Descender (caving Equipment)
Descenders (or rappel devices) enable a user to descend a rope. They take several forms, amongst which are the Bobbins (caving), bobbin, rappel rack, and Figure 8 (climbing), figure 8. While there are others, these are amongst the most commonly used examples. It is also possible to use many Belay device, belay devices to rappel, though these have other drawbacks. History The first rappel devices were likely simple wraps around some sort of retaining rod or connector. One early device was described by Gerolamo Cardano, and another by Galileo Galilei. These early ideas, along with others developed throughout the next several centuries, were not commercially successful. Starting in the mid 1860s, Bobbins (caving), bobbin style devices similar to the Petzl simple, Petzl Simple were used by German fire brigades. In the 1870s, the first devices that were similar to the rappel rack were developed, though they lacked many of the features that define a modern rack, which were added in the ...
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