Vertical caving terminology and methods > Personal SRT gear
A very simple descender with no safety features. Within Britain (and in fact most of Europe), this is only used for education, never in caves. However, it is used within caves in parts of the USA, particularly regions where indestructible rope technique is used. Can also be used as a belay device. Twists the rope badly. Normally has to be completely disconnected from the D-ring in order to connect it to the rope, so there is a very real risk of accidentally dropping it down a pitch, particularly when hands are cold or tired. Keeper cords cannot be used to avoid this, because they prevent the rope from being wrapped around the descender. It is possible, but clumsy, to connect it to the rope without removing it from the D-ring, by swapping the positions of the rope and figure of 8 descender within the carabiner that connects the descender to the D-ring, while clipping the rope in and out of the carabiner. If this goes wrong, then the descender can be dropped by mistake, or can become jammed on the carabiner's gate. So this does not really solve the issue of accidentally dropping it.
There are several different ways the rope can be threaded through the figure of 8 descender, producing different levels of friction, or to make it automatically lock and prevent descent until it is pulled in a specific way. Some figure of 8 descenders may have extra little arms or holes, to provide further friction levels. However, the most common method is to take a bight of the rope through the larger hole, pull the bight over the small hole so it rests on the bar between the holes, then clip the smaller hole into a carabiner. Some users are adamant that the bight should be fed into the front of the larger hole, while others are determined that it should be fed through the back of the larger hole, but the reality is that since the descender sits vertically during use, it makes very little difference with a standard figure of 8 descender, and it is a matter of taste. Some of the other arrangements, particularly ones where the carabiner is clipped to the bigger hole, are downright dangerous when performing manoevers which could cause the load to be briefly removed from the rope, such as Y-hangs and rebelays, as the rope could simply fall off the figure of 8. Be warned that many tutorials on this subject conveniently assume that the rope will always be loaded, and that Alpine rigging does not exist.
By 1904, a fire brigade descender that operated on the same principle as a figure of 8 descender had been developed in Leipzig and Stuttgart, German Empire (now Germany), with an additional hole to get a little more friction. The actual figure of 8 descender was first invented in 1943, by Austrian doctor Max Pfrimmer. It was intended to be used for lowering objects on a rope, and it was not until the late 1950s that it was used as a descender by its inventor. It was first sold commercially as a descender in the early 1960s in München, Germany, then by 1963 in Britain, and 1965 in the USA. It was the first descender in common use in British caving, and was used during the 1971 and 1972 British expeditions to Ghar Parau. It only became popular in the USA after 1974.
This history section only covers the figure of 8 descender. This article also has a detailed history of many of the other devices and techniques that are used for vertical caving.
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