Avalanche bags work on a different premise than avalanche transceivers. Rather than
making it easier for your partners to locate you after you are buried, airbags are designed
to reduce, or eliminate, your
burial.
Of course, an even better strategy is to avoid being involved in an avalanche in the
first place (please take that avalanche course).
Avalanche airbags are integrated into a special backpacks. The airbag system contains
a compressed gas cylinder that inflates one or two airbags which deploy when you pull
a rip-cord on one of the shoulder straps. The increased volume of the inflated airbag(s)
reduces, or eliminates, the burial depth. The reduction in burial depth is based on
the “marble effect” which says that if you shake a bowl of marbles, the larger ones
will rise to the top. The airbag makes the skier, or sledder, larger so he will remain
closer to the surface. Airbags inflate in two to four seconds. All airbags include shoulder,
chest, waist, and leg straps. The leg straps must be worn.
The data endorsing avalanche airbags is strong. According to the
Swiss Federal Institute for Snow and Avalanche Research,
between 1990 and 2007 there were 151 people who were lucky enough to be wearing (ABS-brand)
airbags, yet unlucky enough to be caught in avalanches. Of those fortunate, or unfortunate,
folks, 66 (44%) were not buried, 63 (42%) were partially buried, 19 (13%) were completely
buried but the airbag was still visible on the surface, and only 3 people (2%) were
completely buried with nothing visible (at least one of which was struck by a secondary
avalanche). Of the 151 people, there were only 2 (1.3%) fatalities. Those numbers are
vastly better than the statistics for people wearing avalanche transceivers. Of course,
you must wear an avalanche transceiver in addition to an airbag in case the airbag doesn't
keep you on the surface or a secondary avalanche occurs.
Airbags use the venturi effect
which allows them to put more air into the bags than is stored in the compressed gas
cylinder. The physics is beyond me, but suffice it to say that by having the compressed
gas forced through a constricted nozzle, the rapidly-moving gas can draw in atmospheric
air that also fills the bag.
Airbags have been used primarily in Europe with limited world-wide distribution.
However, with Backcountry Access, the company that makes the popular
Tracker avalanche transceivers,
now in the airbag business, it's likely that we will see many more airbags in North
America. Snowmobilers seem to have taken to the airbags more quickly than the backcountry
ski and snowboard community. Maybe that's because snowmobilers have already invested
serious dough into their sleds, maybe it's because the weight isn't meaningful
when you have a rocket taking you up the mountain, or maybe it's because they're
quicker to endorse new machinery.
There are a few downsides to airbags. First, they're pricey. At $685, the
Float 18 is the least expensive. And you can easily spend twice that
on other brands. Second, there is additional weight for the airbags (although the weight
has dropped
significantly
over the last few years). Another disadvantage is that they limit your selection of
backpacks, forcing you to choose between a handful of models versus the hundreds of
packs that are available without airbags. It's likely your airbag equipped backpack
won't include your favorite feature, be it a hydration sleeve, a padded goggles
pocket, a stash zipper on your waist belt, that slick tube for your probes, zipper access
from the front of your pack, or a myriad of groovies that you've come to love.
There can also be challenges travelling on airlines with the compressed gas cylinder.
The FAA has specifically approved avalanche airbags with pressured cylinders, although
many individual airlines have not (and airport security personnel may be unfamiliar
with avalanche airbags). ABS recommends that you contact your airline
at least 14 days in advance. BCA suggests that you discharge the
cylinder at home and then locate a refill center at your destination. Finding a location
to refill your cylinder, after flying or deploying, can be challenging (especially airbags
that are refilled with nitrogen).
With the impressive survival data, it is possible that most backcountry travelers will
be wearing avalanche airbags in the future. But given the current price and refill limitations,
I expect their acceptance will be gradual. That said, for fulltime folks who spend day
after day in avalanche terrain, I'm thinking about patrollers and professional guides,
wearing an avalanche airbag seems like a no-brainer.
The
company "Peter Aschauer" (a.k.a. ABS) released the first commercial avalanche
airbag in 1985. They've developed a number of models with both single and double
bags. The current products, known as the ABS Vario-Line, include the Freeride (a small
pack intended to store just the airbag) and the Escape (larger backpacks with built-in
airbags). The Vario-Line deploys two airbags to the side of the pack.
The two airbags are inflated using nitrogen. The bags are independent (if one is
punctured, the other remains inflated).
The ABS cylinders and trigger handles must be refilled by the manufacture. You can
purchase replacement cartridges and trigger handles where you purchase ABS airbags.
ABS recommends that you return the unit to a service center every three seasons for
a general inspection.
ABS has significantly expanded their distribution network in the last two years.
Visit their
dealer locator to find a dealer.
Backcountry
Access, the folks that make the popular
Tracker DTS and
Tracker2 avalanche transceivers,
developed the Float series of airbags.
The Floats are refilled with atmospheric air using a scuba-to-paintball fill adapter,
rather than requiring a specific gas (e.g., nitrogen). The BCA
website lists 41 refill
centers in the USA and 13 in Canada. The refill centers range from backcountry equipment
retailers and fire stations, to paintball and scuba shops. The cylinders can also be
refilled by returning them to BCA in Colorado.
The ease of refilling the BCA airbags, especially in North America, is sure to add
to their popularity. The addition of two new sizes in 2011 should increase the
Float's popularity.
Mammut
Mammut, the company that makes the Element
and Pulse avalanche transceivers, entered the
airbag industry in 2011. If the airbags are anything like the transceivers, they
should be excellent.
The Snowpulse airbags are unique,
in that the airbag is designed to envelop your head, providing protection from trauma.
ABS and BCA state that
losing
peripheral vision isn't a good idea, because after deploying the airbag you will
still want to attempt to ski, or ride your sled, out of the avalanche. "Deploy soon and
exit quickly." Time will tell whether the survival rates are better for the Snow pulse's
wraparound style or the BCA's Float.
The Snowpulse packs come in two torso sizes (medium and large). Many of their packs
include a hydration pouch and hose guide.
The Snowpulse website says that you can refill the cylinder yourself ("requires
training, a source of air under pressure, and an adaptor"). They have the complete
instructions online, but it looks a little beyond what should be expected from the
average customer.
The Snowpulse uses a different air cylinder depending on whether you are in Europe
(4,350 psi) or non-European countries (3,000 psi).
They list only one dealer in North America (Mountain Sports Distribution, in Canada).
Videos
Researchers at the Fraunhofer Institute for Manufacturing Engineering
and Automation, in Germany, have been working with ABS Peter Aschauer
to create a wireless, remotely triggered airbag. This causes all airbags to be deployed
if any one airbag is deployed as shown in this video.
The AvaLung is a snorkel-like device that you put in your mouth. You then breath
in oxygen-rich air from the front of your body and exhale the CO2 saturated air near
your back. (The excessive CO2, not the lack of O2, is what asphyxiates you.) The challenge might
be getting and keeping the mouthpiece in your mouth, but there are several
documented
cases of survival due to the AvaLung.
On December 14, 2010, Black Diamond announced a recall of some AvaLung packs that
were manufactured during 2010, because the intake tubing on certain 2010 AvaLung
packs may crack under extremely cold temperatures. You can determine if your AvaLung
pack has been recalled by checking the PO number on the tag within your pack.
Learn more here.
This is a backpack-like device that contains a deflated balloon. When an avalanche
strikes, you pull a rip-cord to inflate the balloon which is tethered to the end of
a 12 meter cord. The balloon remains
above the snow. Rescuers follow the cord to the victim. It sounds like a lot of shoveling...
Visit the manufacture's
site.
Don't confuse this with an avalanche air bag, above, which prevents you from being
buried in the first place.
burial.
Of course, an even better strategy is to avoid being involved in an avalanche in the
first place (please take that avalanche course).
Backcountry
Access, the folks that make the popular
losing
peripheral vision isn't a good idea, because after deploying the airbag you will
still want to attempt to ski, or ride your sled, out of the avalanche. "Deploy soon and
exit quickly." Time will tell whether the survival rates are better for the Snow pulse's
wraparound style or the BCA's Float.
