Ascender
An ascender (sometimes also referred to as a rope clamp ) is an item of equipment for climbing that allows a climbing rope to slide in one direction without great effort, but blocks it in the other direction.
Safety requirements for rope clamps and the associated test methods are described in European Standard (EN) 567.
functionality
Most ascenders have a moving part that is pressed against the rope by a spring (exception: Tibloc from Petzl ). It also gets stuck under load. Mostly small teeth are attached to the clamping surface, which penetrate between the fibers of the rope, but without damaging the rope. So the clamping effect is given even with iced ropes. The ascender also has a hole for attaching a carabiner . A carabiner can be hooked into the upper hole to prevent the rope from slipping sideways. In order to be able to release the ascender from the rope and to cancel the clamping effect (e.g. when dismounting), there is a small lever. Ascenders often also have a large handle with which they can be pushed up the rope and which can also be used to pull yourself up on the rope.
A clamping knot such as the Prusik knot can be used as a replacement for an ascender .
application
The main application is the so-called Jümarn (English jumaring , the term is derived from the Swiss company Jümar and the ascender of the same name), i.e. H. ascending the rope with two rope clamps. Here, one ascender is attached to the climbing harness , and a second to a sling that you step into with your foot. Alternately, the climber now climbs into the step loop and pushes the ascender on the climbing harness up on the rope, which has been relieved of pressure, and then sits in the climbing harness and pushes the ascender up on the step loop.
An ascender can also be used for self-belaying when climbing solo. The prerequisite is that the route to be climbed can be reached from above and thus provided with a fixed rope, which is often possible in climbing gardens and gyms. A use of ascenders in lead climbing is ruled out, as the case possible loads exceed with in extreme cases more than 10 kN the typical break load of standard terminals (3-5 kN) wide.
Rope clamps are also used as a backstop when building pulley blocks .
See also
literature
- DIN EN 567: 2013: Mountaineering equipment - Rope clamps - Safety requirements and test methods; German version of EN 567: 2013, edition 2013-06
- Pit Schubert: Jümars and Pulleys. Standard testing of rope clamps and rope pulleys . In: Mountaineering . No. 1 , 2007, p. 78–82 ( bergundstieg.at [PDF; 169 kB ]).
