One thing that needs to be considered when top roping is the amount of stretch in the rope, relative to the height of the climb. From a 12m high wall, a fall from 3 - 4 m from the deck can cause you to hit the deck, sufficient height to cause significant injuries.
Edit: Assuming the belayer is at the base of the climb, hence 24m of rope. 3 -4 m fall is achieved not just because of the stretch but also because few climbers like the belay rope being tight enough to feel as if it's attached. |