The 18-ton M4 high speed tractor series happens to be developed and built by the Allis-Chalmers production business of Milwaukee , Wisconsin , between 1943 and 1945. The design was based on the T9 and T9E1 had been standardized whilst the moderate Tractor M4 which became the High Speed Tractor M4.Together with the M5 and M6 High Speed Tractors they replaced the older commercial-type crawler tractors which couldn't meet the needs of a contemporary mechanized military anymore. The high speed tractors could carry both crew and a fundamental availability of ammunition. Production were only available in March 1943 and 5552 M4 tractors had been 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 created mainly as a prime mover for the 155mm gun? and 8-inch and 240mm howitzers.
