[vina]

Originally Posted by suhaas307

That is true, but assuming you're doing 60 and you're 3 seconds away from hitting the rear of a truck. You brake really hard, the sensors activate and 'know' that there is an impact waiting to happen, and just when the car senses the impact, the airbags will deploy, and in the case of the S, the safety equipment ensures that windows (sunroof) and doors are closed in order to prevent flying objects and debris from entering the car and hurting the occupants.

Electronics ready the airbag, yes. But right before impact, when the car begins to decelerate very quickly, the sensors engage the airbags to deploy at time of impact.

And the brakes of a car are only as good as the driver. If you're 3-seconds away from hitting something while doing considerable speed, well, you just gotta say your prayers.

Well, I'm not trying to be rude here, but your interpretation of the article and other info regarding airbags is just wrong.

Airbags are activated the second vehicle starts moving (in some vehicle front airbags after vehicle is moving with some speed - side airbags the second you turn the ignition ...).

The only thing the "imminent collision" systems do is position the occupants in more optimal location - tighten the seatbelts, move the seats ... they do not mess with airbags.

There are systems (radar based) that lower the front of the car in case they detect an imminent head-on collision at very high speeds - that causes at least some of the kinetic energy of the car to convert into rotational energy (on impact the rear will rise very high) rather than crumple the front.


The airbag sensors and deployment system works so fast, and has to be so reliable that usually between sensor and the explosive charge there is just a wire. And sensors are always at their most sensitive - there is no pre-sensitising or anything you can do.

[suhaas307]

Originally Posted by vina

Airbags are activated the second vehicle starts moving (in some vehicle front airbags after vehicle is moving with some speed - side airbags the second you turn the ignition ...).

The only thing the "imminent collision" systems do is position the occupants in more optimal location - tighten the seatbelts, move the seats ... they do not mess with airbags.

There are systems (radar based) that lower the front of the car in case they detect an imminent head-on collision at very high speeds - that causes at least some of the kinetic energy of the car to convert into rotational energy (on impact the rear will rise very high) rather than crumple the front.


The airbag sensors and deployment system works so fast, and has to be so reliable that usually between sensor and the explosive charge there is just a wire. And sensors are always at their most sensitive - there is no pre-sensitising or anything you can do.

Thank you Vina.

I'd read about this in a reputed automobile-magazine years ago, and even went through some of the threads here on Team BHP, but I couldn't quite remember it correctly. Thanks for pointing it out again. EDIT: And just for the record, I wasn't really claiming to be correct again. Was everything I said completely wrong?

[DieselFan]

Originally Posted by suhaas307

That is true, but assuming you're doing 60 and you're 3 seconds away from hitting the rear of a truck. You brake really hard, the sensors activate and 'know' that there is an impact waiting to happen, and just when the car senses the impact, the airbags will deploy, and in the case of the S, the safety equipment ensures that windows (sunroof) and doors are closed in order to prevent flying objects and debris from entering the car and hurting the occupants.

Electronics ready the airbag, yes. But right before impact, when the car begins to decelerate very quickly, the sensors engage the airbags to deploy at time of impact.

And the brakes of a car are only as good as the driver. If you're 3-seconds away from hitting something while doing considerable speed, well, you just gotta say your prayers.

This information is all wrong. When the crash test is carried out on cars using dummies, there is no de-acceleration of the car. Car is accelerated to attain a speed of 35MPH and the car crashes into a solid wall. Airbags do inflate don't they?

[vina]

Originally Posted by suhaas307

...EDIT: And just for the record, I wasn't really claiming to be correct again. Was everything I said completely wrong?

Well. some part of the interpretation was wrong, some was correct. If you read my post you can see which one is correct and which one isn't.

By the way, IMHO and AFAIK of all the studies done - front airbags are practically useless if seatbelts do what they are supposed to do. With proper fastening to the seats, the occupants' body shouldn't move much, in the absence of front airbags the body wouldn't hit anything with any excessive force, if at all (if airbags are deployed they should hit the airbags).

There are very few comparative studies done of safety with seatbelt only vs. seatbelt+airbag (I found only one on the internet) AFAIK. I would love to be corrected on this if anybody has some real technical information.

Of course the question then is whether people will allow seatbelts to their work (intentionally or unintentionally putting them on the wrong way, not putting them at all ...)

[Warhound]

Another incident of a Mercedes Head on collision with no Air bag deployed. ( Jan 3, 2012)

ट�रक में घ�सी मर�सिडीज, �क ही �अर बैग ख�ला, �क की मौत <br>

My hindi reading skills are elementary so please for others on this forum as well translate.

[Tapish]

Here's an image of the latest accident.

The car hit straight on the A pillar.



This seems more a problem of the trucks than Mercs.

Tapish

[vikram_d]

Originally Posted by Warhound

Another incident of a Mercedes Head on collision with no Air bag deployed. ( Jan 3, 2012)

ट�रक में घ�सी मर�सिडीज, �क ही �अर बैग ख�ला, �क की मौत <br>

My hindi reading skills are elementary so please for others on this forum as well translate.

The title of the story itself says that one airbag deployed and one person died. The title roughly translates as "Mercedes crashes into a truck, only one airbag deployed, one person dead.
The title of the article posted by Tapish is pure sensationalization. It reads "Mercedes airbag betrays again". I find title this title so hilarious. No airbag in the world would have saved anybody in such a crash.

In such an accident, even an airbag cannot save anybody. Look at the condition of the car. I'm sure on this impact most of the electrical stuff would have malfunctioned. I agree with Tapish, this is more a problem with trucks than with Mercs. Where is the crash protection guard the truck is supposed to have to prevent vehicles from going under it.

[nanduchitnis]

What ever but the Air bag should have deployed in this accident !

[vikram_d]

Originally Posted by nanduchitnis

What ever but the Air bag should have deployed in this accident !

Would the airbag deploying have saved the person?

[carwatcher]

What I feel after reading about Airbags is that come on there can't be a single technological feature possible which will cover all kind of situations ever. We have technological failures or I would call them limitations with everything be it Mobiles, computers, and what not. Even Seatbelts can't guarantee safety in ALL the situations. Shifting the blame entirely on technology is utterly immature. Why do we still have no ATs which can be better then MTs even though so many years have passed. I see the insatiable hunger for continuous technological advanced products is responsble for that. Or else how can justify the launches of 4 upgrades of mobile phones in 2-3 years.
Its human tendency to sensationalize matters. First they will shout from the roof to claim Mercs and BMWs and german cars are extremely safe, then they will again go on the roof and shout Merc takes youth's life. No one is bothered to look at the facts. Latest trend going is of NCAP safety ratings. The safety ratings are given for certain variants of certain models with certain features. But Auto mags and manufacturers present the product in such a way as though all variants in that car are 5-star certified.

[tbppjpr]

I searched a-lot but couldn't find any "Euro NCAP Crash Test" video of S-Class, not even could find safety ratings from same institution for the mentioned car . Could someone please help me to find out? Or its not a rated car?

In both the accidents cars directly got hit on A-Pillars, so moral of the story is never bang to a truck or something higher than bonnet, otherwise all the safety features will turn out useless.

[vb-saan]

Originally Posted by tbppjpr

I searched a-lot but couldn't find any "Euro NCAP Crash Test" video of S-Class, not even could find safety ratings from same institution for the mentioned car. Could someone please help me to find out? Or its not a rated car?

Good point. Even though it comes with an array of safety features, the S-Class is not listed Euro NCAP website (Mercedes Benz | Euro NCAP - For safer cars crash test safety rating)

And some of the international websites have also mentioned that the S-Class is not NCAP rated.
Mercedes-Benz S-Class saloon review | CarBuyer
Mercedes-Benz S 300 L (A) 2010 Specifications | New Cars | Oneshift.com

[drmohitg]

In such an accident wouldn't the Airbag get deflated even if it deployed in the first place? Or are they made of some different material which is puncture proof?

BTW I am saddened that the paper choose to ignore the basis of the accident. Why was the merc travelling at those speeds?

[mayankk]

Originally Posted by drmohitg

In such an accident wouldn't the Airbag get deflated even if it deployed in the first place? Or are they made of some different material which is puncture proof?

BTW I am saddened that the paper choose to ignore the basis of the accident. Why was the merc travelling at those speeds?

I recall from a merc safety video that airbags aint sealed.
They have vents and deflate quite immediately.
perhaps someone has seen a deflated one recently, and can say?

[vikram_d]

Airbags do have tiny holes in them. They start deflating as soon as they have inflated completely. Different materials are used by different airbag manufacturers. Some use a porous material which lets the gas escape and some use non-porous materials with holes in them. The net effect of both type of materials is the same. They will start to deflate as soon as they have inflated completely.