Stuttgart. On 23 January 1951, Daimler-Benz AG registered a patent for the passenger car body with a passenger safety cell. This invention by Béla Barényi was granted Patent No. 845 157 with the title “Motor vehicle, specifically for personal transport”. This was a trailblazing innovation, as it is still seen as the fundamental feature of passive automotive safety to this day. In 1959 the safety body with its rigid passenger cell entered series production for the first time in the Mercedes-Benz W 111 series (model 220b). Together with numerous other developments, the passenger safety cell patented in 1951 is one of the technical standards that Mercedes-Benz continues to set worldwide for improvements in passive automotive safety.

With this development based on his earlier prototypes and patents, the Daimler-Benz engineer and “safety pioneer” Barényi finally parted company with a hallowed principle of vehicle construction that had been valid for decades: designers previously thought that a body that was as rigid as possible was the best way to protect the driver and passengers in an accident. In fact it means that the forces generated during the impact are transferred to the occupants with hardly any prior absorption. For this reason Barényi turned to controlled body deformation at the front and rear, so as to absorb the kinetic energy built up during a collision. At the same time a rigid passenger safety cell in the middle of the vehicle enclosed the occupants and protected them from the impact forces acting on the vehicle structure.

The overall vehicle concept therefore consisted of three cells: the safety cell in the middle and cells at the front and rear which were flexibly connected to it. The text of the patent application explains the purpose of this design as follows: “The forces generated during a collision are […] absorbed by the [front or rear] cell section.” Later on a catchy expression was coined for these areas of controlled deformation: they entered the language as “crumple-zones”.

Born in Austria-Hungary in 1907, Barényi entered employment at Daimler-Benz as an engineer in 1939. Initially he worked under the management of Karl Wilfert, on an experimental vehicle with an innovative floor assembly known as a “platform frame”. The Second World War interrupted Barényi’s research on solutions for improved passive safety. After the war he first worked as a self-employed engineer, and it was in this time that the “Terracruiser” and “Concadoro” studies were created that predated the later cellular body principle: both studies had a structurally very strong passenger cell in the middle, to which deformable crash cells at the front and rear were flexibly connected.

In 1948 he was reemployed by Daimler-Benz AG, and in the following months he turned many of his designs into new patents. Patent No. 845 157 registered in 1951 was particularly seminal. The development of the passenger safety cell at
Mercedes-Benz also increased the awareness of developers where automotive safety in general was concerned. In the W 111 series (model 220b) presented in 1959, Barényi therefore not only realised his visionary safety body, but also introduced a new safety steering wheel that featured a large impact plate and a deformable connecting piece between the plate and the end of the steering column, which was moved forward.

In 1959 Daimler-Benz AG also started to carry out systematic crash tests with Mercedes-Benz saloon cars – the first of these tests was a frontal collision by a W 111-series car against a rigid barrier on 10 September 1959. The data obtained during these tests helped to ensure that the modern automobile with the safety body invented by Barényi became increasingly safe.

All in all Barényi patented around 2500 of his developments, most of them in the field of vehicle safety. In recognition of this achievement, Barényi was adopted into the “Automotive Hall of Fame” in 1994. The principles formulated by the “father of passive safety” in the mid-20th Century are also followed by today’s developments at Mercedes-Benz. In all of these, the safety body with its rigid passenger cell perfectly complements the numerous new solutions developed for passive and active vehicle safety.