Difference between revisions of "AY Honors/Knot/Prusik"

Latest revision as of 13:43, 8 September 2021

Prusik knot

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 20 to 100 cm 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. 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.

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.

How to tie:
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.

Step 1
Step 2
Step 3
Step 4
Locked while holding tension.
Slides readily without tension.

@@ Line 1: / Line 1: @@
-A prussik or prussik knot is a specialist advanced climbing technique allowing a loop of weightbearing material with a fine diameter (usually around 6mm) to be tied to a wider line (usually around 9-11mm) in a fashion that will allow it to be moved along the line.  These knots can be applied even when the wider line is under tension and have multiple applications.
+<noinclude><translate><!--T:5-->
+</noinclude>
-Equipment
+{{Knot
-A prussik knot is applied using a loop of finer cord with tied ends (usually with a fishermans knot) or sown sling of around 60cm in length.  These are usually then referred to as prussik loops and most experienced climbers carry a pair of these attached to their harness.
+| name=Prusik knot
+| image= Prusikhowto4.jpeg
-Knots
+| 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''').
-The three major prussik knots are:
+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.
+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.
-Kleimheist
+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.
-Auto-bloc
+| tying_instructions =
-(incomplete information)
+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>
-These are simple knots involving wrapping the loop around the rope 3-5 times (depending on the materials) and then (usually) back through it's self.  When the loop is weighted the turns tighten against the main rope preventing movement.  When weight is removed the prussik loop can be slid along the line by placing a hand directly on the turns and pushing.
+Image:Prusikhowto1.saa.jpeg|Step 1
+Image:Prusikhowto2.saa.jpeg|Step 2
-Applications
+Image:Prusikhowto3.saa.jpeg|Step 3
-Abseiling: A prussik loop can be used to protect during the descent, placed below a descender device and with one hand on it for controll it will act as an automatic dead mans handle should the climber be incapatited or require the use of their hands.
+Image:Prusikhowto4.jpeg|Step 4
+Image:Prusikhowto5.jpeg|Locked while holding tension.
-"Prussiking" or ascending the line:  Two prussiks used in tandem can allow the experienced user to climb a rope that is fixed above them with minimal effort.  One prussik is attached to the "abseil loop" sown 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 waist loop up and "sit" down on it.  Once sat they can slide the foot loop up the rope and repeat the process.
+Image:Prusikhowto6.saa.jpeg|Slides readily without tension.
+</gallery>
-Tying off:  When belaying the hands are required on the line at all times and the belayer can not move away from the rope.  Should the climber become in someway incapacitated and are in a position where they cannot be safely lowered to the ground then the belayer cannot come to their aid without appropriate skills and equipment.  A special knot at this point will alow a belayer to "tie off" the belay plate a free the use of their hands.  Correct applications of prussik loops will then alow them selves to move away from the belay device without endagering the climber.  They can now affect a rescue or get help.
+}}
+<noinclude></translate></noinclude>
-WARNING:  Climbing is a sport with inherrent danger.  The preceding techniques are general descriptions only and should only be practiced in a controlled environment with experienced instruction.  It is recomended that you attend an official training course with certified instructors.
+{{#ifeq:{{#titleparts:{{PAGENAME}}|1}}|Adventist Youth Honors Answer Book|[[Category:Adventist Youth Honors Answer Book|{{SUBPAGENAME}}]]}}<!-- Use in [[knots]] -->
-Please feel free to add to his script as it is far from complete.