Questions about two-rope rappelling technique
I stumbled onto this site last January, and the trip reports look so fun, I decided I had to try this. I am going on my first real canyoneering trip at the end of the summer. There are four of us going, and two of us have a decent amount of experience climbing, so I am comfortable with most of the equipment and knots I’ll need to do the canyons we are planning (Zion – Subway, Mystery, Behunin). I think I’m comfortable judging the quality/dependability of the anchors for the rappels since I’ve done similar assessments on many of the climbs I’ve done that were bolted or I had to place my own protection.
99% of the climbing I have done has been small (100 ft or less) single pitch climbs where I only needed one rope or bouldering (no rope). So I have a couple questions about how you do the rapps.
I think I understand the basics of a two rope rappel - tie two ropes together, put it through a rappel ring, and feed both ropes through your rappel device. I read Tom’s Utah Canyoneering guide and Bill’s Canyoneering Primer over on Climb-Utah.com. But I have seen a lot of pics here where two strands of rope are on the face of the rock, but the person is only using one for his/her rappel. The second rope looks slack, so it’s not anchored to the bottom in any way.
For example, there are several good ones on sarahlizzy’s recent trip report. (Very cool pics by the way!)
In these photos, you can see exactly what I’m talking about. The unused half of the rope is obviously slack, so I don’t think it’s anchored to anything.
http://www.sarahlizzy.com/Zion2010/Mystery/Photo-9.jpg
http://www.sarahlizzy.com/Zion2010/Mystery/Photo-11.jpg
So here are my questions:
How is the rope attached/anchored at the top so the slack end of the rope doesn’t pull through the rappel ring?
And how would you retrieve your rope once you reached the bottom with that set up?
Do the first few people rappel using one strand, and then the last person use the double rope rappel?
Thanks for your help/patience!