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.
Sure, you know your plaquette-style blade device (such as a Black Diamond ATC Guide or Petzl Reverso) works great when you’re belaying your second direct from an anchor and want the rope to autolock. But did you know you can also rig it in a similar way for top rope belaying?
With this set up correctly for toprope belaying, if your second takes a fall, the device will lock, just like with a Grigri.
(Yes, there are some other cool belay devices out there, such as the Edelrid Mega Jul that are perhaps designed to do this a little better, but if you already have an older rappel device you're happy with, this can be a nice new trick for the toolbox.)
Note: Unlike a Grigri there is no lever to unlock it, so they can make things a little more interesting if you have to lower with the rope under tension, but for standard top roping, this is pretty slick. Here’s how to set it up.
You need one spare locking carabiner, and a standard quickdraw set up with two locking carabiners. Ideally one of these lockers will be a round stock carabiner, to give a slightly smoother rope feed.
Clip the locking quick draw to your belay loop, with the rounded carabiner away from your body.
Feed the rope through your belay device in the normal manner, and clip it to this rounded carabiner.
Now, clip the spare locking carabiner through the “ear” of your belay device.
Then, clip that carabiner onto your belay loop. (Be sure all carabiners are locked.)
You’re now in “Grigri” auto locking belay mode. You can pull in slack rope as your climber moves up, but if your second falls, the device will lock.
Be SURE and test this to check the correct strand of the rope is locking up under load. If you set this up with the rope coming out of the wrong side of your ATC, it will allow you to feed rope out, but not take rope in. Absolutely check this before your second starts climbing.
To change back to lowering mode, simply unclip the “ear” carabiner from your belay loop and you can lower normally. Note that to do this, your climber needs to unweight the rope for a moment.
Also note, that this is basically the identical setup for using this style belay device as an ascender, which we cover in a separate tip.
Practice this on flat ground until you have it down!
Here is a short video from AMGA certified guide Dale Remsberg showing how to do it. As Dale mentions, this can be a good technique for ice or snow climbing, when you’re using skinny ropes, have on big gloves, have cold hands, or all of the above. (The video is on Facebook, so I cannot embed it here on my website.)