Tuesday, July 15, 2008

Snow Anchor Options - Part I

Believe it or not, but you can use almost anything for a snow anchor.

There is a famous story about a female guide in the Alps who used a lighter as a deadman in the snow. She rappelled a steep couloir with the tiny object as her only protection. A few years ago on an Alpinism 1 course we buried a Powerbar, work hardened the snow, and then proceeded to clip a rope to a cord wrapped around the bar. Four people attached themselves to the rope and then bounced on it. The anchor held...for a few bounces. Eventually it blew out, but the force required to make it do so was tremendous.
While these unusual objects are not recommended, there are objects that we carry that are. A deadman is any buried item that might be used as an anchor point. Deadmen are often generated by commercial pickets and snow flukes. But there are many more options. Skis, trekking poles, packs, stuff-sacks filled with snow, and crampons are all items that we commonly carry that could easily be used as a deadman.

To make a deadman with an object that you would like to bury, first dig a T-slot. This is a hole that has been cut in the shape of a T. Second, girth-hitch or clove-hitch a sling around the object. The sling will run out of the body of the T. Place the object in the hole and then fill it in. After the T-slot is completely filled in, you must work-harden the snow on top of it. In other words, it must be packed down until it is completely flat and hard. Once this is complete, the object will have become a deadman anchor.
Another simple -- yet time-consuming -- snow anchor is the snow bollard. These are an excellent choice for an anchor that will be used for a rappel. To make a snow bollard, one must cut a teardrop shaped groove into the snow. One may then lay a rope into the groove and rappel. When bollards are cut correctly, they work better than anything else. When they are cut incorrectly there is a distinct possibility of failure.

All of these anchors should be considered suspect until they're tested. In order to test an anchor, back it up first. You may use a second deadman, an ice axe, a picket or a fluke to back-up the initial bollard. The back-up should be loosely linked to the line. Should the rope cut through the base of the bollard, the back-up will stop the anchor from failing completely.

Once the back-up has been established, the biggest individual with the largest pack should be sent down first. If the anchor holds the largest amount of weight available, then it's reasonable to assume that the anchor will continue to hold smaller individuals.

Snow anchors are an integral part of mountain climbing. In "Snow Anchor Options - Part II," we'll discuss more options and ideas for both simple and complex snow anchors.

More Information Online:
--Here is a short video on how to place an ice axe as a deadman. Ignore his use of the cord on the picket.
--Here is a short video on the use of a picket in a vertical placement.

AAI Courses that Cover this Information:
Glacier Skills and Crevasse Rescue
Alpinism I: Intro to Alpinism
Alpine Mountaineering and Technical Leadership: Part I
Sierra Intro to Mountaineering

--Jason D. Martin


glen said...

How do you retrieve the picket after belaying?

Jason Martin said...


If you're belaying, you can just pull the picket out. Rappelling is a different story. It's much harder to retrieve a picket if you rap off of it. You're likely leaving the picket behind when you do this...


Anonymous said...

Thanks for an informative article.

I have heard/read quite a bit about people leaving anchors/rope/cordage/webbing/etc. behind on a mountain after a rappel.

I am curious how climbers reconcile this practice with LNT (Leave No Trace) philosophy.

Not meaning to troll, just very curious.

Thank you.

Jason Martin said...

I don't think this is a troll at all. This is a very legitimate question.

There are ways to retrieve a picket during a rappel, but it is an advanced level technique. At some point I will write an article about this...

Climbers have a complex relationship with LNT. One has to get down. It's not uncommon to leave cordage or pins or stoppers on a climb. Sometimes bolts are left. And occasionally a picket or a fluke is left.

Often if a picket or fluke is left, it melts out and is picked up by a party later...

The most ideal situation is to find a way to rappel with out leaving anything. That's part of the reason that a snow or ice bollard is so nice. It's similar with the "no thread" v-thread technique, where the rope is run through the v-thread hole instead of a cord...

It's also important to note that LNT is - as you stated - a philosophy. We all buy into it at different levels. If we have to leave something, hopefully we can pick something up that's extra on the way out...


Elsa said...

Yes great article. I also learned this information from the movie "Frozen" where Christoph uses a snowanchor.