Abseiling

Abseiling (/ˈæbseɪl/ AB-sayl or /ˈɑːpzaɪl/ AHP-zyle; from German abseilen 'to rope down'), also known as rappelling (/ˈræpɛl/ RAP-pell or /rəˈpɛl/ rə-PELL; from French rappeler 'to recall, to pull through'), is the controlled descent of a steep slope, such as a rock face, by moving down a rope. When abseiling, the person descending controls their own movement down a static or fixed rope, in contrast to lowering off, in which the rope attached to the person descending is paid out by their belayer.
The 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 technique) to using custom-built devices like a rack or a figure of 8. Practitioners choose a technique based on speed, safety, weight and other circumstantial concerns.
In the United States, the term "rappelling" is used. In the United Kingdom, both terms are understood, but "abseiling" is more common. 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".
Abseiling has existed, both using body abseil and descenders for centuries, with body abseiling being mentioned in the late 1400s, and descenders being described in the early 1600s.
The origin of the term rappel in reference to the technique is attributed by Mountaineering author Roger Frison-Roche [fr; ca; de; eo; pt] circa 1944. Frison-Roche in turn attributed the technique of rappelling to Jean Charlet-Straton [fr], a Chamonix guide who lived from 1840 to 1925. However, at the time, the term rappel meant to use a doubled rope that could be pulled down afterwards, and did not necessarily refer to abseiling, and while Frison-Roche may have used a doubled rope technique, he did not use an abseiling technique devised by Charlet-Straton. Different approaches for using a doubled rope had already been described in the late 1700s and by Edward Whymper around 1860, though neither case were used with what would be considered abseiling. Charlet-Straton then used another doubled rope technique which was called the rappel during a failed solo attempt of Petit Dru in 1876. The technique he used to descend the rope would not normally be considered abseiling, and had already been described numerous times long before he used it, with most authors saying it risked injuries. 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-Straton again used the technique, with his companions assisting.
Abseiling is used in a number of applications, including:
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.
Abseiling is prohibited or discouraged in some areas, as it may cause environmental damage, conflict with climbers heading upwards, and/or endanger people on the ground.