The front engine dragster came about due to engines initially being located in the car's frame in front of the driver. They did not use any form of suspension. Because of this, these types of vehicles were prone to becoming unstable at speed. This is due to their making, plus having poor tire technology, short wheelbases, and very lightweight. The driver sits angled backward, over the top of the differential in a cockpit situated between the two rear tires, a design originating with Mickey Thompson in 1954, as a way of improving traction. This position led to many drivers being maimed when catastrophic clutch failures occurred. Introduced with the start of organized drag racing, they were limited by the availability of traction from their rear tires or "slicks". A number of dragsters with four rear drive wheels were attempted as well, including cars by Art Chrisman, Bill Coburn, and Eddie Hill. Push starts were necessary until National Hot Rod Association mandated self-starters in 1976. After burnouts, cars would be pushed back by crews; this persisted until NHRA required reverse gears in 1980. The slingshot produced a number of fatal wrecks in the 1960s, including Mike Sorokin's and John Mulligan's. Clutches, bell housings, blowers, and engines exploded, with e.t.s hitting 6.43 seconds by the end of 1969, a pass recorded by Mulligan to qualify #1 at the Nationals. Other accidents included a flip by Jim Nicoll at the 1970 Nationals after a clutch failure. The slingshot's advantages, putting weight over the rear tires, now served to cause the front end to lift, as tire technology improved, to the point ballast, sometimes hundreds of pounds' worth, had to be added over the front axle, while others, like Ronnie Scrima and Tony Nancy, would mount a winglet. The drawbacks led to several attempts at rear-engined cars, but the rail was only supplanted by the rear-engined type when Don Garlits introduced Swamp Rat XIV in 1971. He designed the car while in hospital, having suffered from severe injuries caused by an exploding clutch.
