September 1959: First crash test at Mercedes-Benz
- The first Mercedes-Benz crash test was a head-on collision involving a test car and a stationary obstacle
- Ongoing development of testing procedures and test dummies
- Over 150 crash tests involving the E-Class from the 212 series
Although to begin with crash testing remained on a relatively small scale, from the 1960s onwards the procedure became increasingly established as a reliable instrument for optimising and testing vehicle safety. And at Mercedes-Benz thorough crash testing was applied not only to passenger cars, but also to vans, commercial vehicles and even coaches.
Crash testing at Mercedes-Benz has always exceeded the number and severity of the tests prescribed by law. In the case of the E-Class from the 212 series, for example, the programme that developed the saloon to production standard involved over 150 crash tests and over 17,000 realistic crash test simulations. These included a number of particularly severe crash tests conducted specifically by the company above and beyond the 40 or so different prescribed collision configurations required for the ratings and worldwide authorisation of a vehicle. Even the first crash tests in 1959 were characterised by these same high aspirations towards in-house development work.
Crash tests as the new instrument of safety research
Mercedes-Benz began taking a more rigorous approach to vehicle crashworthiness over 20 years before the first crash test. But although Mercedes-Benz engineers carried out the first tests on vehicles as far back as the 1930s, these were not for the purpose of research into passive safety. They served in fact to remedy the unwelcome effects of oscillating vibrations.
1939 was a key year in the history of safety at the Stuttgart brand, for this was the year Daimler-Benz AG signed up the engineer Béla Barényi. His developments were to prove definitive in terms of passive safety for the modern passenger car. Barényi’s inventions were described in over 2,500 patents and included the safety body with rigid passenger cell and front and rear crumple zones (premiered in 1959 in the W 111 series) and the safety steering wheel, which made its debut in 1976 in the 123 series.
Barényi and his colleagues developed the safety body to production standard in the 1950s, the crumple zones of which were designed to absorb the kinetic energy of a crash by controlled deformation. The prevailing view at this time was still that the interests of occupant safety were best served by maximum rigidity of the body. However, the new crash tests introduced in 1959 showed that although bodies such as these were good at withstanding impacts, most of the kinetic energy released was transmitted to the vehicle occupants and often led to serious injuries. Crumple zones, on the other hand, significantly reduced the amount of energy transmitted to the occupants in the event of an accident.
From individual measures to the concept of crashworthiness
The safety body patented in 1951 marked a decisive advance for passive safety. Barényi’s development was the result of precise observation, a great technical imagination and a capacity for visionary thinking. But many other aspects of the passenger car in addition to the body structure were improved and revised in terms of safety during this period. These included details such as the door locks, interior upholstery and padding, windscreens made from safety glass and seat belts.
During the 1950s the Daimler-Benz engineers watched closely to see how crash testing established itself as a new instrument of research and development in the United States. Visits to American universities and car manufacturers provided the experts from Stuttgart with inspiration and ideas for their own component testing and crash tests.
One such visit was made by Karl Wilfert, Rudolf Uhlenhaut and Fritz Nallinger to Ford’s crash testing facility in Dearborn in 1955. The men from Stuttgart were surprised to discover that Ford was already using accident research for aggressive marketing purposes at that time. This would soon influence the way Mercedes-Benz dealt with the sensitive issue of vehicle safety.
In addition, from the 1960s onwards representatives from Mercedes-Benz also began taking part in the Stapp Car Crash Conferences. One of the main contributions from Stuttgart in the early years was Karl Wilfert’s 1966 presentation entitled “Comprehensive Vehicle Safety Development.”
Preliminary component testing and accident simulation
The new W 111 series was the first to benefit from preliminary vehicle safety tests conducted by the engineers. Although there were as yet no crash tests in the precise sense of the term, the company’s own researchers had already begun testing individual vehicle components for their behaviour in accidents since 1956 and 1957. The inception of these tests represented a major watershed in the safety research of the Stuttgart brand. For until then the only information concerning passive vehicle safety had come from expert inspections of crash vehicles.
As far as component testing was concerned, the engineers focused initially on parts from the vehicle interior. In so doing they were able to apply existing methods used by the glazing industry, where a few years earlier a simulator had been developed to study the behaviour of safety glass; this was used to simulate the impact of a human head against the front windscreen.
Mercedes-Benz used a similar design of apparatus, for example, to test the padded surface of instrument panels: a spring fired a five-kilogram wooden ball at the component being tested, while a tracer registered the deceleration of the artificial head striking the padding. Gradually the engineers used the dummy head to test other components of the vehicle interior. Such tests showed the inherent dangers not only in protruding components, but also in wooden trim, which had a tendency to splinter. However, since many customers – in particular those buying luxury class models – preferred genuine wood as a material for interior equipment, Mercedes-Benz developed a multilayered composite material, in which the wood was prevented from splintering by aluminium inserts.
The development of the safety belt in the late 1950s also called for a reliable testing procedure for this new restraint system in vehicles. The solution developed in 1959 was the test sled, originally suspended so that it could be swung with acceleration against a fixed object. This initial model subsequently gave rise to the horizontal test sled on rails, which was accelerated using steel springs. The ‘guinea pig’ used was a dummy acquired in the United States. This early test dummy, also used in crash testing, was given the name Oskar by its guardians. As a mute pioneer of safety research at Mercedes-Benz, Oskar went on to spawn future generations of dummies. Indeed, the climate dummy, developed in 2007 to test for specific perception of vehicle temperatures, was named Dr. Oscar.
As well as the safety belt, the accident simulator was also used to test the padded steering wheel impact absorber and other such components. By the mid 1960s the first-generation sleds had given way to a new type of impact vehicle, to which a complete passenger car body could be attached for load testing if required.