The 18-ton M4 high speed tractor series happens to be developed and built by the Allis-Chalmers Manufacturing Company of Milwaukee , Wisconsin , between 1943 and 1945. The design had been in relation to the T9 and T9E1 was standardized while the moderate Tractor M4 which became the tall Speed Tractor M4.Together aided by the M5 and M6 tall Speed Tractors they replaced the older commercial-type crawler tractors which would not meet with the needs of a modern mechanized army any more. The high speed tractors could carry both crew and a basic way to obtain ammunition. Production started in March 1943 and 5552 M4 tractors were assembled until June 1945,plus 259 M 4A 1 tractors between June and August 1945. The 18-ton M4 high rate tractor ended up being designed primarily as a prime mover the 155mm gun? and 8-inch and 240mm howitzers.
