Thread: SRS Airbag check at 10 years

Originally Posted by bsperka

BTW, the explosive force in an airbag is about the same as a claymore land mine, so anyone with their feet on the dash (passenger side) or legs on the seat / folded in front of them will die a very painful death from internal injuries (legs into the chest and abdomen etc) if it deploys with them in this position.

Be careful around them and treat any maintenance around them with lots of respect, as they will take your head off (figuratively or in reality) if they go off with you too close to them and you are not in a normal sitting / steering position.

I know I'm replying to a very old post - but I really need to correct this statement.

A claymore mine (and no, it's not a land mine - it's a command detonated directional mine) has 1 1/2 pounds (nearly 700g) of C4 plastic explosive in it. If you detonate the best part of a kg of C4 inside a car you won't be worried about the injuries listed above - and you certainly won't have a painful death. You will be a nasty paste on the inside of a car that has tried to become spherical from the intense instantaneous internal overpressure - before it bursts open.

While I fully support everyone taking great care around SRS pyrotechnics (don't forget that seat belt pre-tensioners should be included), to claim that the SRS airbag has the same force as a claymore mine is just ridiculous.

To quote from Wikipedia:

"An igniter starts a rapid chemical reaction generating primarily nitrogen gas (N₂) to fill the airbag making it deploy through the module cover. Some airbag technologies use compressed nitrogen or argon gas with a pyrotechnic operated valve ("hybrid gas generator"), while other technologies use various energetic propellants."

and

"The azide-containing pyrotechnic gas generators contain a substantial amount of the propellant. The driver-side airbag would contain a canister containing about 50 grams of sodium azide. The passenger side container holds about 200 grams of sodium azide."

200g of a pyrotechnic chemical designed to rapidly inflate a bag with gas is a very long way from a lethal high explosive charge that propels 700 ball bearings out to 100 metres - with a lethal range of 50m.

I've seen claymores demonstrated - and I can assure you that you don't want to be near them when they fire.

I haven't seen an airbag detonate - and hope I never will - and I fully endorse all the safety measures in the manuals; but I don't endorse trying to scare people away from them through ridiculous overstatements.

I asked an ex navy ordance officer about the explosive force. He indicated it was an exaggeration as its a different type of explosive force. Designed to generate lots of gas quickly, not to explode as such. The reason we have cheap airbags is due to an explosive company in the USA (hand grenade manufacturer IIRC) building a cheap, reliable way of creating a lot of gas in a short time. Not withstanding the above, the statements re injury and death are still valid.