Comparing: AT 8 vs. M18 Hellcat

The vehicle was conceived as a breakthrough tank. The design project evolved from the AT-7 project, and both projects were submitted at the same time. No prototypes were built because the A39 Tortoise was preferred.

Development started in 1942. In April 1943 the General Motors company produced the first prototypes. One of a few American tank destroyers manufactured on its original chassis, not on a tank chassis. The tank destroyer became the fastest armored vehicle, of this type, of World War II. A total of 2,507 vehicles were produced from July 1943 through October 1944.