How ABS Airbags Work
The ABS® avalanche airbag is a sophisticated and tried and tested system that aims to prevent you from being buried in an avalanche and to help you survive the fall with the snow masses with as little harm as possible. This may sound easy at first. But how do you manage to stay on top in a real avalanche?
THE BRAZIL NUT EFFECT
When in motion, larger objects will always move to the top. This is also true in an avalanche. The rotating snow crystals creep under your body and push you upwards. But because of your higher weight by volume, this upward movement will then cease and you will sink back into the snow.
In order to avoid being buried in an avalanche, you must increase your volume. With a single pull of the activation handle, an additional 170 l of volume is inflated to help you stay on the surface. In scientific circles, this phenomenon is also known as inverse segregation and is often referred to as the "Brazil nut effect".
The developers of the ABS® system have used these scientific findings to optimize the ABS® system according to the rules of the "Brazil nut effect".
VOLUME ALONE IS NOT ENOUGH
An avalanche is not a liquid like water. It is a granular material, comprising particles and chunks of snow of various sizes, which is why an inflated airbag will not automatically keep you on top of an avalanche. What is decisive is the ratio between additional volume and lifting surface.
An avalanche has three phases: the start, the descent and halt or solidifying phase.
The streamlined ABS® TwinBags generate unparalleled dynamic lift during all phases of the avalanche, preventing you from sinking back into the snow, and during the crucial halt and solidification phase, they keep you in the most horizontal position possible. All these criteria help you stay on the surface. The survival rate of 97% is the proof.
ABS® airbags have shown how they offer the highest survival rate amongst avalanche victims. Of the 262 persons whose ABS® avalanche airbag was activated, 97% survived, 84% remained uninjured and 3% died.
Statistics without ABS
The same accidents involved people who were not equipped with an avalanche airbag. 25% of these people did not survive the avalanche. With an ABS® airbag, you are eight times safer in the event of an avalanche and have the greatest chance of survival.
SLF, known and documented accidents with ABS avalanche airbags, August 2010.