Abseiling
Abseiling ( or /ˈɑːpzaɪl/; from German "abseilen", 'to rope down'), also known as rappelling (/ɹæˈpɛl/ or /ɹəˈpɛl/; from French "rappeler", 'to recall' or 'to pull through'), is a controlled descent off a vertical drop, such as a rock face, by descending a fixed rope. This technique is used by climbers, mountaineers, cavers, canyoners, search and rescue and rope access technicians to descend cliffs or slopes when they are too steep and/or dangerous to descend without protection. Many climbers use this technique to protect established anchors from damage. Rope access technicians also use this as a method to access difficult-to -reach areas from above for various industrial applications like maintenance, construction, inspection and welding. To descend safely, abseilers use a variety of techniques to increase the friction on the rope to the point where it can be controlled comfortably. These techniques range from wrapping the rope around their body (e.g. The Dülfersitz) to using a custom-built device like a rack. Practitioners choose a technique based on speed, safety, weight and other circumstantial concerns. In the United States, the term "rappelling" is used nearly exclusively. In the United Kingdom, both terms are understood, but "abseiling" is strongly preferred. In Australia , New Zealand and Canada, the two terms are used interchangeably. Globally, the term "rappelling" appears in books written in English more often than "abseiling". History. The origin of the "term" rappel in reference to the technique is attributed by circa 1944. Frison in turn attributed the "technique" of abseiling to , a Chamonix guide who lived from 1840 to 1925. Charlet originally devised the technique during a failed solo attempt of Petit Dru in 1876. After many attempts, some of them solo, he managed to reach the summit of the Petit Dru in 1879 in the company of two other hired  Chamonix guides, Prosper Payot and Frédéric Folliguet. During that ascent, Charlet mastered the technique. Application. Abseiling is used in a number of applications, including: Safety. Abseiling can be dangerous, and presents risks, especially to unsupervised or inexperienced abseilers. According to German mountaineer Pit Schubert, about 25% of climbing deaths occur during abseiling, most commonly due to failing anchors. An analysis of American Alpine Club accident reports shows that this is followed by inadequate safety backups and rappelling off the ends of ropes. Environmental concerns. Abseiling is prohibited or discouraged in some areas, due to the potential for environmental damage and/or  conflict with climbers heading upwards, or the danger to people on the ground.