You Never Notice It, Until One Goes Off In Your Face... 40 Years Of The Mercedes Driver Airbag

You Never Notice It, Until One Goes Off In Your Face… 40 Years Of The Mercedes Driver Airbag

Over 40 years ago Mercedes Benz introduced the driver airbag in series production. In the 1980 Over 40 years ago Mercedes Benz introduced the driver airbag in series production. From the end of 1980 for the W126 S-Class, the airbag became an optional extra and was delivered to the first customers in 1981. Developed jointly with Bosch, this was the start of what has now become a standard product.

But it wasn’t just an airbag, you see Mercedes had coupled it with a seatbelt tensioner. Previewed back in December 1980 it went into production in the following January. The W126 that was the first car to have the new technology, setting another passive safety milestone.

The World premier was at the Amsterdam international Motor Show in February 1981. Then one month later at the Geneva Motor Show. Available for the S-Class and SEC Coupés as an option and costing DM 1,525.50.

Over 40 years ago Mercedes Benz introduced the driver airbag in series production. From the end of 1980 for the W126 S-Class, the airbag became an optional extra and was delivered to the first customers in 1981. Developed jointly with Bosch, this was the start of what has now become a standard product.

But it wasn’t just an airbag, you see Mercedes had coupled it with a seatbelt tensioner. Previewed back in December 1980 it went into production in the following January. The W126 that was the first car to have the new technology, setting another passive safety milestone.

The World premier was at the Amsterdam international Motor Show in February 1981. Then one month later at the Geneva Motor Show. Available for the S-Class and SEC Coupés as an option and costing DM 1,525.50.

In the first two months more than 100 of the S-Class vehicles were fitted with one. This new safety system was very quickly adopted by other manufacturers across the world.

As soon as 1982 Mercedes were able to offer this across the whole model range and from 1992 it was a standard fitment. By 1994 a passenger airbag was also standard equipment. Since then, airbags have been appearing all over the cabin, turning the average car interior into a bouncy castle in the event of an accident. But they work.

An airbag is deployed with a propellant within only milliseconds in front of the vehicle occupants. Sensors in the vehicle detect strong deceleration. So, the sudden braking in a severe head-on collision triggers the firing of a propellant charge. This propellant mixture was mainly nitrogen at the start. It inflated a cushion shaped fabric bag. Combined with a seat belt it offers the best possible protection. Both airbag and seatbelt tensioner combined work to gently cushion the upper body when thrown forward by the impact.

In the first two months more than 100 of the S-Class vehicles were fitted with one. This new safety system was very quickly adopted by other manufacturers across the world.

As soon as 1982 Mercedes were able to offer this across the whole model range and from 1992 it was a standard fitment. By 1994 a passenger airbag was also standard equipment. Since then, airbags have been appearing all over the cabin, turning the average car interior into a bouncy castle in the event of an accident. But they work.

An airbag is deployed with a propellant within only milliseconds in front of the vehicle occupants. Sensors in the vehicle detect strong deceleration. So, the sudden braking in a severe head-on collision triggers the firing of a propellant charge. This propellant mixture was mainly nitrogen at the start. It inflated a cushion shaped fabric bag. Combined with a seat belt it offers the best possible protection. Both airbag and seatbelt tensioner combined work to gently cushion the upper body when thrown forward by the impact.

Mercedes-Benz Airbag Patent

The Airbag Development

The concept for the airbag can be attributed to hobby inventor, Walter Linderer amongst others. He had the idea of an “inflatable container in a folded state, which automatically inflates in the event of danger”.

On the 6 October 1951, the inventor from Munich filed to protect his “device to protect persons in vehicles against injury in the event of collisions” with the German Patent Office. Even though the patent described the principles of the airbag some technical requirements didn’t exist. The sensors weren’t available, and neither was a propellant for rapid gas generation. Compressed air simply wasn’t suitable as it takes far too long. There wasn’t even an elastic and tear resistant material for the bag itself.  

While these issues remained, Mercedes-Benz started to develop the idea in back in 1966. Initial trials took place for the gas propellant in 1967 and they were able to file their patent. In October 1971 the application for “Impact protection device for vehicle occupants” (Patent No: DE 21 52 902 C2) was filed by Daimler-Benz AG.

Mercedes-Benz Airbag Patent
You Never Notice It, Until One Goes Off In Your Face… 40 Years Of The Mercedes Driver Airbag

More than 250 crash tests, over more than 2,500 sled tests and thousands of component tests were performed over a fifteen year period. Mercedes-Benz managed to bring the air bag to production.

SRS airbag was the abbreviation applied to the steering wheel to let you know it was fitted behind the horn push. The Supplemental Restraint System didn’t just mean the air bag, it came as a pair with the seat belt tensioner. In effect supplementing that as it is the primary restraint system after all.

Those original air bags were pretty large having a volume of between 60 and 70 litres. So, the centre of the wheel grew in bulk to suit.

Not quite as bad as the passenger air bag. The first presentation of that at the International Motor Show in Frankfurt back in 1987, it filled the entire glove box.

You Never Notice It, Until One Goes Off In Your Face… 40 Years Of The Mercedes Driver Airbag
Sequence showing the functioning of steering-wheel airbag and seat belt tensioner in 1981.

Seatbelt Tensioner Parallel Development

In parallel Mercedes were working on the seatbelt tensioner. This reacts to the same sensor signals as the airbag. Another propellant charge is fired to tighten the seats three point belt. This is to eliminate the slack in the belt between the driver’s body and the seatbelt. This works on both passenger and driver holding them firmly in the seat.

Further innovation continued with the addition of belt force limiters in 1995. Should stop some of the bruising… The alternatives are far worse.
 
In 2002 the engineers added an electronic element to the seat belt tensioner. PRE-SAFE was a resettable system, unlike the pyrotechnic one, where there is an initial tensioning before the charge is fired. If there is no collision the system loosens the belt again. Clever stuff when you think about it.
Mercedes-Benz S-Class SRS System
S-Class Airbag Deployment

It’s a well-known fact that seatbelts and airbags are known to save lives. It is hard however to measure these with any meaningful statistics. Whilst they don’t prevent accidents, they only work when you’ve had one.

The German Federal Statistical Office statistics may help. In 1980, 15,050 people were killed on German roads (in both East and West Germany back then). Some 6,915 of them were occupants of passenger cars.
 
In 2000, the same figures had fallen to 7,503 and 4,396. Nearly 20 years later in 2019, on German roads there were 3,046 road traffic victims in 2019. 1,346 died in a passenger car.
 
Now, as the numbers of cars on the roads has risen quite a bit since then it makes the the rate of reduction impressive. When measured as traffic deaths per 10,000 vehicles you can really see the impact. What was 4.5 in 1980 dropped to 1.4 in 2000 and again to 0.5 in 2019.
 
Kind of speaks for itself, doesn’t it?

Many thanks to Mercedes-Benz AG for the use of the images. 

Simon

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