This is a question regarding a theoretical technique, and not a tutorial, advice or recommendation. This technique has not been tested, and might potentially be completely unsafe. Climbing is dangerous, and doing it without a partner might be even more dangerous. In short: Don't try this at home (nor at the rocks)
There are people who rope-solo-lead-climb using various techniques and devices. Modified 'Grigris', 'Silent Partners', 'Soloists', knots or no knots, etc.
I started looking into this topic, considering the different techniques, and possible alternatives. I came up with a technique that would need very little gear, and wanted to hear people's opinions about it. Especially i want to hear if there are obvious flaws with the technique that i might be unaware of.
A short description of the idea (a little visualization follows):
- One end of the rope gets fixed to a suitable anchor at the bottom of the route
- The rope is 'connected' to the climber via a munter hitch through a carabiner.
- The rest of the rope is either placed loosely on the bottom, or carried in the climber's bag.
- A prusik between the climbers harness and the free side of the rope is attached to stop the rope in the case of a fall.
- When the climber climbs up, the fixed side of the rope is put under tension, which pulls rope from the free side through the munter hitch, hopefully without tightening the prusik.
- The climbing itself is pretty much the usual lead-ascent. Quick draws are attached to the side of the rope that is fixed to the bottom (of course).
- some backup-knots in the loose, excess rope might be added
caveats: (few possible issues i can think of)
- Might the prusik be loaded too much when falling?
- Might the prusik be tightened during ascent?