The auto locking Munter hitch 


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.

Some information from this tip comes from Climbing magazine and Andy Kirkpatrick

Now, let’s be honest: this is sort of a trick knot that most folks will probably choose not to use. But, I know there are some knot geeks out there (like me!) who just want to try everything, so give this a whirl. 

Belaying a second directly off of the anchor is a modern and often preferred method for rock climbing, provided your anchors are bomber. 

An old school yet extremely effective way to do this is with a simple Munter hitch. The Munter has an advantage over an auto locking belay device such as a black diamond ATC or Petzl Reverso, in that you can easily lower your second if you need to. However, most people think that one of the downsides is that the Munter does not have the nifty auto lock feature that these belay devices offer.

Not so, grasshopper.  With this crafty rope trick (CRT) you simply add one carabiner to a Munter hitch to make it autolocking. 

The picture below pretty much explains things. By adding the carabiner, the hitch remains in raising mode, and cannot flip over the carabiner into lowering mode. 


Load strand is on the right, brake strand on the left.

image: mountain Project, josh beckner

image: mountain Project, josh beckner

A few things to note:

Let’s start off by saying this is kind of a guide trick, and may not have a lot of utility for recreational climbers.

This knot is best used in situations where the chance of a fall for the second is extremely unlikely. This is a subjective choice that depends entirely on the scale of the climbing team. Also, it should probably not be used on any sort of traverse, where the climbing is easy but if you slip you might swing into something vertical are overhanging. If there’s more than a slight chance that the second might take a fall or need to be lowered, you should use a regular Munter hitch or some other belay method. 

Let’s start with a few general principles of Munter hitch belay. 

  • As always when using a Munter hitch, it’s best to use a large pear-shaped “HMS” belay carabiner with round metal, which helps minimize friction. 

  • Using a thinner rope or a new one with a sheath that’s a bit slippery works best. I’ve tried it with my ancient 10 mm workhorse rope with a fuzzed up sheath, and it’s quite a bit of work to feed that rope through the hitch.

  • You want to use two hands. Your”feed” hand pulls in slack rope and the the brake hand simultaneously pulls it down. If you only pull on the brake side of the rope, you’re going to get a lot more friction, do more work than you need to, and potentially get some twists into the rope.  

Some specifics of using this hitch in auto lock mode:

  • You can add or remove this auto lock method into the Munter belay at any point in the pitch when your follower is coming up. For example, if the climbing starts off easy and then gets hard for the final part of the route, you could have your follower in auto lock mode for the easy part, and then simply remove the blocking carabiner when they get to the crux, so you have an option to lower them if necessary.

  • Be sure the hitch is set up in “raise” mode before you clip the blocking carabiner. 

  • You always want to test this before your follower begins, to be sure it is locking up properly.

  • One handy use for this knot is using it for light hauling, such as a backpack or light haul bag. The blocking function serves to capture the progress of your haul. Typically, another semi-obscure knot called the garda hitch would be used in this situation, but many people find this knot to be, shall we say, temperamental, 

This knot suffers from the same general problem as a standard auto lock delay device like the Petzl Reverso: if your follower is weighting the rope and needs to be lowered, you cannot do so. 

By far the easiest way to transition to lowering mode is to have your follower unweight the rope just enough for you to unclip the blocking carabiner from the load strand. Once the carabiner is gone, you are back to a normal Munter hitch, and can easily lower your follower. 

If that’s not possible, there is in fact a way to release a loaded knot. Use a small locking carabiner for the blocking carabiner.  Unclip the loaded rope from the blocking carabiner. This should allow the hitch to flip into lowering mode, and the small carabiner should pass through the large carabiner. As stated clearly in the first paragraph of this post, please go practice this in a controlled environment before you ever do it in real life.

There are quite a few good and short instructional YouTube videos on how to tie this. Here’s one from a competent source.