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snow anchor research

Excellent references, Les!

New Zealand's S&R organization does some really excellent work on gear and rescue methods. Thanks for posting this.

Les, Don Bogie,who wrote the snowstake article, also wrote Alpine Rescue Techniques, an illustrated handbook of various rescue methods. Mine is dated 1984 (don't think there's a newer edition)so you won't the newer devices in it, but the basics probably haven't changed all that much.

When I was down there, I was impressed by how much time and money the Kiwis, both officially or through various clubs and associations spent on educating the public on how to enjoy the wild safely. They also spend a lot on rescues and are very organized with things such as the mountain radio network and various SAR outfits. They pretty much go all out when someone goes missing.

No doubt a lot of that is done here as well, but it seemed to be more obvious down there, maybe because the country is smaller and they are so keen on getting into the outdoors.

I did find a new version of Bogie's book-this one dated 1992-it is also listed as Mountain Safety Manual 26, but the only place online that seems to have it is in NZ.

Hey Les, that's a really interesting article. Some of the engineering terminology makes my head spin a bit but it's reasonably clear...vertical placement of stakes, clipped at the middle with a steel cable are much stronger than other configurations. They're also as strong (and much quicker to build) than a T slot anchor. One high profile Kiwi guide (Gottleib Braun Elwart ?sp) has been pushing the mid clipped stake for years but this seems to be the first hard data on it.

With typical snow conditions in NZ you end up digging a hell of a lot of T slots if you're pitching, so this could save some serious time. Will have to give it a practice!

Andrew, When I took the TMC (beginner's climing class) at Alpine Guides at Mt. Cook, we used both snowstakes and the snowfluke, deadman or whatever they call it. I think both had a length of aircraft cable fixed to them. The snowstake also had holes down the length of it so you could fix a biner to it in the middle. We were told to make sure the cable was right down at snow level or even below. We also learned to use the T-slot with either the snowstake laying in the slot or an ice axe with a piece of webbing around the shaft. We also learned to make a snow bollard in the event that we didn't have a snowstake, but I think those are a last resort.

Hi Tom, I did a couple of courses in the mid 90s and the techniques you describe are the bread and butter of the snow anchors. What this paper is describing I think is something a little bit different. The 'snow pig' type stakes with a swaged centre mounted cable have been around for a fair while but everybody I've seen/spoken to uses them in 'diving mode' (i.e. placed back at a steep angle in soft snow, and in a position to 'dive' when loaded) whereas, if I'm reading it right, these guys are arguing that they're better used kind of 'upright deadman' anchors with the cable clipped in the middle a foot below the surface of the snow and either running through a thin cut slot or through a slot that you've excavated and then repacked,depending on the snow conditions. This is supposed to be just about as good as a much more complex and time consuming T slot arrangement.

It's difficult to know how much difference this would all make in practical terms because I always figured that the stresses on a snow anchor wouldn't be that large...but they're arguing some quite largish figures that seem to make sense.

I went back and read the article fairly carefully. It appears that the best angle of the stake depends on the type of snow. Interesting reading, although I skipped over the math. The pictures said enough. It's all about leverage.

September 30, 2020
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