Chrysler tank arsenal. Individual mobile arsenals are the outpost of the huge Chrysler tank arsenal on the outskirts of Detroit. A worker is here installing a machine gun on an M-3 tank, one of the twenty-eight ton giants which mount four machine guns, two .50 calibre and two .30 calibre, a .75 mm. gun and a 37 mm. anti-aircraft gun, as well as an assortment of hand machine guns, and other weapons for use by the crew