There have been several comments on the dangers of airbags, these have appeared in the fire brigade strike thread. It has occurred to me before that they could be dangerous, after all they have an explosive charge to operate them.
It would be interesting to hear comments on the matter.
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Airbags use a chemical 'mix' which produces a large quantity of gas in a very short time - obviously vital to have extremely rapid deployment in an accident situation. It could be described as an an 'explosive' charge, and I believe the deployment can sound like an explosion when it goes off.
Dangerous? Hm. What would you rather hit - the rather rigid steering wheel or an air bag? I realise there has been publicity from America, but few drivers there use seatbelts. There are also the well publicised dangers with people sitting too close to the airbags, and the child seat issues - almost all avoidable. On balance they are a benefit. I've a friend who had a major accident. Considerable damage to his pelvis (his leg was hard on the brake) but no question the seatbelt and airbag combination saved him from further injury.
Regards
John S
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Airbags add extra weight and bulk to a car, which increases stopping distance and reduces manoeuvrability. Some may say this is marginal but in a 2 car collision the effects are doubled of course.
There are therefore a number of crashes which would have been avoided altogether without airbags.
The pressure is placed on manufacturers to make their cars safer for those inside, meaning bigger and heavier vehicles. Leading to the morally unacceptable situation where they become increasingly deadly for those outside.
It's time to think again, and differently.
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>>Airbags add extra weight and bulk to a car, which increases stopping distance and reduces manoeuvrability.
As do spare wheels, jacks, tools, shopping, passengers, larger drivers and of course a full tank of fuel.
In fact, lets all only fill our tanks half-full and then the weight saving will more than balance the airbag and we'll all be safe again.
Also, all drivers on diets, no spare wheels, no suitcases or shopping.
On your rather more sensible point....
>>The pressure is placed on manufacturers to make their cars safer for those inside, meaning bigger and heavier vehicles.
I think its appropriate to make the cars safer, but not to shift the responsiblity for careful behaviour.
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Right you are, but airbags have only one purpose - safety.
If you start out thinking purely of safety, I suggest most people could come up with a better resolution to the inevitable dangers of driving.
Without any of the many drawbacks of the airbag.
In about 5 minutes.
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Not sure that I could.
Other than people wearing proper seat belts correctly.
On the other hand I was once in a Clio Williams which hit a tree. We walked away unharmed, although I smoked about 50 cigarettes in 3 minutes and couldn't talk sensibly for about a month.
Looking at the car afterwards, it not only shielded me from goind forward and hitting stuff, it also shielded me from all the stuff (windscreen, bonnet, tree etc.) which came my way.
I can;t think of anything else which would have done that.
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although I smokedabout 50 cigarettes in 3 minutes and couldn't talk sensibly for about a month.
When will the month be up?
:-)
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When will the month be up? :-)
Blimey !! Needling the moderator. You'll be putting your head in an alligator's mouth next :-)
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Yeah - just a joke and I'm sure it's taken in the spirit intended.
I know Mark's task is thankless.
Tomorrow I'll post my ideas and get what I deserve I expect!
(Assuming I still can!)
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Yeah - just a joke and I'm sure it's taken in the spirit intended.
Yeah. HJ's site, like most male environments thrives on a bit of gentle ribbing! All the better if it's very funny - which it was.
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These are my own opinions, and not necessarily those of all Toads.
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Yeah. HJ's site, like most male environments ...
How do you know Maz isn't short for Marion, Toad?
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Abusing a man with *the* edit button ! Good grief.
You wanna be careful or you'll be writing about pink furry dice before you know it. Ask Dynamic Dave !!
M.
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>> You wanna be careful or you'll be writing about pink furrydice before you know it. Ask Dynamic Dave !!
Yes indeed. You don't want to go upsetting Mark, or the pink furry dice will hit the fan and you'll be out of here quicker than pink furry dice off a shovel :o)
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Two years ago my Volvo 240 was written of following a collision with a slow moving Volvo 940. My part of the accident was avoidable, the 940 had already hit two other cars before demolishing mine. The airbag inflated when the 940 hit the first car, the driver admitted to losing control because the airbag blocked her vision and she was unable to avoid the second car and mine. Mind you she did hit the first car side on at 40mph and the airbag probably saved her some grief in the first instance.
The accident happened because one car stopped at a x-roads and turned his steering wheel to the right to await the passing of oncoming traffic. Sadly the following vehicle misjudged things and bumped the stopped car into the path of the aproaching 940 and it all went wrong from there. Apart from bruises no one was injured.
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There have been several comments on the dangers of airbags, these have appeared in the fire brigade strike thread. It has occurred to me before that they could be dangerous ...
And driving around with a tank full of highly volatile and flammable fuel isn't?
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And driving around with a tank full of highly volatile and flammable fuel isn't?
Actually if you ask a few people round these parts they'll tell you supermarket fuel barely burns at all!!!! ;-)
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These are my own opinions, and not necessarily those of all Toads.
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Actually the fuel tank is quite dangerous I suppose. Two Police Officers were killed not that long ago when a van hit their Mondeo and the fuel tank exploded. Thankfully I don't think fuel tanks explode on a regular basis. At least not as often as TV and films would lead us to believe...
As far as the airbag is concerned, I can't think of a better way to hel pprevent injury, short of instantly filling the car with a foam that prevents people moving too much in an accident, just like the stuff in Demolition Man. But then people would complain about getting suffocated! :)
About the airbag blocking the woman's view, I may be wrong here, but aren't airbags designed to deflate during the impact, so as to prevent you from bouncing off them and getting flung out of the rear windscreen? :) I've never seen one where the airbag stays inflated after the bump...
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Actually the fuel tank is quite dangerous I suppose. Two Police Officers were killed not that long ago when a van hit their Mondeo and the fuel tank exploded. Thankfully I don't think fuel tanks explode on a regular basis. At least not as often as TV and films would lead us to believe...
All the more reason for diesel!
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All the more reason for diesel!
But doesn't diesel ignite by compression? As the police van hit the rear end of the Mondeo at high speed, the diesel tank would have been crushed, hence compressing the diesel inside, thus BANG
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dammit Dynamic, and I'd just been feeling so pleased that my diesel car was never going to explode!
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dammit Dynamic, and I'd just been feeling so pleased that my diesel car was never going to explode!
No need to panic HF. I'm sure your car would have stopped long before the fuel/air ratio in your fuel tank got as low as it is in the cylinders when they go bang :-)
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Thanks for all the comments, I take the point about the fuel, but unfortunately the car would not run without it.
however driving round with four small explosive charges (airbags and seatbelt pretensioners), still does not appeal to me.
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I personally would not like to go back to owning a car that wasn't filled with explosive devices such as these as they are not known to go off accidentally, except maybe in a very, very, very rare case. However, they have been proven to reduce injury in many, many crashes. :)
Besides, what worries me far more is the idea of doing 70 mph with only four inflated pieces of rubber between me and death. If one of them was to receive damage and blow out it's time to make an appointment with the undertakers... Far more people have been injured or even died this way...
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Airbags are a relatively new fitment to mass market cars. The real dangers will come when the vehicles are ten years or so old and on their fourth or fifth owner with servicing neglected. By then whatever trigger mechanism they deploy could have degraded to the extent where accidental discharge becomes a real possibility, with disasterous consequenses.
I would feel far safer in a car with more efficient seat belts and a steering wheel that is built to retract on impact than a device which could explode in my face without warning. It has happened to people already, and will do so more frequently as modern cars reach banger status.
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Having read some of the uninformed drivel above:
Having spent 18 years in the motor industry developing trim & door components I have seen many test crashes, airbag deployment tests and videos of crash tests. I've recently been involved with the development of trim to work with side air curtains and to meet US head impact legislation. I've also seen much of the numerical data from crash test dummies.
Would I rather drive a car with or without air bags? Well, I enjoy my life and would like to keep it intact. Airbags every time - they reduce the severity of the accident (to the occupant - not the car) MASSIVELY. The car is expendable.
The only other solution would be to prevent the accident in the first place. Not easy.
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I remember lots of arguments being made in the same vein when the wearing of seatbelts was made compulsory. 'Better to be thrown clear', 'will get trapped inside a burning car' etc. Nonsense of course, in 999 times out of 1000 both seatbelt wearing and airbags do nothing but good.
However, I do agree that when these cars are in the banger market problems could arise, though only from ham-fisted home mechanics tinkering with something they don't understand. An interesting point made about the life of the propellant. Does it have a design life and if so how long? Anyone know? And if it does, surely manufacturers should point out that it will need changing after x years.
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I think most manufacturers recomend airbag replacement after ten years. But after ten years the car will be on it's umpteenth owner and the handbook and any service records will be long gone.
Any servicing may well consist of a bit of DIY bodgery, and that is when the dangers occour.
I agree that in an accident an airbag will save a lot of injury, but I personally would prefer the development of passive safety devices as opposed to something that is in itself a danger should it malfunction.
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Just thought I'd mention that a British man invented and patented the airbag many years ago but couldn't get any motor manufacturers interested in it and so he let the patent lapse. If only he'd waited a few years until we started to get serious about car safety -- he would have made a fortune.
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My Fiesta recommends airbag replacement after 15 years. Of course no one would ever actually do this because by then the airbag would cost more than the car is worth.
I wouldn't worry too hard about accidental depolyment. Ford Mondeos have had these devices fitted as standard equipment from day one and the oldest examples are now almost 10 years old. I haven't heard of any problems as yet with the trigger mechanisms which are AFAIK electrical and hence not liable to become unstable. Other cars have had them for even longer and again, I still haven't heard of any age related accidental deployments.
I thought that the reason they recommend replacement is that they are worried that the chemicals which depoly the airbag may become ineffective and not go off any longer.
Actually, this reminds me, didn't the new Mondeo have a recall? Something to do with random activation of the curtain airbags? Believe it was fixed though...
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For some discussion on the need to change airbags after 10yrs see
www.honestjohn.co.uk/forum/post/index.htm?v=i&t=70...4
Believe me, there is no need to change them.
As for airbags being dangerous in themselves: only when people ignore advice and sit far too close or put rear facing child seats in front of them. To this end manufacturers are now fitting sensors that can detect "out-of-position" occupants and turn the bag off if necessary. Of course, if you are out-of-position at the moment of an accident you will not benefit from the airbag and will be more severely injured than if you had been sat in the seat properly.
There are no verified cases of hearing damage from airbag deployment - despite the urban myth.
Consider this: if airbags really were dangerous there would be loads of punitive damage claims in the USA and airbags would be being removed from new cars for fear of the litigation. Indeed it is actually illegal to deactivate an airbag in the US except under very strict circumstances. Its generally reckoned that airbags save around 1000 lives a year in the US. In 1999 they killed 12 - and 10 of those were sat VERY close to them at the time of deployment - remember seat belt usage is very low in the US.
Of course, as illustrated in one of the replies above, airbags can only protect against the effects of a primary accident - you are still at risk from secondary impacts. This affects only a small proportion of accidents.
Have a look around this site: www.nhtsa.dot.gov/
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Re "trigger mechanisms"
trigger mechanism in older fords is a ball bearing in a sticky cardboard tube, in crash ball bearing moves and sets off bag
the alternative "electronic" version is essentially some hair like interweaving wires done at microprocessor scale, that when they touch set the bag off
would have thought any explosve at 15 years should be checked out - but doubt whether they are set up for inspection etc leading to replace anyway advice
but economics means it wont be happening in practise
i think as some of these become classics and only used for very low mileages the best approach would be to remove bag and put cover back with just padding underneath
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The trigger in the newest cars is even better than this. Some cars have as many as eight proper accelerometers strategically placed around the vehicle. These feed an input to the "brain". In a crash they measure the severity precisely and the brain looks at the signal from all sensors and decides which bags to set off (and when). In some cars the bag deployment rate can be regulated too.
As I've pointed out already, airbag manufacturers have found no measurable fall off in performance on 15yr old airbags removed from real old cars.
There is no way you can check the pyrotechnic charge.
Removing the airbag in the means you describe will render the car unable to pass an MoT. The SRS brain will detect that the bag is missing and keep the SRS warning light ON. Car fails MoT. Since there is no degradation in performance over an exceedingly long lifetime why on earth would anyone want to remove such a life saving device from their car?
You might like to know that it is only the steering wheel airbag that is pyrotechnically inflated. Curtains and bags in seats use a reservoir of stored gas.
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Soes anyone know what the charge is? Some naval gun propellants used to become unstable if kept too long in magazines and quite a few ships suddenly disappeared.
Since this tended to happen with poor magazine cooling, perhaps we would learn of any such risk first from hotter places?
Tomo
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well as the US has had airbags longer than us, and they have some of the hottest places on earth - try Arizona for a start- we'd have heard of exploding airbags by now (and as someone said, the manufacturers would be sued).
I think the ships magazines' instability was when some explosives or propellants started to "sweat" - I understand WW2 bombs in the ground using nitroglycerine based explosives do that - found on discovery after 30+ years! Remember that explosives chemistry was pretty crude up to WW2 - one look at any munitions factory with its blast doors, wide spaces and occasional relics of explosions is enough!
Needless to say, the explosive used to expand airbags are not based on nitroglycerine!
" Gas generators, for airbag inflators. Airbags are car-safety-devices that use a pyrotechnic inflator, based on the combustion of s**ium azide (NaN3) with an oxidiser, rapidly producing a great quantity of nitrogen gas that inflate a nylon or polyester bag in some 50 milliseconds (inflates at 100 m/s). They commercially started in 1975 in USA, and widespread to all new cars in late 1990s. Other explosives have been tried without much success (ammonium nitrate and ballistic powders). Airbag deployment is harsh: it generates some toxic substances (Na2O; NaOH, a strong alkali that may cause blindness; and hydrazoic acid, that is a toxic and explosive gas), it generates a white smoke of talcum powder used to lubricate the deployment), and it usually causes burns to passengers, either by friction, chemical attack or high temperature. In case of accident, beware of undeployed airbags!; turn off the engine and disconnect first the negative battery cable, but even so, static electricity may deploy it, and the autoignition temperature for NaN3 is 300 ºC. A low combustion temperature (2000..2300 K) is preferable to avoid massive formation of toxic CO and NO. If NaN3 is exposed to water in a landfill, it is converted into hydrazoic acid, which is an extremely toxic, volatile liquid. Since most airbags will never be deployed and since each airbag contains between 50 and 150 grams of NaN3, concerns have been raised regarding the possibility of landfill pollution."
imartinez.etsin.upm.es/bk3/c15/Pyrotechnics.htm
madf
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