Tech Tip: Auto Locking Munter (ALM)- do's and don'ts

Simple, light and fast. These are aspects of alpine climbing that we must constantly strive for if we are to be efficient and reduce our exposure to objective hazards in the mountains. And sometimes this means reducing the security of yourself and your partner. The ALM stands out as an exception. It provides a secure, light and simple belay system. It’s fast to load, it can be made to be as secure as a plaquette (Reverso, ATC Guide, etc) and you can go from a standard munter to the ALM mid pitch.

The auto-locking munter hitch can come in handy in a variety of situations. The munter is a belay technique that is often used by mountaineers and guides due to its ease of use and efficiency. Essentially, the ALM is just a munter hitch tied on to a locker and then a second locker (the blocker-locker) is clipped to the munter and the follower’s strand allowing the munter to ‘auto-lock.’ As simple as it is, there are a couple nuances that you should know before you use it in the field.

*The ALM will create more friction than a standard munter. The friction is best reduced by using the biggest pearabiners you have. Feeding the rope through the ALM, instead of pulling it through, will help reduce both friction and the tendency for twists to occur in the brake strand.
*Generally speaking, the ALM should only be used in top belay situations.
*It is extremely difficult or impossible to lower your follower once the ALM is loaded.
*It’s best to use a locker for the ‘blocker-locker’, especially if you are going to be going hands free while belaying. Also, try to clip the two strands so that the second’s strand doesn’t brush past the gate in a direction that might open it (see the example in the picture below).

The ALM with the gold ‘biner acting as the blocker-locker. The shorter strand of rope (with the yellow tag) represents the strand that goes to the follower. When the follower’s strand is loaded, the weight will try to rotate the munter into the back of the ‘biner and out the front. Because the munter is clipped to the loaded strand and acts as a post, it won’t let the rotation occur; this is what creates the locking effect.


As with any new technical skill, you should practice this technique with someone that can coach you on the proper application of the given skill. Be safe out there!

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A "belay" device that can't be released strikes me as a super bad idea for anything but really easy ground. I doubt many people will adopt this, but if it happens, there are going to be fiascos with climbers hanging two feet above a ledge and the belayer unable to lower them.

Maybe the rope runs a bit diagonally and the follower swings under a little ceiling---the party had better anticipate every possible bad situation before using an unlockable system which, once loaded, is not releasable and could be a major chore to unload: think about the self-rescue geekery needed to unweight something which is functionally equivalent to a loaded knot.

Anyone using this ought to be able to explain with great clarity exactly what otherwise unavoidable problem they are solving by using such a system.

If I place the second locker with the gate facing out it seems possible to get that locker out while the rope is under load.

Just testing at home without real loads so it's hard to say.

It's great to have a bag full of tricks for those unexpected situations. I'll add this one but I am finding it a bit difficult to imagine needing it.

If I really want an auto-block belay off the anchor, I'll use my ATC Guide or Mammut SMART (love that new toy...review coming soon). If I happened to drop whichever device, I'd use a Munter but I don't imagine there would be many instances when auto-block would be an absolute necessity and, given the inability to lower a climber, I don't know if the benefits would outweigh the limitations.

But, it is good to have as many tricks in the bag as you can.

thanks for re-iterating freedom of the hills basic info.

Why not just extend a prussic from the anchor point and attach it to the load line if you MUST have an autoblock with your Munter?

rgold wrote:A "belay" device that can't be released strikes me as a super bad idea for anything but really easy ground. I doubt many people will adopt this, but if it happens, there are going to be fiascos with climbers hanging two feet above a ledge and the belayer unable to lower them.

rgold, your point can't be highlighted enough! This technique should only be used on low angle terrain and it is not something that should replace your plaquette (atc guide, reverso, etc) on steeper routes. The ALM should never be used if you think the follower won't be able to get up the pitch.

Personally, I use the ALM quite often while guiding in the Tetons. I often belay clients with a munter because it allows be to put them on belay within a couple seconds and then if I want to let go of the rope to refuel I put another 'biner into the munter and I'm free.

Tim Zander- I'll have to check that out in the field. I'll let you know what I find. Seems logical though.....

Kevin D- A prussic would be way too slow and is liable to get caught up in the munter as you reel in rope. We're looking for speed here.

This was discussed years ago in Climbing magazine.

climbing.com/print/techtips…

It is true, many of us learned this seven or so years ago from the magazine article linked above. But that by itself doesn't mean it isn't worth mentioning; a lot of climbers do not know about it still.

And agreed, it should be fine for belaying on easy low-angle rock, although this may be primarily a guiding technique.

One application it is good for is improvised prussiking. A prussik on the rope for a foot loop and a locking munter at the harness make for an efficient improvised prussik set-up with minimal equipment requirements.

jakeP wrote: Maybe you have that seventh edition though.

Nope, not in the seventh edition. Maybe he has that new eight edition though.

rgold wrote:One application it is good for is improvised prussiking. A prussik on the rope for a foot loop and a locking munter at the harness make for an efficient improvised prussik set-up with minimal equipment requirements.

interesting

Here is a video I did on this a while back:

karstendelap.com/2012/05/09…

Since this has come up again, it is worth mentioning that Bearbreeder has described an approach to unlocking the locking Munter in the following thread: mountainproject.com/v/garda… .

Bearbreeder's quote:

you can release it under load

- use a larger biner for the actual munter
- use a smaller biner for the lock
- to release simply unclip the strand from the biner lock ... even under load you should be able to shimmy the rope out
- the small biner will now rotate through the large biner and the munter works normally

rgold wrote:Since this has come up again, it is worth mentioning that Bearbreeder has described an approach to unlocking the locking Munter in the following thread: mountainproject.com/v/garda… . Bearbreeder's quote: you can release it under load - use a larger biner for the actual munter - use a smaller biner for the lock - to release simply unclip the strand from the biner lock ... even under load you should be able to shimmy the rope out - the small biner will now rotate through the large biner and the munter works normally

as a warning ... this works best with half or thin ropes, same with the ALM in general .... with thick ropes its a gongshow ...

;)

Karsten Delap wrote:Here is a video I did on this a while back: karstendelap.com/2012/05/09…

I first learned this technique from Karsten's video last year. Thank you both for providing the community with a valuable bit of technical information. Josh, I'm sorry to see your effort was so negatively received... I used it today, in fact, out at Rumbling Bald to bring up my partner so I could go hands-free to take photographs

Thanks again for your advice and your efforts to enlighten the skeptics!

Simply put, this is a guiding technique and should be selected as a belay method at the utmost discretion.

Josh, the point that might be made about your setup illustrated above is that the munter is tied "backwards" based on your description of the shot end or yellow tagged end going to the second. It is preferred that the loaded strand of a munter whether flipped in the belay or lower orientation be closest to the spine of the carabiner. Karsten's video depicts the munter tied in this manor.

Grant Price wrote:Josh, the point that might be made about your setup illustrated above is that the munter is tied "backwards" based on your description of the sho{r}t end or yellow tagged end going to the second. It is preferred that the loaded strand of a munter, whether flipped in the belay or lower orientation, be closest to the spine of the carabiner.

I'd argue that it's more important to tie the Munter so the break strand does not unscrew the gate. I would also venture to say (and I'm sure I'm opening up a can of worms here) that it doesn't matter if the load strand is on the gate side or not- it's just simply not going to break the biner unless you're dealing with factor 2 falls, rescue scenarios with mega loads, etc. In which case, the ALM should not be incorporated into the system.

When using the Munter in guiding scenarios or any other scenario where you are belaying from above, you simply can't generate a load that will break a biner that is not loaded right on the spine. Think about all the lead fall catches that happen every day where the rope (or GriGri) is not loaded on the spine side, but on a random spot in the basket of the biner.

I'm not trying to be an antagonist, I just want folks to re-think what modern hardware is capable of and to make decisions based on the massive collection of data that is out there.

Josh Beckner wrote: I would also venture to say (and I'm sure I'm opening up a can of worms here) that it doesn't matter if the load strand is on the gate side or not- it's just simply not going to break the biner unless you're dealing with factor 2 falls, rescue scenarios with mega loads, etc. In which case, the ALM should not be incorporated into the system. Think about all the lead fall catches that happen every day where the rope (or GriGri) is not loaded on the spine side, but on a random spot in the basket of the biner. I'm not trying to be an antagonist, I just want folks to re-think what modern hardware is capable of and to make decisions based on the massive collection of data that is out there.

I've been thinking the exact same thing.