Please wait a moment ...
Please wait a moment ...
Airbag and belt tensioner included as standard
- In 1981, the Mercedes-Benz S-Class was the world’s first car with airbag and belt tensioner
- Optional equipment initially, an inherent part of an integrated safety package today
In July 1981, the Mercedes-Benz S-Class from the W 126 series was launched with new optional equipment when the airbag and the belt tensioner – as many as two passive safety innovations at one time – became world firsts in the top-of-the-range models of the Stutt-gart-based manufacturer. From July 1981, the combination of driver airbag and front-passenger belt tensioner was exclusively available for the sedans and coupes from the 126 series at a price of 1,525.50 DM (roughly 780 euros).
In that year, as many as 2,636 S-Class buyers opted for the new safety equipment, setting the airbag on its triumphant march around the world. During the first 25 years after the launch of the new technology, over twelve million vehicles from Mercedes-Benz were equipped with airbags, and other brands followed suit. The optional equipment item for the driver of 1981 has developed into a restraint system which today incorporates airbags, belt tensioners and belt force limiters to protect the occupants in an accident.
Airbag in the impact absorber
The incorporation of this safety item in standard-production cars had been preceded by many years of research and development work. In 1971, Daimler-Benz had been granted patent no. DE 2152902 C2 for the airbag. However, the restraint system still had to be improved in many detail features and thoroughly tested before reaching maturity for large-scale production. In more than 250 accident tests with complete cars, over 2,500 sled tests and thousands of tests on individual components, the airbag had to prove its reliable functioning. At the same time, long-term tests with 600 cars were carried out on and off the road to establish that the airbag was not inadvertently triggered in normal operation.
In 1992, the driver airbag was included in the standard equipment of all Mercedes-Benz models, followed by the front-passenger airbag in 1994. In continuous further development, the airbag module became ever smaller while at the same time affording ever more comprehensive protection. As early as 1993, Mercedes-Benz presented a study of a side airbag – a feature which was made optionally available for the E-Class in 1995. The window bag was included in the standard specifications – initially of the S-Class – in 1998. And for the roadsters of the Mercedes-Benz SL-Class, the head-thorax side airbag was introduced in 2001.
In the S-Class from the W 221 series, adaptive airbags form part of the PRO-SAFE™ safety philosophy: the airbags are triggered in two different stages depending on the severity of the accident and the occupant’s weight. Future generations of the airbag will adjust even more effectively to the individual occupants onboard a car. In a next step, the Mercedes-Benz development engineers are testing the integration of the airbag in the PRE-SAFE® preventive protection system. This will ensure that airbags are not triggered as late as during a collision but as early as immediately before the accident in order to cushion and restrain the occupants.
From pyrotechnical belt tensioner to PRE-SAFE®
The belt tensioner presented together with the airbag also established itself as an element of passive safety. The system was introduced in Geneva in 1981. In an accident, the support system triggered a pyrotechnical charge and pulled the inertia-reel three-point seat belt on the front passenger’s seat tight in just a few milliseconds. In this way, the safety equipment in the S-Class from the W 126 series reliably secured the front passenger in his or her seat, even when the belt had been fastened with too much slack before.
From 1984, all Mercedes-Benz models were fitted with belt tensioners on the front seats as standard. In 1995, the belt tensioners in all models were combined with belt force limiters in order to adjust the performance of the restraint system to individual requirements. In 2002, the pyrotechnical belt tensioner was complemented by an electronic belt tensioner within the framework of the introduction of the PRE-SAFE® preventive occupant protection system. This electronic unit pulls the seat belts tight when PRE-SAFE® identifies a critical situation and prepares the car for an imminent crash. Unlike the pyrotechnical belt tensioner, the electronic unit is reversible – the belt is loosened again when a collision can be avoided.