Munter hitch + prusik for rope solo lead climbing

Question

Disclaimer

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)

Introduction

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

visualization:

caveats: (few possible issues i can think of)

• Might the prusik be loaded too much when falling?
• Might the prusik be tightened during ascent?

Answer 1

Your first concern is OK: tightened prussik loops do not cut ropes even after hard falls [1]. There are, however, several other problems with your set up.

• The munter hitch is not dynamic enough to allow the rope to run - even without the prussik loop.
• The prussik loop will definitely get tightened during ascent.
• The loop of rope that will form between the prussik and the munter will get caught in everything in its way, including the prussik loop itself.
• It is impossible to set the loop far away from the munter hitch enough so that everything doesn't get tangled.

There are more points that wouldn't work. Having quite some experience rope soloing, I can promise you something: anything that could go wrong will go wrong. You will be caught short of live rope when reaching anchors due to backup knots; you will misjudge the necessary amount of rope to let loose before your next protection; your live rope loops will get caught between your legs, and around holds, and around bolts; you will misplace backup prussiks to unweight the rope poorly and will have a great time wondering if you'll die in case of a fall... etc. The list goes on.

Rope soloing is much safer than free soloing, but it is the most technically complex type of climbing there is - especially if we're talking about big walls. If should be left to very experienced climbers only, and it takes a long time to learn. I advise you to try your set up at home (literally): anchor yourself to a chair or something and see if the rope runs through the munter hitch. I guarantee you it won't.

[1]. I would like to post a reference about the subject here, but this is rather unofficial info from many aid climbers I know and some sources inside brands conducting non-standard testing. You don't need to believe me.

Answer 2

I've tried many different methods of rope soloing, mostly because I was trying to find the best method. I've owned a soloist for years, and solo'd with grigris, as well as experimented with a few other terrifying techniques. I can tell you from experience they are all terrible. Rope soloing is cumbersome, tedious, and to second @QuantunBrick's notion, if it can go wrong, it will go wrong. It's a struggle all the way to the top. The only time I really have fun rope soloing is on toprope with a grigri.

The biggest flaw I see in your setup is using a munter hitch. The braking action on a munter is when the free end is parallel to the anchored end. This is the position your munter is going to be in the whole time you're climbing. Even with the soloist you start feeling a tonne of drag after you clip the second draw or place your second piece of pro. with a munter you're going to be fighting the friction in the knot constantly. On top of that your rope is going to get twisted like crazy, and adding a prusik into the mix means you simply are not going to get very far up the pitch before you're fighting with everything. No matter how you flake out your rope it's going to end up a nasty knot before you finish one pitch.

I'm not saying you shouldn't try your idea out. I've had all sorts of "great" ideas that proved really fast they were garbage after trying to implement them the first time. If you want to try it out, the best thing to do is go to a climbing wall and play with it while on top rope, that's what I did the first time I climbed with my soloist. Just solo your way up the wall with a belayer there to catch you in case your system doesn't. Then you can take a few intentional falls to test everything out.

Answer 3

I do see a need for a munter hitch. I make an anchor at the bottom like usual. I usually make also an anchor prusik at first bolt, because I think knots as the weakest point of the system, or place it otherwise you will keep rope longer if not fall on knots.

Then I tight a prusik on my harness, and climb giving slack through moving the prusik with one hand.

Prusik needs pretension to operate. It looks quite easy knot, it will pull on any direction you fall. I recently added a bull hitch to the side of the maillon to avoid cross loading. Prusik is also quite easy to slip, if not pretighten enough, or because it was cloudy, it had full moon, I did not feed my pet before go climbing etc. So have some patience using it.

I do also backup knots, which will probably hold, but it is hard to calculate how many meters will the fall be.

Munter is useful for rapelling. If there are hard moves on lead solo rope climbing and I want to try them, I protect the system with knots, or do them aid climbing, and repeat them solo top rope. Solo rope climbing is not sport climbing but it is ok for training, I rely more on common sense and instict.