Here's a small video showing this in action if you're interested.
http://www.alpenpro.com/products/ava...last/cover.jpg
Avalanche Blast
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Here's a small video showing this in action if you're interested.
http://www.alpenpro.com/products/ava...last/cover.jpg
Avalanche Blast
Interesting/kewl
That's very cool, but how does it work? Is it just an ordinary balloon bursting that triggers the slides? Must be pretty sketchy conditions for that to occur. I was always under the impression that sonic waves have almost no effect on slide potential. I.e. the old movie myth of people keeping their voices down in avy terrain. And if sonic energy is enough to trigger, then you obviously shouldn't be in that terrain in the first place. Of course in this case they're obviously doing it to protect some pass. And anyway, if a balloon bursting is enough to trigger, then surely rotor wash would be a more effective trigger - just drop the heli down a bit lower over the slope?
OK, read the website and it says stuff about a mixture of gases in the balloons and equivalency to 2.5-4kg charge but it's pretty vague. I'm still surprised that it's that effective. I mean, it's been a while since I did any chemistry, but I've seen a bunch of hydrogen balloons blown up over the last few years and while they bang, they're no stick of gelignite.
Its the same concept as a bomb placed on bamboo being more effective than a bomb thrown in the snow. The blast in the clip is much more effective I'm sure than a standard 2 pound bomb carried by patrollers. This concussion effect is very different than a "sonic" wave. Rarely, avalanches have been known to happen due to hovering helicopters and their rotor wash.
When I was a kid some older kids filled a black weather balloon (about 3 feet diameter) with some gas and connected it to some kind of fuse. It flew fairly low to the ground right towards an apartment building and blew up, breaking several windows from about 50-100 feet. Pretty impressive at the time, although only after running my ass off.
Ah yes, the infamous "Dirtbag Gaz-ex"Quote:
Originally Posted by powderdave