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Old 3rd January 2013, 05:19   #1
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Default How useful are Front Airbags?

I'd like to ask this question here since it relates to Indian cars most of which predominantly come with horrible equipment levels and very low safety kit with just two front airbags - one each for the driver and front passenger.

Common logic says these should work mainly in the case of head-on collisions, and even in that case a well-engineered bonnet should absorb most of the crash and seatbelts would ensure that the person doesn't even touch the airbag in the event of activation.

Despite the presence of front airbags, there is NO protection in situations like side collisions, pedals causing harm to legs, car upturning or rolling over (& consequent head injury), etc which somehow seem to happen often enough (compared to head-on collisions) to warrant concern.

So when is the Indian-class safety level (2 front airbags alone) useful ? Really severe head-on crash is all I can think of.

Could the BHPians shed some light in this regard ?

Last edited by MHG : 3rd January 2013 at 05:21.
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Old 3rd January 2013, 05:54   #2
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Default Re: How Useful are Front Airbags ?

I think you are oversimplifying the dynamics of a crash. Airbags are mandatory in western countries for a valid reason. In countries like the US auto manufacturers are very powerful in terms of lobbying to prevent anything unnecessary from being mandatory.

That said, I recommend watching a crash test videos of cars and the movement of the crash test dummy. The human neck is flexible and fragile, easy to break and cause death. Seat belt will hold on to the torso, but there is nothing stopping the neck and head from violently bending forward/breaking. Humans have a very heavy head. Human reflexes to stiffen the neck from flopping at crash speeds are non-existent. Unless you are Rajnikant who can dodge bullets

There are several such videos here.
http://www.youtube.com/user/firedemon101

Bonnet is designed to crumple and keep the cabin intact as much as possible, not to absorb all the kinetic energy at 60 or 80kmph. Coming to 0kmph from 80kmph may jiggle the neck free.

Last edited by prasadee : 3rd January 2013 at 05:57.
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Old 3rd January 2013, 06:06   #3
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Default Re: How Useful are Front Airbags ?

Quote:
Originally Posted by prasadee View Post
Bonnet is designed to crumple and keep the cabin intact as much as possible, not to absorb all the kinetic energy at 60 or 80kmph. Coming to 0kmph from 80kmph may jiggle the neck free.
Thanks for the post. Maybe the word "absorb" is ambiguous, but by that I meant the first line of your quote (crumpling and keeping cabin intact) itself.

PS: Now that I think of it, absorb might have been the wrong word. Excuse my English
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Old 3rd January 2013, 09:21   #4
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Default Re: How Useful are Front Airbags ?

I am not sure if a car can be designed for all the possible ways one may meet with an accident.

As more and more roads are being provided by a median, especially the highways, the possibility of head-on crashes and falling in ditches or hitting trees seem to be more likely.

There seems to be some side protection with protection bars being incorporated in the doors for some of the modern cars, that should protect possible intrusion from sideways.

Now safety like democracy seems to be measured in $$s, more $$s you have more safety you probably can afford! Micra offers only one airbag - for the driver! Some do offer airbags as an option.

A Nissan X-trail or probably the top version Aria offer upto 6 air bags (if I am not wrong) including side curtain airbags.

In any case the airbags are called SRS (supplementary restraining systems??) and are supposed to protect the head from moving forward and hitting the steering or moving forward to get snapped from the torso (morbid)?

Airbags are only effective if one is wearing seat belts. And the manuals say that you could suffer burn injuries possibly given that an air bag works as an inflatable device and is triggered by a micro-explosion! Ain't it funny that we carry a couple of micro-bombs in the car ready to explode!

I haven't had the misfortune of experiencing the working of airbags, but I can vouch for the seat belts working in a crash! And of course the crumple zone in the front working (though it cost me a bomb to repair it later). How I wished there was ABS option then!

More than the pedals hitting, often it is the steering that pokes into the driver's chest, in case of a head on collision or hit and we have today the option of collapsible steering systems.

I am happy to see that Indian cars are inching towards providing occupant safety options and discerning customers (and those who can afford) opting for some of these SRS, and safety options.

Depressingly, some of the manufacturers under the guise of value engineering offer only one mirror for those who think who can afford a car but not a mirror! That interestingly mirrors our general attitude towards safety! I think regulators should insist on two mirrors as a basic and compulsory feature, and also insist that people use them (I am not a votary for a 'nanny' state!)

To cut the chaff - do airbags work, I guess they do. But like many things these are 'luxuries' that those who value their life and limb can afford, and for the rest - Adristam (unseen force or a benign statistical process depending on whether you are a creationist or an evolved darwin inspired person) at work!
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Old 3rd January 2013, 09:24   #5
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Default Re: How Useful are Front Airbags ?

I think they are a must. They are a luxury only until (God forbid) you actually need them.

One point though, an airbag will not deploy unless the seat belt is being worn. Also, this silly and dangerous thing called the Bull Bar should not be there.
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Old 3rd January 2013, 09:39   #6
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Default Re: How Useful are Front Airbags ?

Airbags are always classified as SRS;
that is S upplementary R estraint S ystems.
The safety zones designed when a car is being designed are part of the B-I-W (Body - In - White); such as, side member design, bonnet breakaway points, bonnet hinge collapse points, pedal box rigidity and intrusion calculation, A-pillar rigidity, side sill load transfer paths etc , etc. Safety belts are "bought - off - the - shelf" items hence strictly speaking is not a "designed" part of the car.

In a particularly severe frontal collision, the "active" safety sytems absorb the bulk of the impacting forces. What filters through , or the secondary forces / residual impact is taken up the airbags. Airbags only "cushion" you in a severe frontal impact, causes your head to rest on a pillow of air instead of any hard protruding surface/plastic trim etc that may cause potential injury to your head.
Airbags alone will not save you in an accident. It has to be supplemented by the use of safety belts and all the inbuilt safety features of the vehicle. That is why in most cars , front airbags will not even deploy if you are not wearing the front safety belts. So in a nutshell, airbags are important, yes, they may not be necessary in very low speed driving environments (golf carts etc) but is definitely a safety supplement in daily city / highway driving conditions
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Old 3rd January 2013, 10:01   #7
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Default Re: How Useful are Front Airbags ?

The key thing one has to realize here is that Seat Belts are the single most important safety feature in a car. Air bags are a unique concept, but as pointed previously in this thread, their role is supplementary - to prevent serious injury to head and neck region (the front air bags i.e.)

The second most important safety feature would be the vehicle structure itself - i.e. adequate crumple zones. A simple corollary to this - No formula 1 or for that matter any serious track race car has an airbag and the focus there is mainly on crumple zones (on car and on track) to save the driver even in case of severe high speed crashes.

Current research on car safety is though very rightly focussed on preventing the occurence of the accident itself. Hence the Euro NCAP organization has greatly emphasized on active safety features like ESP and preventive braking, etc. Driver Drowsiness prevention is minor holy grail for researchers in automobile safety.

Driver-less or autopilot assisted cars are now a realm of real possibility and not science fiction and one is likely to see a greatly reduced incidence of automobile related accidents over the coming 2-3 decades - and by greatly reduced I would say by factors of many hundreds.

Such technological innovations are unfortunately difficult to readily implement in India (think lane change warnings, etc and the eventual autopilot car) due to horrible road infrastructure that currently exists and merely half hearted attempts at making safety a critical component of new highways.

Though statistics are difficult to come by - but purely based on empirical observations, most serious accidental injuries and deaths on Indian highways can be blamed on the deadly quad of:

1) No Seatbelt/Helmet usage
2) Drunk/sleepy driver
3) Random road obstacles (erratically moving or stalled vehicles, suddenly appearing pedestrains/animals, barely visible highway construction equipment)
4) Tyre Bursts

If you look at the 4 above, one gets the feeling that a determined adminstration (and by that I really imply a determined public, because the admin and elected reps are nothing but what we the people put forward) can really drastically prevent accident deaths and injuries.

~It always depresses me no end every time I think of road safety in India. Its a loosing battle and its just getting worse.
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Old 3rd January 2013, 10:15   #8
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Default Re: How Useful are Front Airbags ?

Slightly OT here! In a country where a significant portion of the cars are being chauffeur driven, the front airbags alone would not be sufficient measure except for self driven cars. Car makers should realise this and provide airbags for rear passengers as well and that could motivate more owners to go variants with these safety options.
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Old 3rd January 2013, 10:17   #9
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Default Re: How Useful are Front Airbags ?

Quote:
Originally Posted by MHG View Post
So when is the Indian-class safety level (2 front airbags alone) useful ? Really severe head-on crash is all I can think of.
Useful? Definitely YES.
You may like to go through EuroNCAP site and check out crash tests for cars with just 2 front airbags and see how they performed in the test.

e.g. Fiat Punto - 2000 make
http://www.euroncap.com/tests/fiat_punto_2000/28.aspx

Quote:
Despite the presence of front airbags, there is NO protection in situations like side collisions, pedals causing harm to legs, car upturning or rolling over (& consequent head injury), etc which somehow seem to happen often enough (compared to head-on collisions) to warrant concern.
A tank is what we need to save us from some of these and 'etc's"

On similar lines, everyone wants manufacturer to make safety features standard across variants. I would say why not people wait until they can afford to pay extra for the safety features available only in top variant? Or go for a smaller or segment lower car with all safety features rather then going in for a big or 'brand worthy' car with no safety features?

See the problem is not 'car makers' alone, its with the buyers too!
e.g. If 'X' car with all safety features costs 'Y' amount and then you have a segment higher 'Z' car with no ABS/AirBags and that too costs 'Y' amount then people go for the 'Z' car!!

I have seen this in real life hence thought of bringing it here!

Last edited by HammerHead : 3rd January 2013 at 10:29.
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Old 3rd January 2013, 11:30   #10
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Default Re: How Useful are Front Airbags ?

Front airbags are useful, but not as useful as -

1) Seatbelts
2) ABS

Seatbelts alone can help reduce injuries to passengers significantly. Meanwhile, ABS can help avoid accidents altogether. Like some wise man said, "Prevention is better than Cure".

I'd stay away from cars that were not originally intended to be equipped with airbags, but are now have them in top end models. Eg: Scorpio, Xylo, Safari. That's because airbags need to be activated at the right time based on the intensity of the collision and the ability of the chassis/body to absorb that impact. Just adding airbags without doing proper crash testing analysis will do no good. It's probably safer to buy non-airbag equipped Scorpio/Xylo/Safari.
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Old 3rd January 2013, 12:06   #11
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Default Re: How Useful are Front Airbags ?

Quote:
Originally Posted by sgiitk View Post
I think they are a must. They are a luxury only until (God forbid) you actually need them.

One point though, an airbag will not deploy unless the seat belt is being worn. Also, this silly and dangerous thing called the Bull Bar should not be there.
Sir,
AFAIK, wearing of seat belts is not a condition for air bags to deploy. IIRC airbags will deploy anyhow in a frontal collision, another function of the seat belt is that it tries to prevent/reduce the impact of the collision of the fastly deploying airbag with the front passenger, which if not prevented can itself cause serious injury because airbags expand at the rate of knots in case of a frontal collision.

Last edited by abhinavinc : 3rd January 2013 at 12:08.
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Old 3rd January 2013, 14:02   #12
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Default Re: How Useful are Front Airbags ?

Quote:
Originally Posted by abhinavinc View Post
Sir,
AFAIK, wearing of seat belts is not a condition for air bags to deploy. IIRC airbags will deploy anyhow in a frontal collision, another function of the seat belt is that it tries to prevent/reduce the impact of the collision of the fastly deploying airbag with the front passenger, which if not prevented can itself cause serious injury because airbags expand at the rate of knots in case of a frontal collision.
My information is Bag deployment is conditional on both the seat being occupied and also the belt being in use. I have read this stated emphatically on this or the other major forum. Someone was involved in an accident and the bag did not deploy, which was attributed to the belt not being worn.
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Old 3rd January 2013, 17:17   #13
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Default Re: How Useful are Front Airbags ?

Quote:
Originally Posted by abhinavinc View Post
Sir,
AFAIK, wearing of seat belts is not a condition for air bags to deploy. IIRC airbags will deploy anyhow in a frontal collision, another function of the seat belt is that it tries to prevent/reduce the impact of the collision of the fastly deploying airbag with the front passenger, which if not prevented can itself cause serious injury because airbags expand at the rate of knots in case of a frontal collision.
Airbags deployed in case of a collision when the passenger is not wearing a seat belt will do more harm than good. The airbag deployed when the passenger is not wearing a seat belt can potentially kill the passenger. The airbag deploys at the rate of 400mts/sec on an average and its fully deployed under 0.4s. At the same time, the passenger without wearing a seatbelt would be moving forward, the airbags pushing him backward with that great speed can kill him instantly. For the same reason, some manufacturers are developing variable speed while deploying an airbags which helps best in case of low speed crahes and more importantly the airbags wont deploy when the passenger is not wearing his seat belt.

Quote:
Originally Posted by MHG View Post

Could the BHPians shed some light in this regard ?
No car or vehicle has 100% safety record. As mentioned by one of our BHPians in the earlier post, everything comes at a price, even safety. The curtain airbags, front airbags or anything work based on a scenario. The frontal collision being the most probable scenario in an accident, the front airbags have been made mandatory in most countries except India (for obvious reasons)

Those who are ready to pay those extra $$$ for safety in most scenarios get them and its not like all the airbags would work in every scenario and put you in an airball to safety. The curtain airbags or side airbags or central airbags all come at a cost and they work ONLY when the sensors picks up the required signals to satisfy that scenario to deploy airbags.

The front airbags is still a worthy basic safety feature in cars. I would pay that extra money to have one in my car!
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Old 3rd January 2013, 17:45   #14
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Default Re: How Useful are Front Airbags ?

Quote:
Originally Posted by anachronix View Post
The frontal collision being the most probable scenario in an accident, the front airbags have been made mandatory in most countries except India (for obvious reasons)
Is it ? Don't many lethal accidents involve head injuries due to sideways impact ? Isn't a curtain airbag as critical as a front airbag ?
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Old 3rd January 2013, 17:56   #15
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Default Re: How Useful are Front Airbags ?

I hope you got what I meant when I said the frontal collision being the most probable, it doesnt make the other scenarios as improbable.

Lethal accidents happen in any form, like the most recent Figo accident where the complete roof portion of the car was chopped off under the truck. I am talking about the probability here, the mandatory regulations usually go after these probabilities and work on mitigations.

Just look around, you will find the reasons how mandatory regulations are setup for cars.

Quote:
Originally Posted by MHG View Post
Is it ? Don't many lethal accidents involve head injuries due to sideways impact ? Isn't a curtain airbag as critical as a front airbag ?
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