Continuing my almost weekly Tuesday (not always Tuesday) Tech Tip series this week I’m sharing how to build the Auto-Locking Munter (ALM) hitch. In last weeks post I shared how to tie a Munter Hitch (MH) directly onto a carabiner, a skill useful for any climber. This skill is a little more specialized and its usefulness can certainly be debated. I’m of the camp that believes more tools and options can be a good thing, if one is cautious as to when and why to apply such a skill. Let’s watch the video and then take a look at some scenarios where this skill can be useful and also address some of its limitations.
Now let’s take a closer look at this skill and where it might be helpful (or make matters worse). The first thing I’ll get out of the way is my mispronunciation of the hitch. “Munter” is correctly pronounced “Moon-Ter”. I apologize for my error and hope you’ll forgive me.
Another point that might seem important to some and minutiae to others is the lack of emphasis I place on tying the hitch with the load strand along the spine of the carabiner, which would essentially make the overall carabiner/hitch system able to withstand a larger amount of force. This author, along with some others whose comments can be found at the various referenced links I’ll include below, believe that the carabiner/hitch system will be able to withstand any potential load without carabiner failure. In fact I would argue if the system saw the amount of force that would make this load strand orientation important it would likely exceed the holding strength of a MH anyways, so I have decided to leave this out (except for this lengthy explanation as to “why”). By all means, if you strive for perfection you can spend some time mastering getting the load strand along the spine.
We should mention that the MH, and therefore the ALM, work best with large pear shaped carabiners. My favorite two carabiners for this hitch are the Petzl William Screw Lock Carabiner and the Petzl Attache. I prefer screw gate lockers when building MH/ALM’s because various auto-locking carabiners’s can slightly slow down the process and I’ve always liked Petzl’s “red unlocked indicator”.
Next we should discuss the usefulness of the ALM, a skill some have claimed is more a “guiding” tool then something a recreational climber should employ. To that I argue if you’ve already been using the MH (because it’s a great tool) then I think it is not a far stretch to add this adaptation of a hitch you are already using to your tool belt… with some understanding of the problems it might create. Let’s start with the “good” first.
There are many situations where I’ll choose a MH over my plaquette belay device (Black Diamond Guide ATC, Petzl Reverso, GiGi, etc). Moving quickly in alpine terrain, converting a basic “biner” belay on low angle slab to a more secure option, iced up winter ropes; all can be good situations to use the MH. Generally speaking these are situations where I am not expecting a second to even take a fall. From here there are a few things that can occur that can make converting the MH into an ALM a handy skill to have.
Your new partner who said he could easily follow 5.x struggles hard at the crux and calls to you that he can’t get through the moves. You start regretting not using your plaquette so that you can quickly build a 3:1 raise and give him a little “help” through the crux moves. Luckily you know the ALM and have a 3:1 built in a few seconds giving him the tension he needs to get through the tougher moves and carry on with the climb. It should be noted you will lose some efficacy in the haul system as the ALM does create more friction then most plaquettes.
Perhaps the pitch is 5.5 slab running up to a 5.9 thin bulge crux right at the end… you go with a quick moving MH and right before your parter starts moving through the crux you slip the 2nd locker into place and have just created a more secure belay… or maybe you just wanted to get a great shot of her stemming up the final corner and the ALM offers a bit more piece of mind while you lean out over the belay ledge to get the angle right…
You can use an ALM directly off your belay loop as part of a rope ascension system. A flipped plaquette, Petzl GriGri, Petzl Micro Traxion Pulley, or actual ascender will make rope ascension MUCH easier but this is a potential solution if you find yourself without any other tools. If you practice this at all IRL you’ll probably quickly decide to always carry a more efficient means of “progress capture” for rope ascension.
The biggest issue with the ALM is the complications that arise if you find yourself in need of lowering your partner after they have loaded the ALM. The worst case scenario would look something like this… You’re climbing an overhanging route and decide to use the ALM while your partner follows the last pitch. He botches a sequence under the roof and ends up hanging on the rope 5 feet from the wall due to the nature of the climb. The ALM has done its job and is easily holding the climber, but now what? There is a great ledge just 20 feet below the climber and if you had been using a classic MH you would simply lower him back to the ledge (or ground) to try the climb again. You could haul, but a 3:1 even with better efficiency than an ALM would be near impossible to hoist a 180 pound climber who is free hanging… a 5:1 might work but lowering seems so much quicker and less complicated. In this situation a quick block and tackle may take enough stress off the load strand to allow you to remove the 2nd carabiner that makes the MH an ALM allowing you to lower them back to the ledge. Even without a simple load transfer a small locking carabiner without a notched gate can likely be removed from a loaded ALM with some aggressive wiggling but an understanding of load-transfers (or the fore-sight to perhaps use a different option in overhanging terrain) would be prudent. A tested friction-hitch back up would be a wise addition here before removing the 2nd carabiner.
Like most climbing skills the Auto-Locking Munter is an option and not a solution for every situation. I find it useful a few times a season and think it’s a good tool to add to your kit. You should practice it quite a few times in non-life threatening situations before using it 600 feet up your next route.
Comment below! Was this Tech Tip new to you? Old news? Want to see more? Thanks for reading!
See you in the mountains,
Northeast Alpine Start