příjde mi to jednoduší a sežere to míň matroše než "ty expresky v článku"

http://www.spadout.com/w/belay-device/

viz Carabiner Brake
The carabiner brake is an emergency rappelling method, in case you lost or dropped your belay device. It works similar to a rappel rack by using carabiners as brake bars. You need a minimum of three regular carabiners to set up the carabiner brake and a locking carabiner to connect the carabiner brake to your harness.