Rappel to Ascend

Ascend a rope with an auto-blocking device

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!


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. To learn how to extend (or "pre-rig") rappels, check out the Guide’s Tip in Climbing no. 305 or online at climbing.com/skill/pre-rigging-rappels. 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.


(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.


(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) 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.


Previous Comments

I think it's describing this essentially, though this is demonstrated on a single line and doesn't use the extension. http://climbinglife.com/instructional-videos-mainmenu-87/903-rope-rescue-systems-videos-advanced/450-using-an-atc-guide-to-ascend-a-rope-747 I wonder in the description above, after you do D (clipping it to your belay loop), if you shouldn't unclip your extension runner, but i guess it will just be hanging. I'm just thinking I don't want anything to interfere with that carabiner grabbing/blocking it as I'm ascending, just as you're not supposed to allow it to be blocked when using it in normal guide mode. so long as you have you backup guess it's fine.

Kal Phun - 01/27/2015 12:13:58

This is a neat shortcut for a simple rope-ascension setup, that could be useful for a very short climb. But this method will be far more tedious than using two prussik loops. That takes a bit longer to setup, but make climbing far more efficient.

Dan - 04/20/2014 9:37:13

First of all I'm not that into climbing in general, I'm just rope climbing to reach T5 geocaches. I've tried this setup because I felt that I needed an alternative to my usual GriGri2 + Ascension.setup. Eric's tip about using a longer sling with a knot in the middle is brilliant! I had some problem with a mid-end 10.8mm rope because of it's stiffness. Almost impossible to feed trough the ATC Guide. With a high-end 10.2mm rope it was flawless on both double and single rope.

Marcus - 04/13/2014 3:38:36

Chris Many people extend rappels with a sling, most of the time a 48" nylon. This allows the rappel device to stay out of the way of any back up, third-hand, that may be used (prussik) while rapping many times over again. The 48" girth hitched through the tie in points not the belay loop, and with a knot in the middle also gives the rappeler a tie in point at each anchor, similar to a PAS. It also makes it much easier to pre rig and check your partners rappels. Definitely the way to go for rappel multi pitch routes, in a sport or single pitch setting not as imoportant

Eric - 09/02/2013 10:58:30

Hmm... so the in the ilustration the climber was rapping with his device attached to his harness with a full length sling, instead of just on a locker clipped to the belay loop? (It also looks like there is a second sling from the device girth-hitched onto the leg loop attachment point... perhaps this illustration is taken from another skill page and applied to this one as well??) Does anyone have experience with this (separating your rap device with a sling from the harness, not the ascending a rope)? I've never seen this done, seems odd to me...

Chris - 08/27/2013 1:04:48

I'm confused about part D...what does the system look like after you attach the ear hole carabiner to the belay loop?

Dulfersitz - 07/02/2013 1:35:37