The necessary and sometimes black art of getting downStanding on top of a summit, after congratulatory hugs and handshakes, I make it a point to say out loud, ‘We’re half way there.’ I say this not necessarily for my partner’s benefit, but for my own. Statistically, more accidents occur while descending mountains than climbing up them. Fatigue, falling darkness, carelessness, and the inherently dangerous nature of rappelling all stack the deck against the climber.
To increase the odds of a safe and efficient descent, there are a few techniques and rules of thumb I observe and so should the climber with an interest in longevity:
Wands can be easily and cheaply made from three foot, green bamboo stakes accquired from your local home and garden center, and a roll of pink or orange surveyor's tape. Split the top of the stake enough to slip a piece of tape into. Tape the top of the split with duct tape. Some climbers like to use two pieces of surveyors tape, one bright, one dark to improve visibility in variable light conditions.
Get an alpine start. It is easier to start in the dark than to finish in the dark. Along the same lines, if you are not planning on a carry-over, set a turnaround time and stick to it. This will help you avoid descending in the dark. LED headlamps are small enough that it is inexcusable not to carry one.
Learn to down climb. Down climbing is often faster and safer than rappelling. Committing to climb down routes you top-rope will hone this valuable skill. Knowing when it is safer and quicker to down climb and when to rappel takes some judgment. When I climbed the Park Glacier Headwall on Mount Baker we encountered 150 meters of bullet hard, 50 degree glacier ice above a yawning bergschrund. We rappelled on V-threads. The previous party reported perfect step kicking neve’ which they down climbed. Had we relied on the two week old beta and not been prepared to rappel, it would have meant nervy belayed downclimbing.
Be ready to rappel. If climbing a technical route, carry 20 meters of tat to build anchors in addition to your prusik slings and cordellette. I prefer 7mm perlon. It is both acceptably light and strong. I also find it easier to thread through V-threads. Carry rappel rings, quick links, or ‘leaver’ carabiners to run the rappel ropes through. I rack my pitons, nuts, and hexes on old carabiners that I retrieved from bailing sport climbers. I mark these differently and use them first to make rappel anchors.
Know your anchors. Look for natural features; trees, horns, flakes, chock stones, and icicles can all make quick and secure anchors. Be creative and persistent. One difficult descent found my partner and I on a small ledge in the middle of a wet, overhanging cliff. There were no cracks for pro. I started digging the sod from behind a ripple in the rock to reveal a flake just barely large enough to accept a prusik sling for our last rappel anchor. It wasn't the best, but was a far better option than trying to down climb wet, overhanging rock in mountain boots.
To build a V-thread, drill two holes that intersect deep in the ice. Push the hook end of the retriever to the back of the longer hole and thread 7mm perlon to the back of the other hole. Snag the cord and pull it through. Tie both ends with a double or triple fisherman's knot. If I don’t love a V-thread, I make two and equalize them. If rappelling on a single thread, use an un-weighted back up anchor and make the fat guy go first. The lightest climber rappels last after pulling the back-up anchor.
Carry plenty of passive pro. Nuts, tricams, and hexes securely set behind a good constriction are more secure and cheaper than cams. The ringing sound of a piton hammered home is music to my ears. A rack of passive protection costs about the same as tank of gas. Leave two pieces, equalize them, and consider it the cost of doing business. Someone loves you and your life is worth more than nine dollars.
Rappelling steep snow is tough. Carry and know how to properly place pickets if climbing steep snow routes. Know how and when to build a safe bollard. Flukes are not as versatile as pickets, but in soft spring snow, nothing holds as well. Also, know how to improvise. Stuff sacks filled with snow, trekking poles, tent poles, and skis buried in T-slots as dead men can work if you are desperate.
Be smooth. To help prevent the ropes from hanging up, coil each strand in a butterfly coil and drop the middles first, followed by the ends. Ensure you are not dropping the rope on another party and shout 'rope' before tossing them. Television and the movies often depict rappellers making big, swooping jumps as they slide down the ropes. Don't do this. This practice imparts unnecessary forces and vectors on the anchor. Rappel as gently as possible. Try to avoid unweighting and re-weighting the ropes.
If rappelling on a single climbing rope and a thin tag line, be aware of the tag line is prone to turning into a major cluster f&#%. Coil the tag line into a stuff sack hanging from a harness loop and feed it as you rappel. Stiff 5.5 mm tech cord (Maxim makes an excellent one) is stronger than perlon and less likely to knot up. The tag line should be 5 meters longer than the lead line, because of the different elongation of the two cords. Place the knot on the tag line side of the rappel ring. You will be retrieving the ropes by pulling the tag line.
Be safe. Before casting off, double check to make sure your harness is buckled and the rappel device properly threaded. Test the set up by fully weighting the rappel ropes while still connected to the anchor with a chicken sling. Tie bulky knots in the ends of the rappel ropes or better yet tie both rope ends together. Tying the ends together will make it impossible to pull one end of the rappel ropes down without untying both ends. Attach a sling through your harness and clip a carabiner through it and one strand of the ropes. This will make it impossible to rappel off the ends which are tied together. Use an auto block or prusik cord in case you lose control.
To make an auto block, clip a carabiner to your brake hand side harness's leg loop. Clip a short loop of 6mm perlon to the carabiner and wrap it three to four times around both strands of the rappel rope and clip the other end of the loop to the same carabiner. As you rappel, your brake hand keeps the auto block from tightening around the ropes.
Everything you wanted to know about abseiling but didn't dare ask. A nice article from across the pond about rappelling.
http://www.summitpost.org/rappel-anchors-a-few-thoughts/846367 SP article on rappeling