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.

ee also

*Pit cave

References

* Cite book
author=Sparrow, Andy
authorlink=
coauthors=
title=The Complete Caving Manual
date=1996
publisher=
location=
isbn=978-1861260222
pages=
* Cite book
author=Smith, Bruce L. R.; Padgett, Allen; Speleological Society Vertical Section, National
authorlink=
coauthors=
title=On rope: North American vertical rope techniques for caving... rappellers
date=1996
publisher=Vertical Section, National Speleological Society
location=Huntsville, Ala.
isbn=1-879961-05-9
pages=
* Cite book
author=Marbach, George; Tourte, Bernard; Alspaugh, Melanie
authorlink=
coauthors=
title=Alpine Caving Techniques
date=
publisher=Speleo Projects,Switzerland
location=
isbn=3-908495-10-5
pages=
* Cite book
author=Lyon, Ben
authorlink=
coauthors=
title=Venturing underground: the new speleo's guide
date=1983
publisher=EP Pub.
location=East Ardsley, Wakefield, West Yorkshire
isbn=978-0-7158-0825-2
pages=
* Cite book
author=Elliot, Dave
authorlink=
coauthors=
title=Single rope technique: a training manual
date=1986
publisher=Troll Safety Equipment
location=Oldham
isbn=978-0-904405-68-2
pages=

External links

* [http://storrick.cnchost.com/VerticalDevicesPage/VerticalHome.shtml Museum of vertical devices]