The figure 8

belay device A belay device is a mechanical piece of climbing equipment used to control a rope during belaying. It is designed to improve belay safety for the climber by allowing the belayer to manage their duties with minimal physical effort. With the right ...

is a piece of metal (usually an

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It h ...

alloy) in the shape of an 8 with one large end and one small end.

Usage

This device utilizes a large surface area in contact with a climbing rope to provide sufficient friction along with proper technique to be used as a

or for

rappelling Abseiling ( ; ), also known as rappelling ( ; ), is the controlled descent of a steep slope, such as a rock face, by moving down a rope. When abseiling the person descending controls their own movement down the rope, in contrast to low ...

. A figure 8 (sometimes just referred to as an 8) is used in conjunction with a

climbing harness A climbing harness is a device which allows a climber access to the safety of a rope. It is used in rock and ice climbing, abseiling, and lowering; this is in contrast to other activities requiring ropes for access or safety such as industrial ...

and locking

carabiner A carabiner or karabiner () is a specialized type of shackle, a metal loop with a spring-loaded gate used to quickly and reversibly connect components, most notably in safety-critical systems. The word is a shortened form of ''Karabinerhaken' ...

to control a belayed climber's descent, or one's own descent when rappelling.

Pros

Figure-eights offer a smooth controlled descent when rappelling and lowering climbers. They can be used with nearly any diameter

climbing rope A dynamic rope is a specially constructed, somewhat elastic rope used primarily in rock climbing, ice climbing, and mountaineering. This elasticity, or stretch, is the property that makes the rope dynamic—in contrast to a static rope that ...

and don't get as hot as other friction devices because of their ability to dissipate heat efficiently. The figure eight can also be used with a doubled rope, which is also possible with a rack but not a bobbin.

Cons

The figure-eight cannot be removed from the rope without detaching the device from the harness, and so could be accidentally dropped, particularly when tackling a rebelay. They also twist the rope which is a particular problem where a rebelay prevents the rope untwisting. They do not provide a convenient means to temporarily lock the descent at a rebelay.

References

Bibliography

*Cox, Steven M. and Kris Fulsaas, ed., ed. (2003–09). ''Mountaineering: The Freedom of the Hills'' (7 ed.). Seattle: The Mountaineers. .

External links

{{commonscat, Figure eight
Video Clip on Using a Figure 8 Belay DeviceMountainproject.com
Climbing equipment