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| | {{Knot | | {{Knot |
| | | name=Prusik knot | | | name=Prusik knot |
| − | | image= prusikhowto4.saa.jpeg | + | | image= Prusikhowto4.jpeg |
| − | | use = A '''Prusik (aka Prussik or Prussic)''' is a friction hitch used in climbing, canyoneering, caving, rope rescue and by arborists to grab a rope (sometimes referred to as a ''rope-grab''). The term '''Prusik''' is used both for the knot, for the loops of cord, and for the action ('''to prusik'''). | + | | use = A '''Prusik (aka Prussik or Prussic)''' is a friction hitch used in climbing, canyoneering, caving, rope rescue and by arborists to grab a rope (sometimes referred to as a ''rope-grab''). The term '''Prusik''' is used both for the knot, for the loops of cord, and for the action ('''to prusik'''). |
| − | | + | A Prusik rope is a circular loop with a circumference of {{units|20 to 100 cm|8-40 inches}} depending on its intended use. Two Prusik ropes are tied to another rope which is anchored above. When the Prusik knot is under tension, it grabs the rope to which it is tied. When not under tension, it is easily moved. The climber places one foot into each loop, and shifts all of his or her weight to one of them, releasing the tension on the other. The rope without tension is then slid upwards on the vertical rope. The climber then shifts his or her weight to the other loop and slides the first one up. This is repeated until the rope has been ascended. |
| − | A Prusik rope is a circular loop with a circumference of {{units|20 to 100 cm|8-40 inches}} depending on its intended use. Two Prusik ropes are tied to another rope which is anchored above. The climber places one foot into the bottom of the two loops and slides the top one up the vertical rope. The other foot is then placed in the top loop and the bottom loop is moved upwards. By repeating these maneuvers, the climber may ascend the rope. When the Prusik knot is under tension, it grabs the rope to which it is tied. When not under tension, it is easily moved. | + | Prusiks will work around two ropes, even two ropes of different diameters. Prusiks provide a high-strength and relatively fail-safe (i.e., they will slip before damaging the rope or breaking) attachment, and are used in some rope-rescue techniques. Prusiks are good to use in hauling systems where multiple rope-grabs may be needed, and where mechanical rope-grabs are not available. |
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| − | Prusiks will work around two ropes, even two ropes of different diameters. Prusiks provide a high-strength and relatively fail-safe (i.e., they will slip before damaging the rope or breaking) attachment, and are used in some rope-rescue techniques. Prusiks are good to use in hauling systems where multiple rope-grabs may be needed, and where mechanical rope-grabs are not available. | |
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| | Although the Prusik Climb technique may be called old-school by some, the US Army still includes it in its annual Best Ranger competition. Rangers in the competition routinely make it up a 90 foot rope in under a minute. | | Although the Prusik Climb technique may be called old-school by some, the US Army still includes it in its annual Best Ranger competition. Rangers in the competition routinely make it up a 90 foot rope in under a minute. |
| | | tying_instructions = | | | tying_instructions = |
| − | The Prusik is tied by wrapping the prusik loop around the rope a number of times (depending on the materials, but usually 3-5 times), and then back through itself, forming a barrel around the rope, with a tail hanging out the middle. When the tail is weighted the turns tighten around the main rope and grab. When weight is removed the loop can be slid along the rope by placing a hand directly on the barrel and pushing. The trick is, if it grabs well, then it is hard to slide along the rope. '''Breaking''' the Prusik free from the rope after it has been weighted can be difficult, and is easiest done by pushing the ''bow'', being the loop of cord which runs from the top wrap, over the knot to the bottom wrap, along the tail a little. This loosens the grip of the hitch and makes movement easier. | + | The Prusik is tied by wrapping the prusik loop around the rope a number of times (depending on the materials, but usually 3-5 times), and then back through itself, forming a barrel around the rope, with a tail hanging out the middle. When the tail is weighted the turns tighten around the main rope and grab. When weight is removed the loop can be slid along the rope by placing a hand directly on the barrel and pushing. The trick is, if it grabs well, then it is hard to slide along the rope. '''Breaking''' the Prusik free from the rope after it has been weighted can be difficult, and is easiest done by pushing the ''bow'', being the loop of cord which runs from the top wrap, over the knot to the bottom wrap, along the tail a little. This loosens the grip of the hitch and makes movement easier. |
| | <gallery> | | <gallery> |
| − | Image:prusikhowto1.saa.jpeg|Step 1. | + | Image:Prusikhowto1.saa.jpeg|Step 1 |
| − | Image:prusikhowto2.saa.jpeg|Step 2. | + | Image:Prusikhowto2.saa.jpeg|Step 2 |
| − | Image:prusikhowto3.saa.jpeg|Step 3. | + | Image:Prusikhowto3.saa.jpeg|Step 3 |
| − | Image:prusikhowto4.saa.jpeg|Step 4.]] | + | Image:Prusikhowto4.jpeg|Step 4 |
| − | Image:prusikhowto5.saa.jpeg|Locked while holding tension.]] | + | Image:Prusikhowto5.jpeg|Locked while holding tension. |
| − | Image:prusikhowto6.saa.jpeg|Slides readily without tension.]] | + | Image:Prusikhowto6.saa.jpeg|Slides readily without tension. |
| | + | </gallery> |
| | }} | | }} |
| − | | + | <noinclude></translate></noinclude> |
| − | Many materials may be used to tie a prusik. The webbing illustrated is one choice, but many find round cord to work better. In many instances, adding more wraps increases the grip.
| + | {{#ifeq:{{#titleparts:{{PAGENAME}}|1}}|Adventist Youth Honors Answer Book|[[Category:Adventist Youth Honors Answer Book|{{SUBPAGENAME}}]]}}<!-- Use in [[knots]] --> |
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| − | [[Image:prusikthreeturn.saa.jpeg|thumb|none|250px|A variation of the Prusik knot with additional friction.]]
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| − | == Applications ==
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| − | In addition to being a useful rope-grab for rope-rescue applications, Prusiks are popular for:
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| − | *'''"Rappel Backup"/"Self-Belay Below The Device":''' A Prusik is placed below the descender and controlled with the brake hand. It acts as an automatic 'dead man's handle' should the climber be incapacitated or require the use of both hands. Careful setup of the [[rappel]] backup is critical, or it will not work. An AutoBloc knot is most widely used in this application. This technique is used by some rappellers, and not by others.
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| − | *'''"Rappel Backup"/"Self-Belay Above The Device":''' A Prusik is placed above the descender and controlled with the hand not being used as the brake hand. This configuration allows for easier and faster transition from rappeling to climbing the rope, but can also result in the Prusik locking tight as the amount of friction required to hold the load at that point is far higher than that experienced by a ''self-belay below the device''.
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| − | *'''"Prusiking" or ascending the line:''' Two prusiks used in tandem can be used to climb a fixed rope. One prussik is attached to the "belay loop" sewn onto the front of a harness and the other is attached to a longer length of cord reaching to one foot. With one loop attached to the rope above the other the climber can then stand up in the foot loop, slide the prusik hitch of the waist loop further up the rope and then "sit" down on it. Once sitting, they can slide the foot loop up the rope and repeat the process.
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| − | *'''"Escaping the Belay": ''' In a lead-climbing situation, should the belayed climber become incapacitated in a position where they cannot be safely lowered to the ground, the belayer must ''escape the belay'' in order to effect rescue. With the belay rope locked off with one hand, the belayer can tie a prusik to the rope with the other hand, and transfer the load to a fixed anchor; thus allowing them to effect rescue or go get help.
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| − | *'''Various Rescue Applications''' Rope rescue teams such as in [[swiftwater rescue]] or in high angle technical rescue use a Prusik hitch as a 'ratchet' or 'progress capture device'. A prussik with a prussik minding pulley is used to hold a load while tensioning a line. The pulley advances the prussik up the line and prevents it from going back out. This can be used to raise a patient or tension [[Highlining|highline]] for a [[Tyrolean traverse]], or in ''boat-on-tether'' and similar rescue operations.
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| − | == When To carry (climbing) ==
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| − | Prusik cords are carried by some climbers and not carried by others. The decision over whether or not to carry prusiks is a matter of personal taste and training. Prusiks are unlikely to be needed on short climbs where the climber can be lowered to the ground; conversely they may prove useful where the climber cannot be lowered (either due to the height of the cliff or due to a hazard underneath the climber). Contrary to popular belief, prusiks are not the sole preserve of [[Traditional climbing|Trad Climbers]] - [[Sport climbing|Sport Climbers]] on [[Multi-pitch climbing|multi-pitch]] routes sometimes also carry prusiks.
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| − | Prusiks can be improvised from other climbing equipment, such as slings, already carried by the climber. Some climbers carry prusik-specific cords so that they are always easily and quickly available in an emergency.
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| − | Some sources recommend that three prusik loops be carried. The logic being that two are required to ascend a rope, and the third allows for one to be lost, damaged, or dropped. Three loops also allow the climber to pass a knot in the rope should the need arise, a difficult task without a third loop.
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| − | ==References==
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| − | * [[The Ashley Book of Knots]] discusses a knot of similar structure in the entry for drawing #1763
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| − | ==External links==
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| − | *[http://ozultimate.com/canyoning/knots/prusik/ Prusik Knot at OZultimate.com canyoning] with good pictures showing how it is tied.
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| − | *[http://fmg-www.cs.ucla.edu/geoff/prusik_knot.html Prusik Knot used in Sailing] for climbing a mast, with other notes.
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| − | *[http://www.iland.net/~jbritton/Friction%20Hitches.html Many Varieties of Friction Hitches]
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| − | *[http://storrick.cnchost.com/VerticalDevicesPage/Misc/RappelSafetyPost.html Discussion of Rappel Backups - Pros and Cons]
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| − | *[http://www.outdooridiots.com/features/200605/prusik/prusik.asp A detailed article, good pictures, several prusiks and ideas shown.]
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| − | [[Category:Hitch knots]]
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| − | [[Category:Climbing knots]]
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| − | [[cs:Prusíkův uzel]]
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| − | [[de:Prusikknoten]]
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| − | [[fr:Nœud de Prusik]]
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| − | [[it:Nodo prusik]]
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| − | [[nl:Prusikknoop]]
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| − | [[pl:Prusik]]
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| − | [[ru:Прусик]]
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| − | [[sv:Prusikknop]]
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