rescue, use a Prusik hitch as a 'ratchet' or progress capture device. A Prusik with a Prusik minding pulley is used to hold a load while tensioning a line. The pulley advances the Prusik up the line and prevents it from going back out. This can be used to raise a patient or tension a highline for a Tyrolean traverse, or in boat-on-tether and similar rescue operations. Handcuffsthumb|Bosun's or Prusik handcuffs A length of rope that has been tied so that the Prusik knot is tied around itself leaving two large loops can be quickly used as handcuffs by slipping the loops around the detainee's hands and pulling the running ends tight and securing them with a square knot. When the detainee attempts to pull his hands apart, the Prusik tightens in the same way as when it is tied to another rope. To create Prusik handcuffs, tie a loose Prusik around one of your fingers and then slip it off, leaving the knot shape intact. Then slip the free ends of the rope through the "hole" in the knot where your finger used to be. Alternatively, use a handcuff knot, which is the more usual knot to accomplish this task. Testing rigs for tensile strength and pull force: RepRap researchers have used the Prusik knot to secure a fiber in order to measure the pull force of an extruder mechanism and estimate the tensile strength of a fiber. When to carry (climbing, kayaking) All sorts of climbers carry Prusiks as standard equipment "just in case". Prusiks are unlikely to be needed on short climbs where the climber can be readily lowered to the ground; conversely, they may prove useful where the climber cannot be lowered, for instance from a high cliff or due to a hazard underneath the climber. Prusiks can be tied using other climbing equipment, such as slings already carried by the climber. Three loops allow the climber to pass a knot in the rope, a difficult task without a third loop. Kayaking: For kayaking, a Prusik can be used in a similar way as in climbing; for rescuing people and equipment from a river, a Prusik or two with a set of pulleys to create a Z-drag is preferred. Camping, hiking and bushcraft: The Prusik Knot can be used to attach a tarpaulin or shelter to a ridge line, as they can easily be slid along