These are mechanical friction brake devices used when belaying. They allow careful control of the belay rope. Their main purpose is to allow locking off of the rope with minimal effort. Many types of belay devices exist, and some of these may additionally be used as descenders, for controlled descent on a rope, that is, abseiling or rappeling.
There are passive camming devices and active camming devices. Passive camming devices rely on the brake hand and a carabiner to lock off the rope. Sticht plates and the Air Traffic Controller ATC are examples of passive camming devices.
Active camming devices have a built-in mechanism that locks off the rope without the help of any other pieces of equipment. A GriGri is an example. The offset cam in the GriGri locks off the rope automatically to catch a falling climber, much like a seatbelt in a car locks off to hold a passenger securely. The GriGri fails at around 9 kN of force.
However, a GriGri, with its technology, often makes belayers become less vigilant. The GriGri is not a hands-free belay device. One mistake with the GriGri is reverse threading it. Reverse threading means to thread the GriGri the wrong way around, rendering the camming action useless. However, in a fall, with a reverse threaded GriGri, bending the rope sharply under the GriGri provides more than enough friction to hold a falling climber.
An example of traditional belay is the Body Belay or the Hip Belay, where the rope is wrapped around the body to provide enough friction to catch a climber. This is often used in Alpine climbing, where the routes are easy, and the belay must be fast.
Ice climbers often use a boot belay, where the rope is wrapped around one boot, thus providing friction.
0 komentar:
Posting Komentar