 Poster: A snowHead
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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If you're in resort at the start of the season many ski schools offer cheapo classes on this too. 
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You need to Login to know who's really who.
You need to Login to know who's really who.
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albinomountainbadger, Very true, courses allow you to actually practice and ask questions. Can't be recommended enough.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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The 1 man deeper burial vid seems illogical? While it might allow him to come in at the level of the vic it seems a lot of energy expended early a long way away. Perhaps if the video showed more and him moving in, taking out progressively bigger columns would make more sense.
Though the first Edgerly paper explains the logic a bit more in creating a broad enough space at the back.
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You'll need to Register first of course.
You'll need to Register first of course.
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Dave of the Marmottes, The main reason I can see is that if digging straight down to a deeper burial then you would not be able to extract the person without digging a massive hole in order to remove most of the snow on top of them, this could be two metres in length if the person is laying flat. Coming in from the side means that when pulling the victim out less snow needs to be removed as a lot of the time you can tunnel and then pull the person out. Also given that the digging is likely to take some time avoiding compressing the victims air pocket is more important than in a shallow burial, often it will be compressed somewhat anyway in shallow depths during probing.
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Yeah I can see all that and it also creates a platform to work on the (unconscious) vic as you pull them out. Just when I look at where the voic is - represented by the perpendicular probe it seems a hell of a long time til I get to them. Probably a case of more haste less speed but it'd be hard to fight an instinct of going in from no more than the perpendicular burial depth across the snow surface. Risk there is that I start not far above the vic's head if its a head downhill burial parallel to the surface (and may compress snowpack) but then the payoff is I get to the airway faster.
Just thinking aloud rather than trying to be right here.
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Dave of the Marmottes, yeah, we always need to question things instead of blindly accepting them. I thought the same way when I saw it, it just seems counterintuitive to start 1.5 x the depth. When they looked at a lot of real life digging scenarios it seems to be very difficult to picture the victim position just by probing. Most of the time you would dig down to the body or a limb first, then a straight hole makes it hugely difficult to free the rest of them. I found that the picture on page two of the case study showed it well, two people dug over 2 metres deep in 15 minutes by starting well below the burial https://s3.amazonaws.com/BackcountryAccess/content/papers/ShovelCaseStudy08.pdf
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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You don't want to be aiming straight down but at 90 degrees to the slope surface; which is why it is useful to put a probe into the snow (at 90 degrees to the surface) even if you haven't located the victim with the probe. If you dig straight down on anything other than a flat surface you will end up well short of where the victim's beacon was located.
Of course if you dig straight down you will soon find yourself working in a hole having to lift heavy avalanche debris, hence the advice of starting downslope where you are moving the debris horizontally rather than vertically despite having to shift more snow to initially reach the victim.
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davidof, Spot on, I meant straight from the surface angle in my earlier post. I think we will organise some digging drills early this year to give people real practice at excavating, in the past we've shown more concentration on using beeps. Areas were roads have been snowploughed and the snow piled up should be good for this as I never like handing around in areas of real avi debris  Even digging show caves gives people practice at digging techniques although these areas haven't been compacted.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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I've just proved it to myself doing some very shaky geometry I think. If I probe a vic at 1m vertically from the surface on a 30 deg slope that point is about 0.87m from the surface. perpendicular from the surface. I then want to go 1.5m downslope if I am going to dig horizontally and not end up above the probe tip. For shallower burials we shortcut this by assuming I'm going to dig down a bit anyway (at least the depth of half a shovel length so I'm fine starting between 0.87 and 1m downslope. For deeper burials I don't want to waste energy lifting snow out of a hole so assuming I'm paddling the snow back I want to start as close to the horizontal level as possible hence 1.5x gives me my proxy.
At the vic's luckiest I hit his face with my first dig, unluckiest I hit the soles of his feet after 1.73m of horizontal digging. Moral of the story - try not to be buried vertically head down but if you can orientate horizontally head down slope (may not be best for eking out oxygen from the body cavity however)
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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Dave of the Marmottes, There can be a slight advantage to having an airbag even if you did get buried, as the bag/s collapse they then create a void. As the bags are deployed by air being dragged into them this also releases air into the cavity. Better than nothing I guess.
One thing when probing, always enter the probe perpendicular to the surface of the snow. This not only gives a precise depth but also has the best angle for finding a victim as your beacon shows you the shortest distance, on a steep slope this may be below the victim. Only stick it in vertically if you are doing a probe only search in a line.
http://beaconreviews.com/transceivers/Probing.asp
I remember probing for a buried rucksack in a spiral and it actually took quite a few minutes to find at only two feet deep. This was with an old style beacon some time ago which was not as precise in our inexperienced hands as the modern 3 antennae ones.
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I've been comparing my new Mammut Element with my old Tracker version 1. I am picking up a signal at almost twice the distance, and the fine search is extremely quick. The only time when both beacons behaved erratically was when I forgot that one was hidden alongside a large bunker housing an electric sub station for the village. Not likely to be replicated in the mountains.
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You know it makes sense.
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Anyone in L2A they do a free weekly Avalanche awareness session. Morning of theory with pisteurs/guide, session in the Arva Park practising with tranceiver and probe (but not shovelling) followed with an off piste session with the guide demonstrating some other techniques too. I'll do it again (3rd or 4th time) this winter.
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Claude B, That is a great service. I remember using the Les Arcs park, great fun and makes you realise how tiring it is to walk in deep snow during a search.
One other good point with digging that I didn't know about... make a note of whether there was an air cavity as this could affect treatment of the casualty.
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FAQ
