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Avalanche Flotation Devices (AFDs) have been around for a long time now, thanks to inventer Peter Aschauer from Germany. The first tests of an inflatable bag filled with gas floating to the surface of a moving avalanche were done in the 1980's. Aschauer's company, ABS Systems, has manufactured and sold AFDs for decades now, and it is a proven lifesaver. What happens to an AFD in an avalanche is called “inverse grading” by the snow scientists. The theory is that the inflated device sheds off the snow that is on top of it in a moving mass of snow, as the AFD is lighter and larger than the grains of snow that are trying to bury it.
This physical property of inverse grading has been proven by the dozens and dozens of lives that the Aschauer ABS system has saved over the years.
AFDs generally find the surface in the lower 1/3 of the avalanche, well over half way through the slide. When snowmachiners, skiers and snowboarders start avalanches, the initial rush of moving snow almost always buries both the victim and the AFD. As the avalanche nears the midpoint of its run, the AFDs generally begin to work their way to the surface and to emerge on the top of the moving snow. The AFDs cause the victim to advance downhill slower than the leading edge of the slide, retarding the downhill movement of the victim as well as dragging the victim to the surface. As the vertical center line of the avalanche is moving faster than the outside edges of the slide as it progresses down the mountain, this causes the AFD and the victim to be pulled off to the side of the slide as it advances down the hill.
The majority of AFDs are found fully exposed above the surface after an avalanche, the majority of AFDs are found on the sides or outside edges of the slide after the avalanche and the majority of AFDs are found 1/3 to ¼ of the total distance of the slide uphill from the stopped leading edge of the avalanche.
Several other variations of AFDs have been produced over the years, including the K2 Avalanche Ball, which had a long tether attached to the victim. The idea with the K2 Avy-Ball was that the victim’s rescuers (hopefully fellow snowmobilers or skiers) would find the AFD on the surface and follow the tether to the buried victim.
Another recent AFD is the SnoPulse system (like the ABS system, also encased in a back pack) which inflates around the upper torso and head of the victim.
We have been working for the past 8 years on yet another type of AFD, an avalanche vest we call the Avi-Vest. Our vest would be worn over the jacket or snow-suit of the user and hold only a flotation system, a shovel and a probe. We are doing our prototype testing again this year in Invermere, British Columbia and we’ll post the results here.
No matter what type of Avalanche Flotation Device you chose, it’s crazy to be out there in avalanche country without the only proactive piece of avalanche survival gear there is……
This physical property of inverse grading has been proven by the dozens and dozens of lives that the Aschauer ABS system has saved over the years.
AFDs generally find the surface in the lower 1/3 of the avalanche, well over half way through the slide. When snowmachiners, skiers and snowboarders start avalanches, the initial rush of moving snow almost always buries both the victim and the AFD. As the avalanche nears the midpoint of its run, the AFDs generally begin to work their way to the surface and to emerge on the top of the moving snow. The AFDs cause the victim to advance downhill slower than the leading edge of the slide, retarding the downhill movement of the victim as well as dragging the victim to the surface. As the vertical center line of the avalanche is moving faster than the outside edges of the slide as it progresses down the mountain, this causes the AFD and the victim to be pulled off to the side of the slide as it advances down the hill.
The majority of AFDs are found fully exposed above the surface after an avalanche, the majority of AFDs are found on the sides or outside edges of the slide after the avalanche and the majority of AFDs are found 1/3 to ¼ of the total distance of the slide uphill from the stopped leading edge of the avalanche.
Several other variations of AFDs have been produced over the years, including the K2 Avalanche Ball, which had a long tether attached to the victim. The idea with the K2 Avy-Ball was that the victim’s rescuers (hopefully fellow snowmobilers or skiers) would find the AFD on the surface and follow the tether to the buried victim.
Another recent AFD is the SnoPulse system (like the ABS system, also encased in a back pack) which inflates around the upper torso and head of the victim.
We have been working for the past 8 years on yet another type of AFD, an avalanche vest we call the Avi-Vest. Our vest would be worn over the jacket or snow-suit of the user and hold only a flotation system, a shovel and a probe. We are doing our prototype testing again this year in Invermere, British Columbia and we’ll post the results here.
No matter what type of Avalanche Flotation Device you chose, it’s crazy to be out there in avalanche country without the only proactive piece of avalanche survival gear there is……
