Single Rope Technique

Single Rope Technique (SRT) is a set of methods used to descend and ascend ropes. SRT is used in caving, potholing, rock climbing, rope rescue, roped access for building maintenance and by arborists for tree climbing.

American caver Bill Cuddington, known as "Vertical Bill", developed the SRT in the late 1950s, thus earning him the additional moniker of "father of vertical caving". The name, however, was coined by Bruce Bedford as editor of Descent magazine.

.....Technique.....

Ascent

For ascent (prusiking or "jugging"), cammed devices (ascenders) are used that can be pushed up the rope but that lock and hold the user's weight when a downward force is applied; these must also be easily removable from the rope without being detached from the user. Knots such as the Prusik, Bachmann and Klemheist are used to ascend ropes in emergencies in climbing and mountaineering; they have ceased to be the primary ascent method in SRT because they are slow in use, and ice or mud greatly reduce their efficacy.

Numerous prusik systems have been devised. Popular systems are:

* Sit-stand systems (also known as frog rig) - One ascender is at chest level attached to the sit-harness, and a second is held in the hand with a long loop of rope for the feet. Movement up the rope is by repeated moving of the foot-loop ascender up the rope, pushing up with both feet together, and sitting, supported by the chest ascender. This motion appears like a frog kick.
* Rope-walking systems - One ascender attached directly to one foot, and the second connected to the other foot by a rope with the ascender higher up to avoid clashing. Movement up the rope is by alternate stepping movements with the feet.

In general, while rope-walking techniques may be very effective for climbing long unobstructed pitches, they prove less versatile in cases of awkward passages and complex rope rigging with rebelays used to avoid hazards such as loose rocks, waterfalls, and rope damage from rub points.

Sit-stand systems are almost universally favored in Europe due to the conditions and the tradition of rigging to avoid rub points which allows for lighter weight ropes.

Many cavers in the southeastern USA favor rope-walking systems due to the enormous pitches, and have traditionally used simple rope rigging, with the rope anchored only at the top of the pitch and touching the rocks all the way down. This is sometimes pejoratively called Indestructible Rope Technique.

Descent

Descent (abseiling or rappeling) uses various forms of friction brake to control speed. The most commonly used are the Petzl Stop (self-locking) and Bobbin, and rappel racks. For safe SRT, especially on drops with complex rigging with intermediate belays, it is essential that the abseiling device can be removed from the rope without being unclipped from the harness.

Equipment

Modern SRT uses specialised devices for both descent and ascent, and low-stretch kernmantel rope of 8 mm-11 mm diameter.

Other essential items of a personal SRT set are a sit harness and one or more safety cords ("cows-tails") terminated in carabiners, for temporary attachment to safety ropes at the heads of drops and used in manoeuvres at intermediate rope belays.

Abseiling

Abseiling (German: abseilen, "to rope down"), rappelling in American English, is the controlled descent down a rope in rock climbing, mountaineering, caving, and canyoneering; the technique is used when a cliff or slope is too steep and/or dangerous to descend without protection. Abseiling is used chiefly in British English, while other Anglophone countries use different terms.

Slang terms

Slang terms for the technique include: rapping or rap jumping (American slang), abbing (British slang for "abseiling"), jumping (Australian slang), roping down, roping, seiling (Australian slang), snapling (Israeli slang), rappling (Hindi slang).

History

The origin of the abseil is attributed[2] to Jean Estéril Charlet, a Chamonix guide who lived from 1840-1925. Charlet originally devised the technique of the abseil (or rappel) method of roping down during a failed solo attempt of Petit Dru in 1876. After many attempts, some of them solo, he managed to summit the Petit Dru in 1879 in the company of two other Chamonix guides, Prosper Payot and Frédéric Folliguet, whom he hired (a rather paradoxical move for a guide). During that ascent, Charlet perfected the abseil.

Equipment

* Helmets are worn to protect the head from bumps and falling rocks. A light source may be mounted on the helmet in order to keep the hands free in unlit areas.
* Gloves protect hands from the rope and from hits with the wall. They are mainly used by recreational abseilers, industrial access practitioners, adventure racers and military as opposed to climbers or mountaineers. In fact, they can increase the risk of accident by becoming caught in the descender in certain situations.
* Boots or other sturdy footwear with good grips.
* Knee-pads (and sometimes elbow-pads) are popular in some applications for the protection of joints during crawls or hits.
* Ropes used for descending are typically of Kernmantle rope construction, with a multi-strand core protected by an abrasion-resistant woven sheath. For most applications, low-stretch rope (typically ~2% stretch when under the load of a typical bodyweight) called static rope is used to reduce bouncing and to allow easier ascending of the rope.
* A harness is used around the waist to secure the descender. A comfortable harness is important for descents that may take many hours.
* A descender or rappel device is a friction device or friction hitch that allows for rope to be paid out in a controlled fashion, under load, with a minimal effort by the person controlling it. The speed at which the rappeller descends is controlled by applying greater or lesser force on the rope below the device or altering the angle at which the rope exits the device. Descenders can be task-designed or improvised from other equipment:
o Mechanical descenders include braking bars, the figure eight, the abseil rack, the "bobbin" (and its self-locking variant the "stop"), the gold tail, and the "sky genie" used by some window-washers and wildfire firefighters.
o Some improvised descenders include the Munter hitch, a carabiner wrap, the basic crossed-carabiner brake and the piton bar brake (sometimes called the carabiner and piton). There is an older, more uncomfortable, method of wrapping the rope around one's body for friction, as in the Dulfersitz or Geneva methods used by climbers in the 1960s.

Application

Abseiling is used in a number of applications, including:

* Rock climbers returning to the base of a climb or to a point where they then try a new route.
* Recreational abseilers, who return to the top of the line by track, stairs or other methods and abseil again.
* Recreational canyoners, who travel down mountainous watercourses where waterfalls or cliffs may need to be descended and simply jumping is too dangerous or impossible.
* Recreational caving, where underground pitches are accessed using this method (Single Rope Technique).
* Adventure racers, whose events often including abseiling and other rope work.
* Industrial/Commercial workers, who use abseiling techniques to access parts of structures or buildings so as to perform maintenance, cleaning or construction. (eg window cleaners, railway scalers, quarry workers, etc.)
* Access to wildfires or wilderness rescue/paramedic operations by rapelling from a hovering helicopter.
* Confined spaces access, such as investigating ballast tanks and other areas of ships.
* Rescue applications, such as accessing injured people or accident sites (vehicle or aircraft) and extracting the casualty using abseiling techniques.
* Steeplejacking, as a replacement for bosun's chair.
* Military and police applications, such as entering a building through a window or hard to reach spaces via aircraft. This is a technique used by special forces and SWAT teams.

Abseiling can be a dangerous sport, and presents risks, especially to unsupervised or inexperienced climbers. Abseiling is, in fact, viewed by climbers as being more dangerous than climbing itself, as the rope system is taking the weight of the practitioner constantly rather than only in the event of a fall. Moreover, a high percentage of mishaps classified as "climbing accidents" actually occur when abseiling.

Abseiling is prohibited or discouraged in some areas, due to the potential for rock erosion and/or conflict with climbers heading upwards.