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  1. #1
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    Nov 2011
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    Safe travel techniques on steeper avy terrain

    Question- how do people prefer to travel in, say, a group of 2 on steeper, avy terrain? Example: an open headwall, say an average of 38-40 degrees or so that you're either skinning up/French stepping up and then switching to front pointing/booting/post-holing. (This just came up for me this past weekend.)

    Other safety considerations aside, conventional wisdom clearly dictates that you don't pass above any of your partners and that you space yourself out. Given that most terrain of this style requires switchbacks to travel up, you have a few hazards to mitigate- first, crossing above/below your partner (which really is just a way to avoid simultaneous burial/being in the same place when a slide occuers), and second, overweighting a particular area of the snow by clustering up between crosses. So as I see it, you have a few options, as I list below.

    1) Everyone climbs an entirely different region of the headwall. Good because everyone is spread out, bad because you're 2x more likely to find a weakness, and a big slide across the whole aspect would take you all out anyway, and everyone is always breaking trail, and you're tracking up the entire slope. (This seems silly to me and I am only including it for discussion).

    2) Go from point to point of the switchbacks, one at a time, meeting at each corner before heading out again. Good here as no one is crossing above/below anyone, but bad because you cluster (albeit briefly) in the end of each switchback and have 2x the weight on the snow, and also you're both in the same place for a few moments before the next person leaves.

    3) Travel "out of phase:" defy conventional wisdom and be at opposite ends of the switchback, but cross above/below in the middle. Good because you move past each other quickly and the snow isn't weighted in any one place, but bad because there's burial potential when you're transiently both in line.

    4) Climb the entire slope using one skintrack/bootback/path, but one at a time, with one person waiting at the bottom until the other climbs in full. This is undoubtedly the safest/most conservative way, but it's pretty impractical and obviously takes 2x as long, which introduces issues of cold and reduced speed and other associated issues. Also if your group is 3-4, then it's basically impossible.

    So- a classic tradeoff. Personally, #'s 2 and 3 make the most sense to me, and I tend to do #2, but am thinking more about #3 as being an option as well in spite of the fact that it defies conventional wisdom.

    What do others do in this situation? What's the safest approach? Does my question make sense?

  2. #2
    Join Date
    Dec 2005
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    Front Range, CO
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    5) travel up a ridge

    It seems to me that traveling up prime avy terrain using switchbacks is only appropriate in circumstances where the avalanche risk is low, and therefore it should not make a lot of difference in the phasing of the skiers going uphill relative to each other. If danger is higher than low, then a safer approach route should be considered. If a safer option isn't available, then exposing one at a time seems prudent.

  3. #3
    Join Date
    Dec 2004
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    FTW.....

  4. #4
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    Oct 2008
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    Colorado
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    IMO main mitigation technique needs to be to avoid traveling on suspect slopes when there is significant danger. The techniques that you outline will each have their +/-s.

    I'm generally hesitant to travel up steep headwalls or up couloirs in anything but lower end danger. Even then I'd probably choose to travel on lower angle terrain if available. If not then I'd probably be booting/cramponing in most steeper terrain so I'd opt for staying as much to the side or out from beneath areas that I could anticipate avalanching. If possible one at a time between islands of safety, but then time constraints and terrain would limit how much that can be used.

  5. #5
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    SnoqWA
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    I get the predicament. There's no alternate route available, and you've deemed the avalanche danger low enough to justify climbing the slope, but still want to take reasonable precautions to minimize risk.

    There's no perfect answer and the safer ones are the slower ones. I usually use #3, traveling quickly when above/below another person and pausing at the edges of the slope.

  6. #6
    Join Date
    Oct 2003
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    One piece of information to add:

    Statistically speaking, you are safer if you use an existing (good) skin track or boot pack rather than making a new one for each person. Most groups caught while ascending were breaking new track.
    Quote Originally Posted by blurred
    skiing is hiking all day so that you can ski on shitty gear for 5 minutes.

  7. #7
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    Nov 2011
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    Boston
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    Thanks for the discussion... good points and good thinking here.

  8. #8
    Join Date
    Nov 2005
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    This seems a little academic without an exact slope/situation but it also sounds familiar. Obvious preference for #5, but assuming that's out and you're still going, I think the difference between #2 and #3 kind of comes down to your skintrack: you want to meet or cross over/under at the safest point, so the question becomes, are the switchbacks at the safest part of the slope (no outcropping/wall, convex rollovers, extra steep spots, or, most important, signs of local instability) or is the first guy turning to avoid a problem? Seems clear that the switchbacks SHOULD be in safer spots, but if some local sign of instability shows up that would change the plan (maybe in a big "turn back now" way, maybe in a way that just says "stay off that spot, it's thin").

    I'm thinking if you work this out to the point of a plan (and still decide to go on) then it might be best to wait until the lead person stops where he deems it safest (whether that's at a turn or not) and then catch up. Slight variation on #2, I guess. Thoughts?

  9. #9
    Join Date
    Jan 2008
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    truckee
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    One other thing to factor in is whether the avalanche risk is increasing with time--due to warming, wind-loading, etc. If it is the speediest approach might be the safest. (Presumably this is a multi-day trip, run out of food, turning back or sitting still is not an option, otherwise you would go somewhere else or stay home, right?)

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