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.
OK, let’s get a couple things out of the way. Rope soloing can be dangerous. It’s an advanced maneuver that’s beyond the scope of what’s usually recommended at Alpine Savvy. I’ve done it a few times, and even on easy ground it was still spooky. I don’t recommend rope soloing unless you have to. If you do it wrong you could die or get seriously hurt. (And yes, that caveat also applies to lots of other things we do in climbing.) Consider yourself warned.
You need a bomber anchor that can take a solid downward AND an upward pull. That's all I'm gonna tell you. If you need more information than that, search Google-land for < rope soloing >.
Having said that… There may be some times in your climbing career when the clove hitch rope solo could be handy. For short fixing on a big wall (which is also an advanced method beyond the scope of this website), this is standard procedure. Some crazy rescue scenario, where you need to rope solo to save the day (without compounding your troubles further, of course . . . )
So, while this Crafty Rope Trick (CRT) is unlikely to be ever used by the majority of climbers, it’s so slick and better than just tying a normal clove to your harness, I had to mention it.
I first saw this printed in a British climbing magazine, probably about 20 years ago, which sadly I don’t remember. If anybody recognizes it please tell me and I will credit the source.
It could hardly be simpler. You only need a belay device, your belay carabiner and a second locking carabiner.
1- Tie a clove hitch, put both loops through the belay device, and clip the loops and your belay device to your belay loop.
2 - Clip a locking carabiner to the “top’ of the clove hitch.
To feed out slack, pull on the top locking carabiner.
Why is this awesome? No more fighting with the clove hitch to feed out rope! When you need some slack to climb, just pull on the locking carabiner to smoothly feed out a few meters. if you fall, the carabiner will cinch down on your belay device and stop you.
Additional cautionary note: If the yellow carabiner were to catch on to something at the same moment that you take a fall, the knot will fail.
But, a clove hitch failure should not mean a horrendous fall. In addition to the clove, you’re tied into the end of the rope, and you also should have back up in knots tied every 5 meters or so, typically an overhand on a bight clipped to your belay loop.
Of course, try this on flat ground, then in a very controlled vertical environment close to the ground before EVER trying it on a real climb.
I had a reader makes a comment along the lines of “this looks complicated, why not just use the ATC guide in auto block mode and solo on that?“ A very good question. The answer is, if you take a lead fall onto an ATC in guide mode, it MIGHT result in some of the following: the rope becoming hopelessly jammed in the device, the blocking carabiner twisting and doing weird things, and the ropes becoming inverted and thus losing almost all braking power. In other words, don't do this.
Besides, Black Diamond does not recommend using their ATC Guide for leading.