Pit cave

A pit cave, shaft cave or vertical cave—or often simply called a pit (in the US) or pot (in the UK)—is a type of natural cave which contains one or more significant vertical shafts rather than being predominantly a conventional horizontal cave passage. Pit caves typically form in limestone as a result of long-term erosion by water. They can be open to the surface or found deep within horizontal caves. Among cavers, a pit is generally defined as a vertical drop of any depth that cannot be negotiated safely without the use of ropes or ladders.

Exploration into pit caves ("vertical caving", also called "pit caving") requires the use of equipment such as nylon kernmantle rope or cable ladders. More specialized caving techniques such as the single rope technique (SRT) are common practice and the preferred method of pit exploration for cavers worldwide. The SRT involves the use of 9–11 mm nylon static rope and mechanical descenders/ascenders.

Vertical caving is a specialized sport that should be undertaken only after acquiring knowledge of, and expertise in, proper vertical caving equipment and its use. For obvious reasons, vertical caving is more dangerous than "horizontal caving". Vertical caving requires the intimate understanding of ropes, knots, anchors, rappelling devices and ascending systems. Veteran cavers typically are knowledgeable in self rescue techniques including change-overs (the act of switching from rappel to climb while on rope) and pick-offs (the act of rescuing a stranded caver from his rope and returning him to the ground).

Pit caving was pioneered by the British geologist John Beaumont (c. 1650–1731) who gave an account of his descent into Lamb Leer Cavern to the Royal Society in 1681. French caver Édouard-Alfred Martel (1859–1938) first achieved the descent and exploration of the Gouffre de Padirac, France, as early as 1889 and the first complete descent of a 110 m (360 ft) wet vertical shaft at Gaping Gill, in Yorkshire, England, in 1895. He developed his own techniques using ropes and metallic ladders. In the 1930s, as caving became increasingly popular in France, several clubs in the Alps developed vertical cave exploration into a recognized outdoor sport.

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