Transformers! Your ATC belay device is also an ascender


Note - This post discusses techniques and methods used in vertical rope work. If you do them wrong, you could die. Always practice vertical rope techniques under the supervision of an experienced climber, and ideally in a progression: from flat ground, to staircase, to vertical close to the ground before you ever try them in a real climbing situation.

BLack DIAMOND ATC Guide belay device

BLack DIAMOND ATC Guide belay device

Auto locking plaquette-style belay devices (such as the Black Diamond ATC Guide, and Petzl Reverso) have become pretty much standard gear, for good reason. The auto locking feature when belaying your second directly off the anchor has another nifty capability that many folks are not aware of: rope ascender.

Now, you don’t want to use this when you head up a big wall climb, because it does add extra friction and it’s not quite as secure as a dedicated ascending system. But, for improvised rope climbing, such as in a rescue scenario, or if you find you need to ascend a rappel rope for some reason, this is a pretty cool trick.

Doing this is WAY better than the old school method of ascending a rope with two prusik loops!

Note - The effectiveness of this system, and the ease that you can ascend, greatly depends on the type of belay device you are using, and the rope diameter, how old/stiff the rope sheath is, and some other variables. Generally, if you have a newer smaller diameter rope with a smoother sheath, this is going to be easier. Practice, practice, practice in a controlled environment before you ever tried this in the real world.

Note - This tip only covers the basic setup for turning your ATC into an ascender. To actually climb the rope requires one more step, which we cover in another tip here.

There are two possible scenarios where you can set this up.

  1. one starting from a ledge or flat ground or otherwise good stance

  2. when you’re on rappel

Let's look at each one.

Method 1 - Rigging to ascend from a ledge or flat ground

Let’s start with the easiest set up, and assume you are on the ground or a ledge and have a rope you need to climb. This rope can be a single strand or a double strand. (Hopefully this is obvious, but this rope needs to be fixed in some way at the top anchor, either directly tied, or looped through an anchor point like a standard rappel. )

You simply rig your belay device just like you would to belay up your follower directly off the anchor, and clip the “anchor” carabiner to your belay loop. One locking carabiner in the ear, which you would clip to the anchor master point (here, the black one), and one locking carabiner blocking the rope the rope (here, the yellow one).

(Note: this system works a bit better if the rope blocking carabiner is round metal stock, rather than some fancy weight shaving I-beam type construction. The rope slides more easily and there’s a bit less friction on the rounded metal. If you have one, use it, if you don’t, no biggie.)


Standard set up, just like you would for a direct belay from the anchor (black carabiner would clip to masterpoint, yellow carabiner blocks the rope, the strand to the “climber” is always on the top.)

ATC as ascender 1.jpg

Now, instead of clipping the black carabiner on the anchor, you simply clip it onto your belay loop. Now, if you sit back in your harness, the rope should lock off. Slick!

ATC as ascender 2 arrow.jpg

Method 2 - Rigging to ascend while on rappel

Hopefully this will never happen to you, but there may be a time when you are rappelling, and for some reason need to go back up the rope. Maybe you missed the anchors, or maybe the rope got stuck above you, and you were careless and went below it without untangling the mess. Whatever, it doesn’t really matter, you were rapping down and now you need to climb up. Here’s how to do it.

There’s two different ways this can be rigged. It depends on whether you are rappelling from an extended rappel or from your belay loop . An extended rappel is easier and safer; lots more on extended rappels at this Tip.

Let’s look at each one.

First off, whenever you’re doing any shenanigans like this way off the deck, tie a “catastrophe knot” in the rope below you. This is an overhand on a bight in both strands, clipped to your belay loop. This is insurance; if you screw up any part of the next couple steps, you’re not going to fall to the ground. So do this first. If you were rapping with an auto block, going hands-free to do this is easy. If not, use the old-school Crafty Rope Trick (CRT) of wrapping the rope a few times around your leg to go hands free.


“Catastrophe knot” - Overhand on a bight in both strands, clipped back to your belay loop with a locker.

catastrophe knot.JPG

Note: Both these methods require you unweight your rappel device for a moment. Hopefully you can find some kind of a stance where you can temporarily unweight the rope. If you can’t do this, you’ll have to get creative. Add a short prusik plus a foot loop and standing in it, or use the Crafty Rope Trick (CRT) of wrapping a few loops of rope around your foot and standing up, temporarily unweighting your rappel device.

Note: For clarity, the catastrophe knot backup is not shown in the following photos.


A - Rappelling from an extended rappel (easier and safer method)

An extended rappel makes this method safer, because you do not need to unclip your rappel carabiner as described below in method B. When you do this for the first time, you might actually amaze yourself, because it’s so fast and easy, it almost seems like a magic trick.

The set up shown below, with one single runner, is one of various ways to rig an extended rappel. The extended rappel is covered in depth here.


1 - Clip a locking carabiner into the “ear” on your rappel device.

rappel ascender 4.JPG

2 - Unweight your device using one of the methods mentioned just above, and clip the “ear” onto your belay loop. Note the gold carabiner and yellow rap extension sling stay attached the whole time.

rappel ascender 5.JPG

Sweetness, you’re ready to ascend!

Your extension gives you enough slack for the blocking carabiner to properly work. Nice! One more reason to use an extended rappel.

And, one more cool thing about this method is that if you want to transition back into rappel, all you do is reverse the process. Simply unclip the black carabiner from your belay loop and you are back into rappelling position.

B - Rappelling from your belay loop


1 - Clip a locking carabiner to the “ear” of your rappel device.

rappel ascender 1.JPG

2 - Unweight your device using one of the methods mentioned just above, and clip the “ear” onto your belay loop.

rappel ascender 2.JPG

3 - Carefully, and I mean VERY carefully, unclip your rappel carabiner from your belay loop, WITHOUT unclipping the rope. If you do you unclip the rope at this moment, you are completely unattached to your rappel device, so practice this on the ground and do it VERY carefully!

You DID tie that catastrophe knot, RIGHT?

This somewhat sketchy and awkward step is NOT required if you're using an extended rappel, as shown above. (Take the hint, use an extended rappel . . .)

When you're done, it should look like the photo below.

rappel ascender 3.JPG

You now have your rappel device in the ascending position.