A single loop of webbing is the most straight-forward method to rig a rappel and is one of the most common.
To rig a single loop of webbing:
By tying the webbing in a loop, you get almost twice the capacity of a single strand of webbing, which means that your loop could hold up to 8,000 lbs.
In certain situations, the webbing loop could slip off the rock or slide up the tree.