The Hellcat was originally designed by Buick in 1943. Unlike most other self-propelled guns, the M18 was built on a specially designed chassis, not on top of a standard tank chassis.
The M18 enjoyed another technical innovation: its engine was set on special rails for easy removal. Its disadvantages included an open tower, which made the crew vulnerable to mortars, artillery, and infantry. This narrowed its combat effectiveness, while recommending it for use in ambush. The troops who operated M18 Hellcat Tank Destroyers celebrated it widely for its convenience of operation and maintenance, and its reliability.
Over its serial production 2,500 units were manufactured.
Secondary: 12.7mm M2HB