This technique is most applicable with a larger group that needs a fixed line. With a small group, the first climber could just belay the second climber down to him after building the anchor.
The crux of this trick is played out in the video very quickly. Watch closely at the 1:50 second mark.
I'm not sure that I'm all that excited about the ratty sling and the quicklink shown in the video. Before committing to anything, it's really important to make sure that your anchor is completely solid.
In review, the steps are as follows:
- Belayer belays climber out to edge.
- Climber at edge builds an anchor and fixes the line.
- The climber at the top converts the line by running it through the quicklink and clipping a carabiner to a clove-hitch on the backside. This could also be done by running the rope around a tree or a boulder. If you do it through a tree or a boulder, be sure that there isn't too much friction and that the line could still be retrieved.
- Once the line is fixed on both ends, a climber could clip in with a sling to a carabiner to descend or the climber could put a friction hitch on the rope. A friction hitch would provide a higher level of security.
- Only one person should move on the fixed line at once.
- The last person will bring down the backside of the fixed line, the end that is not running through the quicklink.
- Once the rope is released from the anchor, it will be able to be easily pulled down.
