Many Mercedes-Benz safety innovations, particularly in the field of protection for vehicle occupants and other road users, have saved countless human lives. In line with the "real-life safety" philosophy, findings from the company's in-house accident research are extensively incorporated into safety developments. Mercedes-Benz has long seen crash tests as a means of realistically reproducing what actually happens in accidents. To mark the opening of the technology centre for vehicle safety (TFS), Mercedes-Benz is displaying research and production vehicles from various eras. Also on display in the new crash hall are a Vito used by Mercedes-Benz accident research and a Tailfin Mercedes (W 111) with a hot-water rocket as a crash test combination.
Mercedes-Benz has been systematically conducting accident research since 1969, analysing and reconstructing serious road accidents in southern Germany in which Mercedes‑Benz models were involved. The work of the researchers usually begins at the accident scene: How did the accident come about? How were the vehicles positioned after the impact? Are there tyre or skid marks? How severely was the bodywork deformed? Were the belt tensioners and airbags deployed? Any number of questions, the answers to which are recorded in an exhaustive accident report. Plus dozens of photos, sketches and witness reports. The results are finally transferred to a database. The engineers are then able to use this to determine how frequently a particular type of accident occurs, for example. It also becomes possible to obtain a realistic picture of likely injuries and the probable course of accidents, producing findings for the development of new, even more effective protection systems.
First systematic crash tests
The first crash test in the history of Mercedes-Benz took place on 10 September 1959. Since then it is not only vehicle safety that has been developed further, but also the technology used during crash tests. A towing system was initially used to accelerate the test cars, for example, as they could not be accelerated under their own power. Things really got moving in 1962, when a hot-water rocket was first used to power the vehicles. This unit mounted on a single-axle trailer was attached to the rear of the test car, and consisted of a pressure tank, a fast-opening valve and a power nozzle. To produce thrust, the vessel was filled with water before the crash test and heated until the water reached a temperature of around 260 degrees Celsius. When the valve was opened, the resulting excess pressure propelled the vehicle and rocket forwards, and was able to accelerate the entire unit to more than 100 km/h.
Experimental safety vehicles (ESVs)
In the early 1970s Mercedes-Benz built over 30 experimental vehicles to research future automotive safety systems. These Experimental Safety Vehicles (ESVs/ESFs) prepared the way for numerous innovations, some of which it was only possible to incorporate into series production years later. They include ABS, the belt tensioner and belt force limiter, the airbag and side impact protection. ESF 22 (presented in 1973 in Kyoto/Japan) and ESF 24 (debut in 1974, London/Great Britain) were both based on the S-Class (W 116) and already equipped with ABS. Four three-point seat belts, each with three force limiters and a belt tensioner, were also on board. Another special feature in common was an extended front section with a hydraulic impact absorber.
ESF 2009 was the first modern experimental safety vehicle produced by Mercedes-Benz since 1974. Like its historic predecessors, it brings together pioneering innovations in the field of safety with intuitive accessibility, making progress come alive. It featured a total of 13 innovations, among them the beltbag (an inflatable belt strap, now in regular production), PRE-SAFE 360° (monitoring of the vehicle's surroundings to the rear as well, and precautionary locking of the brakes when a rear-end collision threatens; now in regular production) and partial high-beam headlamps (adaptive LED high beam automatically excludes oncoming traffic; now in regular production).
Protection of occupants and other road users in an accident
In the current smart fortwo (453 series) the successful basic safety concept of the preceding models has been retained: the tridion safety cell helps to protect the occupants. It consists of a high proportion of ultra high-strength, hot-formed steel and ultra high-strength multi-phase steel. In line with the Mercedes-Benz philosophy of "Real Life Safety", the focus for the Car2Car crash tests was also on compatibility with much larger and heavier vehicles. The smart fortwo meets high safety requirements, some of which go well beyond those prescribed by law. In summer 2014 this was demonstrated by an in-house offset crash test against a Mercedes-Benz S-Class (222 series): Although it was the smaller and lighter vehicle in the accident, where the impact speed was 50 km/h with a 50 percent overlap, the passenger cell of the smart remained intact with optimum occupant protection.
Comprehensive safety at the latest level: Intelligent technology is increasingly the main focus in accident research when it comes to early recognition of danger and the prevention of accidents. What began with the two Mercedes-Benz safety innovations ABS and ESP® has now found its current culmination in the new E-Class (213 series).
The driver is supported by numerous assistance systems that are able to enhance comfort and safety. With the help of numerous networked sensors (e.g. stereo camera, radar), and depending on the situation, the E-Class is able to recognise the risk of a collision with pedestrians and crossing traffic and initiate countermeasures. And in critical situations, as a precaution, the occupants are prepared for a possible impact by PRE-SAFE®. In the case of the latest innovation, PRE-SAFE® Impulse Side, it is now even possible to trigger a pyrotechnical system based on radar sensors just before a side impact. As accidents are also accompanied by noises to which some people have sensitive reactions, Mercedes-Benz has developed PRE-SAFE® Sound as a system which can prepare the human ear for impending accident noises by emitting a rushing sound.
Compared to the preceding model, the bodyshell of the Mercedes-Benz E-Class has a considerably higher proportion of components made from aluminium and ultra high-strength steel. The front wings, bonnet, boot lid/tailgate and large areas of the front and rear sections in the Saloon and Estate are made of aluminium panels or castings. As the first large-scale production model in this vehicle segment, the E-Class features major structural components such as parts of the rear side members made from diecast aluminium.