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.
A note on terminology before we start. There are a few different maneuvers out there that are known as a “munter pop”. What’s shown below is known by some as a “Munter Overhand Feed Through”, or MOFT. But, I first learned it as a munter pop, so that's what I'm going with here. If you search on the web for munter pop, you might find something that lets you disengage a munter hitch from a fully loaded rappel rope, hopefully without snapping off your fingers in the process. Both of these procedures use a munter hitch, and they both make a rather exciting POP on the rope when they activate, so I think the name applies to both. Please don't get bogged down in the terminology, and just take this rope trick for what it is.
What the heck is a “Munter pop”, you might be wondering? Is this some kind of delicious frozen Austrian ice cream on a stick? Not quite. It’s a very Crafty Rope Trick (CRT) that allows you to pass an overhand knot that’s connecting two climbing ropes directly through a munter hitch, either by lowering or rappelling.
There may be a few (hopefully rare) times in your climbing career when you want to lower your partner two full rope lengths to get them to the ground ASAP, or tie two ropes together as a single strand and have you both rap off.
Maybe it’s an incoming lightning storm. Maybe your partner got hurt, and you’re more than one rope length up, and you need to lower them to the ground. Maybe you’re on a multi pitch route with a relative novice, and you want to get back to the base of the route is efficiently as possible. It might be faster to lower your less experienced friend all the way to the ground on two ropes, and then you make two normal rappels to get down. That way there’s only two raps to do, rather than four. In any case, knowing how to lower someone two complete rope lengths might be something that could really save the day.
Yes, you could fix one end and rappel two rope lengths on a single strand, but then you’d have the fun of passing the knot. If you both know the clever technique of a munter pop, you can do this on rappel. If one of you does not, it's probably better to rappel past the knot like we show in this other tip, actually a very simple thing to do if the terrain is anything other than overhanging.
Note, this is a fairly advanced maneuver that you absolutely need to practice before you try in the real world. It’s definitely strange, at least it was for me the first few times I tried it, and I did not find it very intuitive. In fact I had to do it a few times in slow motion to really understand what was going on!
Practice both the lower and the rappel. The concept is pretty much the same, the execution is slightly different.
First off, for lowering practice, you need some tension on the rope to really do this right. The easiest way is to have a friend just lean back with body weight on the rope a few feet away (on a flat floor please, not on a cliff the first time you try this!)
Second, you’re going to be lowering and rappelling on a munter hitch. Be sure you know how to tie it, and how to lower on it. Use a friction hitch backup attached to the brake strand of the rope, and clip the hitch to your belay loop with a locking carabiner.
Third, this requires a large diameter HMS, pear-shaped locking belay carabiner. Sidenote, if you want to learn what “HMS” means, click here.
Good choices for a carabiner would be the Black Diamond Rocklock (photo below) or similar extra-wide carabiner. Do not try this unless you have a wide HMS carabiner, or else the knot could get stuck.
This works best on skinnier ropes. Anything under about 9.5mm should be fine.
Here’s how it works for lowering. (It’s pretty much the same for rappelling.)
Tie two ropes together with a flat overhand bend.
Tie your partner in one end of the rope.
Tie a munter hitch onto the large diameter carabiner on the anchor master point, and start lowering your partner. Back up your lower: put a friction hitch on the brake strand and clip it to your belay loop.
When the knot connecting the ropes arrives at the carabiner, continue lowering (or rappelling) slowly. Try to assist the tails of the rope through the carabiner, but do it carefully so your fingers don’t get caught. Yes, the overhand bend will pass through the carabiner! (Like I said, Crafty Rope Trick (CRT) for sure!)
If you did it right, once the knot passes through, you’re going to have what looks like a strange looking mess of three strands of rope coming down from the carabiner, looking something like this.
The “U” shaped loop of the munter is caught on the overhand bend. Yes, this looks like a spaghetti pile, but there’s an easy fix. When you’re practicing, this is the part you may want to do slowly to see what’s going on.
Take the two tails of the rope, pass them through the loop coming off the carabiner, and pull. Warn your partner before you do this, they’re going to drop a little! At this point, if the person being lowered can lean into the rock or slightly unweight the rope for a moment, they can make this procedure a bit easier. The more the knot has passed through the carabiner, the more they will drop, so as seen below, ideally don’t let that overhand knot go more than about 6 inches below the carabiner.
This is the “pop” part!
The munter hitch will magically POP back onto the carabiner, and you can continue lowering. Yes, it looks like an optical illusion, as in “what the hell did I just see!?” If you want, try it a few more times in slow motion to see what’s really happening.
Warning, if you have lowered more than about 1 foot of slack through the carabiner, and or have not warned your climber what’s about to happen, they’re probably going to poop their pants when they hear a popping noise and the rope suddenly drops a foot. This scenario will be a little less dramatic if you can have your second lean in on some kind of a stance to momentarily take their weight even partially off the rope.
Check out the video below where a professional guide Karsten Delap shows you how to do it. (And for the curious mind, “MOFT” means “Munter Overhand Feed Through”)