Single-rope technique

During World War II, a team composed of Pierre Chevalier, Fernand Petzl, Charles Petit-Didier and others explored the Dent de Crolles cave system near Grenoble, France, which became the deepest explored cave in the world (-658m) at that time.

In 1958, two Swiss alpinists, Juesi and Marti teamed together, creating the first commercially available rope ascender known as the Jumar.

The rappel rack was developed in the late 1960s by cavers in the Huntsville, Alabama caving club to facilitate long descents.

The evolution of mechanical ascension systems helped extend the practice and safety of pit exploration.

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 single-rope technique because they are slow in use, and ice or mud greatly reduce their efficiency.

Popular systems are: Modern single-rope technique uses specialized devices for both descent and ascent, and low-stretch kernmantel rope of 8-11 mm diameter.

For safe single-rope technique, 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.

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 re-belays used to avoid hazards such as loose rocks, waterfalls, and rope damage from rub points.

Racks are preferred as they have a much larger heat sink capacity and offer a much smoother descent on such pitches.