-07-20). "Learn to Climb: Tie in With a Figure Eight Follow-Through Knot". Climbing Magazine. Retrieved 2018-07-13.
  5. ^ Mountaineering : the freedom of the hills. Eng, Ronald C., Van Pelt, Julie. Mountaineers Books. 2010. p. 141. ISBN 9781594851384. OCLC 607322876. For instance, the overhand knot can be used to secure rope ends after ... a rewoven figure eight (fig. 9-4c). ... The rewoven figure eight is finished off by tying an overhand knot in the loose end of the rope.{{cite book}}: CS1 maint: others (link)
  6. ^ Timothy W. Kidd, Jennifer Hazelrigs, ISBN 978-0-7360-6802-4 Rock climbing. Wilderness Education Association (U.S.) "There is great debate about whether the [Figure Eight] knot is finished at this point. Some people think stopping at this point is sufficient; others believe that since your life depends on this knot, you should back it up. ...The most common backup knot is a [strangle knkot]."
  7. ^ Raleigh, Duane (1998). Knots & Ropes for Climbers. Stackpole Books. p. 28. ISBN 978-0-8117-2871-3. make certain you leave a long tail, and finish this with a Double Fisherman's
  8. ^ Owen, Peter (1993). Knots. Courage Books. ISBN 978-1-56138-225-5. A stopper knot must be added when the threaded figure eight loop is used to tie on a line.
  9. ^ Martin, Jason D. "The Figure-Eight Follow-Through". American Alpine Institute. Retrieved 2018-07-13. The reality of the so-called 'back-up knot'is that it is not necessary.
  10. ^ a b Delaney, Richard (November 7, 2018). "Members: Fig8 tail length". RopeLab Online. Retrieved 2020-05-28. If correctly tied, dressed, and set then it does not need an additional stopper knot to secure the tail. ... I would recommend allowing a tail of 100mm.
  11. ^ Luebben, Craig (2011). Knots for Climbers. Rowman & Littlefield. ISBN 978-0-7627-6858-5. The figure eight follow-through does not require a backup ... but it can't hurt to use one
  12. ^ Vogel, Todd (2017-10-26). "Knot and cord strength: answers to common questions" (PDF). Earth First! Climbers Guild. Archived from the original (PDF) on 2017-10-26. Retrieved 2020-06-10. You do not need a backup knot behind a figure eight tie-in knot nor should students be taught that 'messy' knots are weaker than 'correct' knots.
  13. ^ Geldard, Jack (1 July 2008). "Belaying – 'Rope Loop' or 'Belay Loop'?". UKClimbing. Retrieved 2020-06-13. Make sure your knot is well tied, tight and has a stopper knot. Adding a stopper knot adds another link to the safety chain.
  14. ^ rgold (16 Feb 2017). "Is a stopper knot necessary with a figure-of-8?". UKClimbing Forums. Retrieved 2020-06-13. a situation to be aware of is when the climber belays off the rope loop rather than the harness belay loop
  15. ^ "Is a safety knot on your figure-eight a necessity?". Mountain Project. Retrieved 2018-07-13.
  16. ^ "Dynamic climbing ropes manual: Precautions for use" (PDF). Mammut.com. min. 10cm
  17. ^ "Dynamic Rope Manual: Fig. 2: Terminal connections" (PDF). Edelrid. min. 10 cm
  18. ^ "Dynamic: Fig. 4". Beal ropes. 10 cm
  19. ^ Fitch, Nate; Funderburke, Ron (2015). Climbing: Knots. Rowman & Littlefield. p. 33. ISBN 978-1-4930-1506-1.
  20. ^ "The Figure-Eight Follow-Through". American Alpine Institute. Retrieved 2020-06-13. may seriously weaken the knot if you use the inside of the knot as a belay loop
  21. ^ Dahlberg, Robin. "Cross load test of common climbing knots". Vimeo. 0:36–1:45. Retrieved 2020-06-10.
  22. ^ JB (2018-07-17). "The Well-Dressed Figure Eight Knot: Start Hard, Finish Easy". Fox Mountain Guides & Climbing School. Retrieved 2020-05-28.
Retrieved from "https://en.wikipedia.org/enwiki/w/index.php?title=Figure-eight_loop&oldid=1246214227"