The seventies gave birth to the idea of producing the safest car possible. At all the major manufacturers, heaps and heaps of resources were poured into creating a car where safety was priority number one. These prototypes were the early predecessors to the modern day safety incubators which transport people from A to B. One of the biggest challenges back then, was that all the focus on safety led to those concepts looking quite horrific and suffering massive weight gains.
But it was a necessity. The cars produced up through the fifties and sixties were generally becoming faster and faster. At the same time, traffic density was increasing in every major city around the globe. Yet focus on passenger safety remained largely stagnant. The results were starting to get noticed by both governments, press and the public.
As the world entered the 1970s, the American car dream was about to meet its demise – or at the very least, severe changes. The highly potent and fuel munching muscle cars only had a few more good years. Right around the corner, they were faced with new federal rules regarding emissions (which would lead to high octane fuel being taken off the shelf), increasing fuel prices and blanket speed restrictions all coming into force with the 1973 oil crisis. All of this further boosted the idea of creating safer cars and the Department of Transport (DOT) came up with an ambitious project called ESV – or Experimental Safety Vehicle.
The goal was quite simply a future with safer cars which would save the lives of hundreds of thousands of drivers and passengers. The death toll on US roads had increased by 30% up through the 60s. DOT initiated a widespread research and analysis, and subsequently came up with a dogma which car manufacturers were requested to follow. It was a list of no less than 82 points which all strived to make cars safer, and thereby turn around the frightening statistics which accompanied accidents which resulted in death. ESV – as the dogma was named – quickly gained a strong political backing and soon enough evolved into legislation on the US market. Needless to say, all American manufacturers were thereby forced to adhere to the new legislation, but it obviously affected European and Japanese manufacturers too. The US-market was too big to ignore. Both the European and the Japanese needed to be present on the US market if they were to make a profit. So despite ESV being initiated in the USA, every car manufacturer in the world had to at least attempt to meet this new legislation.
The list included both small and major suggestions. Among the easily achieved were requirements such as warning lights on the dashboard which would light up if a brake light had failed, or door mirrors which were adjustable from within the cabin. However, one of the more challenging was the requirement for collisions up to 10 mph without damaging the bumpers of body of a car, which Claus recently wrote a stand-alone article about right here. As we know, the US-market cars from the mid 70s are often characterised by these enormous bumpers the size of picnic tables. The bumpers along with all these other safety requirements resulted in a vast weight increase for all cars, which in turn meant that there was now a need for more powerful engines. But the oil crisis had arrived and improved fuel consumption was just as big a topic as was safety. The two really didn’t go hand in hand very well.
Even before the 70’s, Mercedes-Benz had already established a leading role within automotive safety, and thus invested heavily in the new ESV as soon as it was launched – ESF was their German acronym. The German luxury car manufacturer built 35 different safety vehicles, the first of which were based on their compact W114 model. Compared to the ordinary production version, their ESF 05 was a staggering 600 kg. heavier and was equipped with gigantic rubber bumpers. Furthermore, it had a net in the rear window to protect rear seat passengers in a collision, an automatic seatbelt for the driver, four airbags and an early incarnation of ABS brakes.
The wheelbase of the ESF 05 was increased by 100mm to compensate to the space taken up by the two rear seat airbags which were installed in the seatback of the front seats. The straight-6 engine was swapped for a V6 to free up space for the crumble zone built into the front of the car, and inside the cabin they experimented with a soft, foamed dashboard and doorcards to further absorb energy. The headlights were adjustable and had their own wipers, and both the windscreen and the rear screen were made from laminated glass. With a curbweight of 2060 kg. the compact Mercedes-Benz was no featherweight.
The equipment list of the ESF 05 was impressive and the car was presented in 1971 at the second international conference for ESV. But despite the efforts of the German engineers, a test committee found the cars safety levels to be unsatisfactory.
Only six months later, Mercedes-Benz tried again with their new ESF 13 during the third ESV conference in Washington in 1972. It was largely an identical car to the ESF 05 in terms of safety, but this time the whole concept had been aesthetically enhanced so as to make the car a more realistic commercial prospect too. Particular focus had been given to the bumpers which were now somewhat more elegant, and functioned as an integral part of the cars deformation zone which was to absorb as much energy as possible and lead it under the car in the event of a collision. The ESF 13 weighed in at 2100 kg. – a not insignificant 705 kg. more than the ordinary production car upon which it was based.
Then in 1973, for the fourth ESV conference in Kyoto, Mercedes-Benz presented their ESF 22. This was inherently a more modern construction as it was based on the newer W116 S-class. Once again, the overall design was improved much and was aesthetically very close indeed to that of the original production car. However this was achieved through compromise. The ESF 22 could no longer withstand a frontal collision at 50 mph, but only 40 mph.
But it’s interesting to note that the difference in weight between the ordinary production W116 and the ESF 22 was now reduced to a much more reasonable 287 kg. A significant advance in the integration of safety equipment for Mercedes-Benz! Yet the reduced abilities of the ESF 22 during a frontal collision clearly did not please the ESV committee, who again found Mercedes-Benz’s efforts unsatisfactory. Mercedes-Benz reacted by subsequently not following DOT’s suggestions 100%, but instead continuing their safety development program according to their own criteria.
Once again based on the W116, the new ESF 24 was presented in 1974 during the fifth ESV conference, this time in London. It also proved to be the final Mercedes-Benz in the ESF program. By now they had obtained sufficient skill and knowledge to incorporate the same safety level as with the ESF 22, but in the ESF 24 there were no aesthetical differences from the normal production car. The ESF 24 was thus ready to by marketed and the weight gain was now below 200 kg. Mercedes-Benz felt they no longer had anything to prove when it came to the ESV program as a vast list of elements had been fully implemented. On the S-class, you now got well-engineered deformation zones, reinforced seats, automatic seatbelts and much more. ABS brakes was even an option.
Even though we here at ViaRETRO mostly talk about beauty, handling characteristics, performance and rarity, a much less sexy subject such as development is certainly justified too. When it comes to old cars, safety is really a bit of a taboo, as classics rarely have much to offer here. We can only hope that this will not come to affect our continued use of classic cars out on public roads. That said, I’m sure we can all agree that the huge leaps which have been achieved in both active and passive safety in modern cars is obviously a good thing.