The front-engine dragster is a type of racing car purposely built for drag racing. Commonly known as a "rail", "digger", or "slingshot", it is now considered obsolete, and is used only in nostalgia drag racing. Wheelbases ranged from . History The front-engine dragster was an evolution from earlier front-engine hot rods and initially was a car from which all non-essential parts, including the body, had been removed to reduce weight, making the earliest dragsters essentially a production car chassis with a "souped-up" engine. These early dragsters were nicknamed "rails," due to the frame's longitudinal members (rails) being exposed to view. As the dragster design further evolved, the rear suspension was eliminated to reduce weight and enhance traction. More development resulted as builders started fabricating custom frames optimized for drag racing, with driver crash protection being integral to the frame. With the transition from stripped-down production frames to purpose-built ones, the engine was moved rearward so more of its weight would be on the rear (driving) wheels for increased traction. Rearward positioning of the engine meant the driver had to be moved rearward as well, and in the final version of the front-engine dragster, the driver was positioned behind the rear axle at the very rear of the car. The arrangement of rearward engine mounting and the driver being behind the rear axle gave rise to the colloquial name "slingshot." Mickey Thompson is credited with introducing the slingshot design in 1954; it would become the dominate dragster design until the early 1970s. In the quest to develop more driving traction, there were several dragsters built with four rear drive wheels, including cars by Art Chrisman (along with his brother, Lloyd, and partner Frank Cannon), Bill Coburn, and Eddie Hill. (Coburn and the Chrisman brothers used twin engines, also.). None of these four-wheel designs bore fruit; the development of tires designed specifically for drag racing made four wheels unnecessary. In keeping with the austere nature of a dragster, the heavy cranking motor and battery needed to start the engine were two of the items removed to save weight, requiring that the dragster be push-started. This procedure was necessary until 1976, when the National Hot Rod Association (NHRA) mandated that all cars be capable of being started without pushing. As many dragsters had no reverse gear—indeed, many had no transmission at all—cars would have to be pushed back by crews after a burnout;