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Ascend a Rope With an Auto-blocking Device   

by Kurt Hicks
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Overview 

The shadows are growing long across the desert as you rappel off the neo-classic Birdland (5.7+) in Red Rock, Nevada, after a successful ascent. In your haste to beat darkness (and avoid the resulting expensive ticket at the park gate), you forgot to grab the rack off the ledge before you started the rappel. Midway down the rappel, you realize your blunder. What to do? Time to go back up—and fast!


Basics 

To make this process work, you need to know three basic but crucial skills, and be carrying a tube-style auto-blocking belay device such as the Petzl Reverso or the Black Diamond ATCGuide. These include extending the rappel setup, the auto-block hitch, and the Klemheist knot. The extended setup not only gives you the option for ascending, but it’s also easier to manage than rappelling directly from your belay loop, especially when doing multiple rappels. An extended rappel also gives you the correct angle for the auto-blocking device to engage and lock off; rapping off your belay loop doesn’t give the correct angle for the device to auto-block correctly. To learn the two friction hitches, see below.


Auto-block 

Fig 1. Friction hitch <br />by Chris Philpot
Fig 1. Friction hitch
by Chris Philpot
(fig. 1) This is a friction hitch (not to be confused with the auto- blocking type of belay device) that is mostly used for backing up the brake hand while rappelling; you set it up before you begin to rappel. Also called a “third hand,” this rappel backup will stop your downward movement when engaged, so you can use both hands to untangle the rope or take care of other needs. In this extended-rappel setup with your brake hand in front of you, the auto-block should be clipped to your belay loop (other rappel setups will call for clipping it to your leg loop or similar) to make sliding it down the rope easier. Use a narrow, single-length sling or a short, closed loop of cord of similar length.

Wrap the cord or sling from top to bottom at least three times around the rope (both strands if you’re rappelling on two cords) until you have two to three inches of loop left. (If you have to wrap more than five times, your sling or cord might be too long.) Make sure the coils stack up neatly against each other (A).

Gather the loop from the top and the bottom and clip them onto a locking biner (B). Clip that biner to your belay loop and lock it. Your auto-block is successfully set up.


Klemheist 

Klemheist <br />by Chris Philpot
Klemheist
by Chris Philpot
(fig. 2) This friction hitch is easy to move after being weighted, and you can make it with any length of sling. In this case, it will be used to rig a foot sling for ascending the rope. For this application, we will use a flat double-length sling, but a cord is a fine way to make a foot prusik.

Wrap the sling around the rope at least four times, from top to bottom, leaving a few inches at the top. Make sure the wraps are neat and lay flat against the rope strands (C).

Run the excess sling on the bottom up through the top loop. When you weight the hanging end, the hitch will tighten down on itself and grab the rope (D).


The Setup 

Fig 3. Ascend the rope <br />by Chris Philpot
Fig 3. Ascend the rope
by Chris Philpot
(fig. 3)Here’s what to do if you decide you need to go back up the rope mid-rappel.

Begin by letting your auto-block hitch grab, freeing your hands. Tie one overhand backup knot with both strands of the rope below your device (A), then clip the knot to your belay loop with a locker. That way if the system were to fail—although failure is highly unlikely—you’re attached to the rope with a locker to the strongest part of your harness. Now, attach a double-length sling to the rope above the device using a Klemheist hitch—you should have two to three feet (B). Then clip a locking carabiner into the “ear hole” of the auto-block tube-style belay device you’re rapping with (C). And now the crux—grab the rope above the Klemheist and stand in the sling to unweight the belay device, and then clip the locking carabiner in the ear hole onto your belay loop (D). Sit back on the device that is now in “auto-blocking” or “guide” mode.

Go Up! Slide the foot sling as high as you can, and then stand it in—use the rope above you to pull up with your arms and stabilize your body. (Wrapping an arm around the rope above, so it sits in the crook of your elbow, helps maintain balance.) Pull the slack upward through the device, then sit back and let the device lock. Move the foot sling up and repeat.


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