Episode 4: Systematic protection.
Continuous research in the interest of safety is tradition at Mercedes-Benz. Following milestones of passive and active safety, the focus these days is on integral safety that comprises all systems.
Premiere of the airbag.
A big bang of vehicle safety took place in the late 1960s: at that time, an airbag with propellant inflated in the laboratories of Mercedes-Benz Research for the first time. The life-saving airbag celebrated its world premiere together with belt tensioners for driver and front passenger in the S-Class in 1981.
Today, we are surrounded by airbags all throughout car: in the front, at the windows and the interior sides. In the S-Class and E-Class, airbag components are now even integrated into the rear seat belts: the beltbag inflates pyrotechnically and as a result more than doubles the width of the belt.
It was a long journey to this success, a journey on which the engineers also explored unusual avenues. For example, in the 1960s and 1970s, some of them attended an “officially recognised special blasting training course for airbag technicians” that included a final exam to be licensed to experiment with propellants. It paid off: the charges actually proved to be an excellent method to inflate the airbag in the blink of an eye when the electronic sensors detect an accident.
Systematic protection: the side view of the passenger cell of the Mercedes-Benz E-Class Saloon (W 213) shows numerous restraint systems.
They include safety belts with pyrotechnical belt tensioning in the front and on the outer rear seats, reversible electric PRE-SAFE® belt tensioners in the front, driver airbag and kneebag, front-passenger airbag, window airbags, front and rear side airbags (optional in the rear), beltbags in the rear on the outer seats (optional) and PRE-SAFE® Impulse for the front seats (optional).
Focus on the entire vehicle.
The safety belt is still the primary restraint device. The airbag complements it to decelerate the body over a large contact area. The many other active safety assistance systems supplement its effect and as a result, the human occupant is protected comprehensively.
Ever since Mercedes-Benz started to conduct intensive safety research, the focus has always been on the entire vehicle. Béla Barényi also examined the typical car body shell from this perspective. The engineer started working at Mercedes-Benz in 1939. During his life, he filed more than 2500 patent applications and is considered the pioneer of modern vehicle safety.
Left: Patent on the crumple zone: in 1951, Béla Barényi filed a patent application for the safety body.
Right: Shaft for safety: the new safety steering shaft was patented by Béla Barényi in 1963.
Patent on the crumple zone.
Barényi invented the concept of the safety body with front and rear crumple zones book-ending a rigid passenger cell. It was an ingenious concept: in an accident, the front and rear structures deform in a controlled manner and dissipate kinetic energy in the process. The rigid cell in the vehicle centre on the other hand protects the passengers. The concept works so well that it is used by all vehicle manufacturers today.
Crash tests since 1959.
Of course, Barényi filed a patent for the ingenious idea of the safety body – and he did so in 1951. The concept became a reality in that same decade:
it celebrated its production premiere in the Mercedes-Benz 'Fintail' saloon cars in August 1959. How well the whole thing worked became clear just a few weeks later when the first crash test was conducted at Mercedes-Benz in 1959.
The first dummy.
During such realistic crash tests, the sensors installed in the dummies record the forces that would act on a human in an accident. The first dummy used by Mercedes-Benz was actually given a name: he was called Oskar. Since then, many of these crash test dummies, which year after year take quite a beating in the service of safety, have been added.
After all, more than 100 crash tests are conducted before a new Mercedes-Benz goes into production. In addition, there are also countless digital simulations. They allow the engineers to compute the vehicle’s crash behaviour as early as the development phase. And this involves not only the metal structure, but also items such as the steering system.
Another result of the rigorous research into vehicle safety was the safety steering shaft, likewise a pioneering Barényi patent: the steering shaft is designed as a collapsible tube and in accident yields in several directions to prevent it from intruding into the interior. The entire concept was used for the first time in Mercedes-Benz model series 123 in 1976 – a predecessor of the E-Class. It was part of the solutions for passive safety.
Technology for exemplary protection.
Further milestones of safety included the anti-lock braking system ABS (1978) and the Electronic Stability Program ESP® (1995) – both count as active safety systems. The convertibles and roadsters from Mercedes-Benz also benefited from the rigorous safety development.
For example, the SL of model series 129 became the world's first two-seater with a pop-up roll-over bar in 1989. The first four-seat convertible with a corresponding protection system celebrated its world premiere in the model series 124 in 1991.
And today? Vehicles from Mercedes-Benz adhere to the concept of integral safety that combines both worlds to the best advantage. This also includes the PRE-SAFE® solutions, which activate preventive accident protection measures.