Milestone in Mercedes-Benz safety development with solutions for
active and passive safety such as ABS and airbags
The number 13 was a real lucky number for vehicle safety 50 years ago: Mercedes-Benz presented the Experimental Safety Vehicle, ESF 13 for short, at the “Transpo 72” trade fair in Washington D.C. on 31 May 1972. It was ahead of its time with solutions such as the anti-lock brake system ABS, airbags for all passengers, a headlamp system with halogen light and also parallel wipers for the rear window.
The ESF 13 was part of a comprehensive programme of Mercedes-Benz safety development in the 1970s, which saw the creation of more than 30 such vehicle safety innovators. From this unique history, the Mercedes-Benz Museum is showing the ESF 22 from 1973, which is on display in the Legend Room 5: Visionaries – Safety and Environment, 1960 to 1982. Mercedes-Benz has also continued the ESF programme in the recent past: most recently, the ESF 2009 and ESF 2019 premiered in their respective calendar years.
Today, vehicle safety is once again making revolutionary progress. The brand with the star is once again a pioneer in the development of new solutions for the future. This is because part of Mercedes-Benz’s transformation towards sustainable mobility with alternative drives, digitalisation and connected and automated driving includes appropriate safety concepts. These range from innovative solutions for active and passive safety to high-voltage safety concepts for electric vehicles. The experts are also conducting research into possible accident scenarios in future mixed traffic with automated cars. One thing connects past, present and future: the motivation to develop the best possible safety systems for personal mobility.
Public premiere at “Transpo 72”
The “Transpo 72”, an international trade fair for mobility, was held in the capital of the United States of America from 27 May to 4 June 1972. The German research vehicle for improving vehicle safety was a highlight of the “3rd International Safety Vehicle Conference” (3rd International ESF Conference) incorporated into the event from 30 May to 2 June 1972.
A public exhibition of twelve ESFs from European, Japanese and US manufacturers accompanied the safety conference. This show gave around one million visitors from all over the world “a striking glimpse into the future of safer driving and vehicle safety”, as the 1972 conference report puts it. The report also underlines the claim that the highly focused development of the ESF for vehicle safety would bring “a ‘quantum jump’ over the customary year-by-year, step-by-step evolution in the auto industry”.
Innovation carrier based on the “Stroke-Eight” and SL
The ESF 13 was a further development of the ESF 05, which Mercedes-Benz presented at the 2nd International ESF Conference in Sindelfingen on 26 October 1971. Once again, a Mercedes-Benz 250 “Stroke-Eight” (W 114) served as the basis, and the engineers also used parts from the 350 SL sports car (R 107) for the ESF 13. Even visually, the somewhat futuristic-looking Experimental Safety Vehicle already stood out clearly from the successful upper mid-range saloon. Technically, the differences were even more obvious as the list of active and passive safety solutions integrated in the ESF 13 was long. All in all, the solutions for condition, operation and perception safety in the ESF 13 reflect the state of the art in Daimler-Benz safety research in 1972.
In addition to ABS, the halogen headlamp system, the wash-wipe systems for the headlamps and windscreen and also the parallel wiper for the rear window, the engineers presented numerous other solutions. To further improve passive safety for vehicle occupants and also pedestrians, various components were clad with foamed components or were compliant. There were three-point safety belts with belt force limiters on the front seats that fastened automatically when the door was closed. The safety steering wheel with impact absorber was supplemented by driver and front passenger airbags, as well as airbags for the rear passengers. In the rear, there were also three-point safety belts with belt force limiters and inertia reels. While the driver and front passenger seats had head restraints, this task was taken over in the rear by a new type of safety net. The ESF 13 thus saw the premiere of many technologies that later found their way into series production. For example, the ABS anti-lock brake system became standard in the S-Class of the 116 series in 1978, and the driver’s airbag with belt tensioner for the front passenger followed in the S-Class of the 126 series in 1981.
Profile: The Mercedes-Benz ESF 13
- Restraint systems and other details as for the ESF 05
- Designed for impact speeds of up to 80 km/h
- Five 3-point belts, each equipped with three force limiters, self-fastening belts in the front
- Driver and front passenger airbags, with a supplementary airbag in the backrest of each front seat designed to protect rear passengers in the outer seats
- V6 test engine to gain deformation space at the front
- Impact areas in the interior padded with polyurethane foam, especially doors, pillars and roof frame
- Power windows instead of rotary crank handles in the doors
- Lamp wiper, headlamp range control, rear window parallel wiper
- Side marker lights, tail lights with standstill relay and control device
- Laminated glass front and rear windows, bonded
- Pedals with rounded lower part
- Brake system with ABS anti-lock brake system
- Overall length 5,235 millimetres (550 millimetres more than the standard series vehicle)
- Front-end extension including hydraulic impact absorber: 420 millimetres
- Bumpers arranged so that they are accessible from underneath
- Kerb weight: 2,100 kilogrammes (705 kilogrammes more than the standard series vehicle)