Avalanche Airbags

A review of Avalanche Airbag systems.

Preventing or minimizing burial depth is the key to reducing avalanche fatalities. In contrast to other avalanche safety equipment, airbags actively reduce the chance of burial. They work using the principle of inverse segregation. When granular objects of mixed sizes are agitated, smaller objects settle to the bottom and larger objects “float” to the surface.

Provided the airbag is properly deployed, the chances of a complete burial are significantly reduced. European statistics show a 97% positive outcome after more than 220 deployments. A long term Canadian study, using worst case scenarios (multiple burials), put the gain at somewhere between 14-50%. This lower statistic is likely to be due to the scale of the avalanches studied and the higher incidence of trauma related deaths associated with tree skiing in North America. Whatever the statistics, the considered wisdom is that avalanche airbags save lives.

The primary defence against being caught in an avalanche has to be knowledge and an ability to make appropriate decisions about avalanche risk. Avalanche awareness helps avoid venturing onto slopes that are predictably exposed to avalanche risk. On high risk days, going to the bar instead of skiing off-piste is a defensive strategy which substantially reduces the risk of being an avalanched.

Most adventurous skiers will, however, find themselves exposed to avalanche risk. Any safety equipment that reduces the reliance on being found and then dug out, normally within a very limited time window, is a significant contributor to avalanche safety.

…and if you still need a convincer then here is a video of the ABS being used in earnest. Would you have made the decision not to enter the couloir in the first place?

8232_Avalanche au Sautet from TVMountain on Vimeo.

For those putting faith in transceivers and shovels, remember that a minute skiing down can be an hour walk back up in deep or steep snow. Not much of a comfort when your friends are waiting at the bottom of the slope…

There are four commonly available avalanche airbag systems available in the UK and Europe; ABS, BCA, Mammut R.A.S and Snowpulse Lifebag. This is somewhat confused by Mammut now owning Snowpulse and several other manufacturers making bags that contain one of the above systems.

An excellent piece of advice from Mountain Guide Ric Potter to bear in mind, when considering purchasing an airbag, is that there is far more difference between owning and not owning one than there is between the various types. That said, for those of us who do like to analyse the merits of every piece of kit we own, here is a brief rundown of the features that differentiate each system.

  • Activation system – pyrotechnic/mechanical/wireless/speed of fill
  • Airbags – shapes/size/dual/single
  • Filling system (cylinder/cartridge/canister) – nitrogen/air/refillable/non-refillable
  • Interchangeability – the ability to move your airbag system between compatible packs
  • Packs – sizes/styles/comfort/features
  • Price…

THE SYSTEMS

ABS

Owned by German company Peter Aschauer GmbH, ABS has been making avalanche airbags since 1985. If that was the deciding factor we would all be driving around in Peugeots, so apart from having a head start in developing their systems what sets ABS apart is the activation system and dual bag wing design. Dual bags are claimed to offer redundancy (if one rips or malfunctions you still have the other) and are larger than the others at 170 litres. Whilst there was some criticism about this design after test dummies were found to be partly buried face down, most human avalanche victims have finished head up and buried only below their hips.

The detachable activation handle is a pyrotechnic trigger which sends a shockwave to pierce the nitrogen filled canister which is claimed to avoid issues experienced with mechanical activation designs. There is also a wireless activation system which can trigger activation singly or for a whole group over a wide area. The two airbags deploy from either side of the pack. Replacement canisters and activation handles are generally easily available on a swap-out basis from shops (typically for £25). There is also a lighter weight carbon canister available.

ABS Vario 25The two base units can use a variety of zipped on packs  –  the lighter Powder system has two small pack options at 5 & 15 litres whilst the larger Vario system has a small built in pack space and 15, 18, 25 & 40 litre pack options. There is also a 27 litre ARVA option. The ABS packs are stylish have improved in both quality and design for 2013. Other manufacturers using the ABS system include The North Face, and Dakine.

Pack design and comfort is a personal preference – there is no real substitute for seeing and trying out the packs for size. The leg loops attached to the waist belt do prevent the pack being lifted off you in an avalanche but are criticised by reviewers as not being as well designed as other manufacturers.

Price
A typical price for the Vario base unit, 25 litre pack and 2 canisters is £650.

ABS are supplied with two canisters – one of which should be used to practise the activation.

For more details about the ABS system and packs see here: http://www.wildsnow.com/6397/abs-airbag-packs-2012-review.

This video shows the ABS system and a practice activation:


BCA (Backcountry Access)

BCA Float 32BCA has been around since 1994 and is based in Boulder Colorado. BCA currently use a single 150 litre airbag system which is interchangeable between compatible packs. The handle mechanically activates a compressed air cylinder which deploys the airbags behind the head and shoulders. The position of the airbags helps protect the head and neck without compromising peripheral vision and mobility whilst improving the chance of remaining head up in an avalanche situation.

Most paintball and several UK scuba centres are able to refill the cylinders which can be a simpler option than the non-refillable/returnable cylinders used by other manufacturers.

There are two pack sizes – the Float 22 litre and Float 32 litre. The packs are well designed with plenty of features including easy access, waist belt pocket, ski carrying, goggle pockets and hydration routing. Optional extras include a snowboard carrier and a leg loop to prevent the bag being lifted off the shoulders in an avalanche.

Price
BCA is generally the most competitively priced system with as typical price for the BCA Float 32 litre with one cylinder around £600 or less.

BCA Float 32

BCA Float 22

… and a practise activation:

 

Mammut

Snowpulse Guide 30Although the Swiss company Mammut have recently acquired Snowpulse they are still selling their interchangeable airbag system. The R.A.S. (Removable Airbag System) uses the Snowpulse system but allows it to be transferred between compatible packs. The system can be bought on its own or more economically with either the Ride or Rocker packs.

Activation is via a mechanical trigger and the cylinder commonly used in Europe is the 300bar non-refillable, dealer replaceable nitrogen version without a pressure gauge. There is also a slightly heavier refillable air cylinder which has the advantage of being able to be filled from a Scuba tanks. The 300bar refill mechanism for this cylinder is for use in the EU but you would need to anticipate the requirement for convenience and/or a number of refills to make this cost effective.

The shape of the 150 litre bag lies somewhere between the BCA Flow and Snowpulse Lifebag. It is shaped to protect the head and upper back. The top deployment means that the shoulder straps are less bulky than the Snowpulse but it cannot therefore offer the Snowpulse’s additional front protection. There has been some criticism of the Snowpulse system reducing peripheral vision – if you subscribe to this and want additional protection take a good look at the R.A.S.

There are currently 8 R.A.S. compatible packs – Rocker 18 litres, Protection 18 litres, Ride 22 & 30 litres, Ride Short 28 litres, Light 30 litres, Pro 35 & 45 litres. The packs are well designed with strong metal buckles. An integral crotch strap that is routed from the back of the pack, between the legs is threaded onto the waist belt to prevent the bag being lifted off the shoulders in an avalanche. Scott also make a R.A.S. compatible pack.

Price varies with pack size and availability of the combo deals (RAS system + Pack) but expect around £550 – £650. Remember to check whether the price includes the cylinder or not!

If you are interested in the refillable cartridge, the video below provides a step by step run through of the  refilling process:

 

Snowpulse

Established in 2006, Swiss company Snowpulse was purchased by Mammut in 2011. It is likely that there will be a consolidation of the brand, although for the moment, the Snowpulse Lifebag sits separate from the Snowpulse R.A.S. system used by Mammut.

The activation and canister systems are the same as the Mammut described above. The handle has been refined to reduce the chance of snagging whilst retaining easy activation.

The key differentiator of the Snowpulse Lifebag is the top and shoulder strap deployment of the 150 litre airbag. With up to 30% of avalanche fatalities due to trauma, the Snowpulse airbag design is specifically designed to reduce the chance of injury to the head and chest. This ‘head on top’ technology helps float the victim on their back and allows the airbag to form a protective cage round the head, neck and front of the victim. In theory (and only claimed as a potential side benefit by Snowpulse), the design of the bag also increases the likelihood of an air pocket being created around a buried avalanche victim. After the bag has been inflated for four minutes the bag slowly leaks. This can alleviate pressure and supply air to a buried person. With the venturi valves fitted to all the different manufacturers, even nitrogen charged canisters will create substantially more air in the 150litre bags than the 70 litres of gas actually contained in the canister. Snowpulse are currently considering this potential safety feature.

There are 6 skiing/snowboarding orientated packs available which are not sold as interchangeable. The airbag system is not available separately and neither are the packs. Sizes available are the Prorider 15 litre, Heli 22 litre, Guide 30 litre, Lite 35 litre and Tour 45 litre. Each pack is available in two back lengths. The all have integrated crotch straps to prevent the bag being lifted off the shoulders in an avalanche. One issue with these packs is the bulky shoulder straps, which look something akin to a Crewsaver lifevest for obvious reasons. Reviewers have commented that “One of the first things you’ll notice about this pack is that the shoulder straps are bulky. This is because the airbag is inside them. At first this is a pain, but once you’ve adjusted the straps and take the pack out a few times, you won’t notice the straps.”

Although the Snowpulse has some potentially lifesaving additional protection there has been some criticism that the deployed bags restrict visibility and mobility once released. This is subjective and there is some evidence to refute it – see here: http://www.wildsnow.com/5141/snowpulse-lifebag-vision

Price varies with pack size but typically between £650 & £700

Snowpulse Airbag

For a more complete review of the Guide 30 see here: http://www.wildsnow.com/6643/snowpulse-guide-30-review

Flying with avalanche airbags

One last additional consideration is flying with airbags. Both the activation charge of the ABS system and all manufacturers canisters are subject to airline regulations.The International Air Transport Association (IATA) have now approved air travel with the systems in this review. You are advised to make sure that you have the required paperwork for your “avalanche rescue backpack” and inform the airline within two weeks of travel. More details are available  here.