May 30, 2011

Developing the death-proof car.

As a result of rising death rates in auto crashes, the U.S. Department of Transportation launched the Experimental Safety Vehicle program in 1970. The program was intended as a way for various automakers to learn more about both passive and active safety in cars and apply that knowledge to production cars in the next ten or so years.

It consisted of building prototypes that met certain requirements: they had to keep passengers alive in a 50mph crash into a solid barrier, withstand side impacts at 30mph, protect the car’s occupants in a 75mph rear end collision, and survive two complete rollovers at 60-70mph.

Some of the guidelines revolved around handling so manufacturers couldn’t simply turn an economy sedan into an armored tank that destroyed everything in its way. The prototypes had to stop from 60mph within 155 feet on a dry road, accelerate from 30 to 70mph in less than 12 seconds with a 60% load and make an abrupt 180 degree turn at 70mph without rolling over.

The test cars were organized by weight classes: 1500 pounds, 2000 pounds, 2500 pounds and 4000 pounds. Part of the guidelines was, of course, that the cars actually respect the weight limit in each class, something most of the participating manufacturers had a hard time doing given the extra equipment they bolted on to each car.

These prototypes were remarkable in both the effort and resources put forth to develop and build them but also in the far-fetched ideas that some manufacturers came up with in order to supposedly make a car safer. Popular Mechanics hit the nail on the head when in June of 1972 they observed that “the world may never want to place an ESV in production, but we sure want the answers the cars can give us.”

We picked a few ESV prototypes to take a look at but it’s far from an exhaustive list. Looking at all of them would take ages; lots of manufacturers took part in the program including Opel, Renault, GM and Nissan.

American Machine & Foundry AMF 2

AMF has manufactured a vast variety of products: bicycles, tennis rackets, golf clubs, snowmobiles and even Harley Davidson motorcycles, just to name a few. Conspicuously absent from that list are cars, but they gave the ESV program a shot anyways. Their prototype was part of the 4000 pound category but weighed a whopping 5,791 pounds. It had a steel body with aluminum bumpers that had a thirty inch (!) travel. Rear visibility was assured by a submarine-like periscope, visible on the roof.

Like many other ESV prototypes it had airbags to protect the occupants and AMF took it further by adding automatic fire extinguishers. It is remembered as one of the best ESVs built by an American company.

Fiat ESV 1500

Fiat’s ESV for the 1500 pound category was one of the three the company built in the early 1970s. The other two were in the 2000 pound and 2500 pound category, respectively.

To develop the 1500 pound ESV Fiat used crash test data from the 500. The prototype uses a 500 running gear with a slightly bigger engine to counter the added weight, though the use of 126 parts is noticeable as well. This one met most DOT requirements for its weight class including fire protection, safe driving in foggy weather and pedestrian safety. The requirement it didn’t meet was the weight – it weighed a little over 1700 pounds in a weight class limited to 1500 pounds.

Ford ESV

Unlike a lot of other ESVs Ford’s prototype was based entirely on an existing production car, the LTD. Compared to the car found on dealer lots, the LTD ESV had a longer hood and a shorter trunk. Like the AMF above it was part of the 4000 pound category and also like the AMF, it weighed considerably more: the Ford tipped the scales at almost 5,300 pounds.

Compared to a stock LTD the brakes and suspension were modified to comply with the DOT’s handling requirements, including the addition of an ABS system that acted only on two wheels. The bumpers were hydraulically retractable to withstand a 10mph crash.

Both Ford and GM charged the government $1 for the development of their ESVs.

Honda ESV

Honda’s ESV was not an ESV in the true sense of the term. Instead they tried to build a mass-produced car to ESV standards, the same path that Ford followed. Ford did much better than Honda but they were starting with a bigger and heavier car; Honda was starting with a Civic. Honda strengthened the Civic’s body all around, including the door pillars to increase protection in a rollover. The engine was the same 55hp unit found in the production car.

Because of miscellaneous setbacks revolving around the Civic’s tiny size, the prototype took a year longer to complete than the other ESVs.

Mercedes-Benz ESF 22

Mercedes was very active in the ESV program: the ESF 22 was their third prototype after the ESF 5 in September of 1971 and the ESF 13 in 1972. First two prototypes were based on a w114 250 sedan but the ESF 22 was based on the w116 450 SE.

The ESF 22 used ABS brakes all around and experimented with airbags. Although the ESF 22’s long hood kept occupants alive even in the event of a 40mph crash against a solid structure, Mercedes’ prototypes did not comply with all of the DOT-mandated requirements in the program. Mercedes built a fourth and final one, the ESF 24, and called it quits.


This was another small car entry. MG started with a B GT body and added equipment such as a heads up display for the speedometer, airbags, big rubber bumpers and a self leveling suspension that would be later outlawed by DOT.

MG drunk driver-proofed the car by having a little colorful sequence show up on a screen when the key was inserted. Before the car would start, the driver would have to reproduce the sequence. The driver had three tries; if by the third the correct sequence had not been entered, the car would be impossible to start for an hour. The idea was that if someone was drunk enough, they wouldn’t be able to reproduce the sequence in the right order.

One of the few features from the SSV 1 to make it on a production MG are the huge rubber bumpers, though certain MG owners have reported seeing a sequence of flashing lights on the dash followed by their car not starting.

Toyota ESV

Toyota took a smaller approach to the ESV prototype: they developed a 2500 pound two-seater coupe. It was powered by a 1700cc mated to an automatic transmission, seen as safer than a manual transmission since it was run by a computer and not a human.

The prototype was packed full of electronics, including a system that adjusted the brightness of the headlight based on the car’s speed. The car also had radars to scope out the road ahead for obstacles. If one was found too close and the radar judged that a collision was unavoidable, it would send a signal to deploy the “gasbags”. The car also used what Toyota called failure warning board, a sort of on-board computer that monitored brake fluid level, engine oil level, etc.

Volkswagen ESVW-I

Staying true to Volkswagen tradition, their ESV had a 1700cc rear-mounted air-cooled engine. It developed 100 hp and was fully compliant with U.S. emissions.

Interestingly enough Volkswagen opted not to use airbags. Instead, they had seatbelts that automatically restrained passengers in the event of a crash thanks to gas-fired pistons. The car was equipped with what Volkswagen called a “silent co-pilot” system that calculated how much crosswind was hitting the car and from what side and electronically compensated the steering for it.

On the outside the bumpers didn’t stick out near as much as other prototypes and period Volkswagen literature bragged that their ESV had a “nearly normal” appearance, as opposed to other cars in the program.

Volkswagen built a second ESV in 1974, the ESVW – II, based on a first generation Golf/Rabbit. They exited the program soon after because they realized that the safety features would be too costly to implement in a production car.

Volvo VESC

Volvo has always been a leader in auto safety so it shouldn’t come as a surprise that they started developing the VESC in 1969, a full year before the DOT started the ESV program. With that said it was not developed with any of the program guidelines in mind but excelled anyways. It weighed a few pounds shy of 3,200 pounds.

The bumper had a seven inch travel distance to absorb shock and the engine was designed to get pushed under the floor in the event of a front collision, something Mercedes introduced on their W168 A-Class in 1997. To effectively stop the car ABS was fitted on all four wheels. On the inside, occupants were protected by both front and rear airbags.

No comments: