Water knot

Last updated
Water knot
Water-knot-webbing-tight-ABOK-296.jpg
NamesWater knot, Tape knot, Ring bend, Grass knot, Overhand follow through
Category Bend
Related Overhand knot, beer knot, overhand bend
Typical useTo join webbing for climbing
CaveatEnds should be left long, knot should be tightened and inspected before each use. Difficult to untie.
ABoK #296, #1412
Instructions animatedknots.com

The water knot (also tape knot, ring bend, grass knot, or overhand follow-through) is a knot frequently used in climbing for joining two ends of webbing together, for instance when making a sling.

Contents

Tying

Water knot before tightening Water-knot-webbing-loose-ABOK-296.jpg
Water knot before tightening

It is tied by forming an overhand knot in one end and then following it with the other end, feeding in the opposite direction.

The ends should be left at least 7.5 centimetres (3.0 in) long and the knot should be "set" by tightening it with full body weight. The ends can be knotted, taped or lightly sewn to the standing parts to help prevent them from creeping back into the knot. [1]

Uses

The knot can be used for joining flat materials such as leather or tape. [2]

Security

Once tied, for additional security each end should be tied in a double overhand stopper knot around the other standing end.

Some testing has shown that the water knot, in certain conditions, can slip very slightly but very consistently, with cyclic loading and unloading at relatively low forces; it is the tail on the exterior that slips (this would be the blue tail in the image presented here). In tests using 9/16 in (14.3 mm) tubular nylon webbing, repeated loading and unloading with 250 lbs (113 kg) caused one of the 3 in (76 mm) tails to work back into the knot in just over 800 loading cycles. Another test showed similar results for Spectra tape (but not for new, 1-inch tubular nylon). And yet the knot can be loaded to rupture without slippage. These results validate the need to leave adequate tails and inspect water knots before each use. With single overhand knot safeties on either end, the combination eventually seized and the slipping stopped. [3]

Although used extensively in climbing and caving, there is some opinion that the water knot is unsafe. According to Walter Siebert, several deaths have been reported due to failure of this knot (although, as in many failed-knot cases, the actual mechanism of failure is unknown, and only conjecture can be inferred). He demonstrates in a video how easily the knot can pull loose if snagged. [4] Siebert references an article from Pit Schubert in 1995 that details many deaths investigated where the water knot was used with webbing and failed. Schubert drew the conclusion after reviewing the remaining webbing and the sites where these falls took place that the knot can open if it catches on an edge or any protrusion.

However, these men do not realize that this uncommon vulnerability can lead to trouble only if (a) the knot will move much under load --so to pull out enough tail to fail--, and the exterior strand must be loaded from the top --so that a downwards pull by the interior strand (the red one, as shown here) will pull away from the snagged exterior strand. Orienting the knot in the opposite way and placing it high, removes these failure conditions. [5]

In Germany, the knot is sometimes called Todesknoten, which means death knot. [6]

Variations

The figure-8 water knot (or figure-8 bend or Flemish bend) [7] is based upon a figure-8 (or Flemish) knot instead of an overhand knot. It is easier to untie.

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.

Overhand knot

The overhand knot, also known as a a knot and half knot, is one of the most fundamental knots, and it forms the basis of many others, including the simple noose, overhand loop, angler's loop, reef knot, fisherman's knot, and water knot. The overhand knot is a stopper, especially when used alone, and hence it is very secure, to the point of jamming badly. It should be used if the knot is intended to be permanent. It is often used to prevent the end of a rope from unraveling. An overhand knot becomes a trefoil knot, a true knot in the mathematical sense, by joining the ends.

Fishermans knot

The fisherman's knot is a bend with a symmetrical structure consisting of two overhand knots, each tied around the standing part of the other. Other names for the fisherman's knot include: angler's knot, English knot, halibut knot, waterman's knot.

Figure-eight knot Type of stopper knot used in sailing and climbing

The figure-eight knot or figure-of-eight knot is a type of stopper knot. It is very important in both sailing and rock climbing as a method of stopping ropes from running out of retaining devices. Like the overhand knot, which will jam under strain, often requiring the rope to be cut, the figure-of-eight will also jam, but is usually more easily undone than the overhand knot.

The figure-eight or figure-of-eight knot is also called the Flemish knot. The name figure-of-eight knot appears in Lever's Sheet Anchor; or, a Key to Rigging. The word "of" is nowadays usually omitted. The knot is the sailor's common single-strand stopper knot and is tied in the ends of tackle falls and running rigging, unless the latter is fitted with monkey's tails. It is used about ship wherever a temporary stopper knot is required. The figure-eight is much easier to untie than the overhand, it does not have the same tendency to jam and so injure the fiber, and is larger, stronger, and equally secure.

A whipping knot or whipping is a binding of marline twine or whipcord around the end of a rope to prevent its natural tendency to fray.

Figure-eight loop

Figure-eight loop is a type of knot created by a loop on the bight. It is used in climbing and caving where rope strains are light to moderate and for decorative purposes.

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.

Climbing harness

A climbing harness is an item of climbing equipment for rock-climbing, abseiling, or other activities requiring the use of ropes to provide access or safety such as industrial rope access, working at heights, etc. A harness secures a person to a rope or an anchor point.

Webbing

Webbing is a strong fabric woven as a flat strip or tube of varying width and fibres, often used in place of rope. It is a versatile component used in climbing, slacklining, furniture manufacturing, automobile safety, auto racing, towing, parachuting, military apparel, load securing, and many other fields.

Rock-climbing equipment

A wide range of equipment is used during rock or any other type of climbing that includes equipment commonly used to protect a climber against the consequences of a fall.

Blood knot

A blood knot is a bend knot most usefully employed for joining sections of monofilament nylon line while maintaining a high portion of the line's inherent strength. Other knots used for this purpose can cause a substantial loss of strength. In fly fishing, this serves to build a leader of gradually decreasing diameter with the castable fly line attached at the large diameter end and the fly or hook at the small diameter end. The principal drawback to the blood knot is the dexterity required to tie it. It is also likely to jam, which is not a concern in fishing line, which is no great loss to cut, but may be a concern in normal rope. "Blood knot" may refer to "a double overhand knot tied in a cat-o'-nine-tails."

The barrel knot, called blood knot by Keith Rollo, is the best bend there is for small, stiff or slippery line. The ends may be trimmed short and the knot offers the least resistance possible when drawn through water.

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.

Rope splicing Rope merging

Rope splicing in ropework is the forming of a semi-permanent joint between two ropes or two parts of the same rope by partly untwisting and then interweaving their strands. Splices can be used to form a stopper at the end of a line, to form a loop or an eye in a rope, or for joining two ropes together. Splices are preferred to knotted rope, since while a knot typically reduces the strength by 20–40%, a splice is capable of attaining a rope's full strength. However, splicing usually results in a thickening of the line and, if subsequently removed, leaves a distortion of the rope. Most types of splices are used on 3-strand rope, but some can be done on 12-strand or greater single-braided rope, as well as most double braids.
While a spliced 3-strand rope's strands are interwoven to create the splice, a braided rope's splice is constructed by simply pulling the rope into its jacket.

Beer knot

A beer knot is a bend used to join tubular webbing. Its most common application is in constructing slings used in rock climbing. Compared with the water knot, it has the advantages of a higher strength, smaller profile, and a cleaner appearance due to the lack of free-hanging tails. However, the beer knot can be more difficult to tie than the water knot, and one of the tails is hidden from view, making safety checks for adequate tail length more difficult.

Offset overhand bend

The offset overhand bend is a knot used to join two ropes together. The offset overhand bend is formed by holding two rope ends next to each other and tying an overhand knot in them as if they were a single line. Due to its common use in several fields, this bend has become known by many names, such as thumb knot, openhand knot, one-sided overhand knot or flat overhand bend (FOB), though the terms "one-sided" and "flat" are considered incorrect.

Eye splice

The eye splice is a method of creating a permanent loop in the end of a rope by means of rope splicing.

Ashleys bend

Ashley's bend is a knot used to securely join the ends of two ropes together. It is similar to several related bend knots which consist of two interlocking overhand knots, and in particular the alpine butterfly bend. These related bends differ by the way the two constituent overhand knots are interlocked.

Yosemite bowline Loop knot often perceived as having better security than a bowline

A Yosemite bowline is a loop knot often perceived as having better security than a bowline. It has been pointed out that if the knot is not dressed correctly, it can potentially collapse into a noose, however testing reveals this alternative configuration to be strong and safe as a climbing tie-in.

Offset figure-eight bend Dangerous knot

The offset figure-eight bend or flat figure-eight bend or abnormal figure-eight bend is a poor knot that has been implicated in the deaths of several rock climbers. The knot may invert itself under load, as shown in the figure, and this can happen repeatedly. Each inversion reduces the lengths of the tails. If the tails are used up completely, the knot comes undone.

References

  1. Craig Luebben, Knots for Climbers (Evergreen, Colorado: Chockstone Press, 1993), 19.
  2. John 'Lofty' Wiseman SAS Survival Handbook, Revised Edition; William Morrow Paperbacks (2009) ISBN   978-1875900060
  3. Tom Moyer, Water Knot Testing , 1999 International Technical Rescue Symposium, 1999. accessed 2007-04-07.)
  4. https://www.youtube.com/watch?v=mXe-8GmS08k
  5. Siebert, Walter (2002). "Der Band(schlingen)knoten - eine beinahe unendliche Geschichte" [The Water Knot - an almost never-ending story](PDF) (in German). Archived from the original (PDF) on 4 August 2019. Retrieved 20 May 2020.
  6. Walter Siebert (2007), Deutscher Alpenverein; Österreichischer Alpenverein; Schweizer Alpen-Club (eds.), "Warten wir noch ein paar Tote ab" (PDF), bergundsteigen (in German), Innsbruck (2/2007), pp. 38-45, retrieved 5 March 2008
  7. Grogono, Alan W. Grogono (Grog), David E. Grogono, Martin J. "Knots by Grog References - Knots Sources - Ashley Book of Knots". www.animatedknots.com. Retrieved 19 April 2018.