In 1942, Japan began to cooperate more closely with Germany in tank construction. Emphasis was placed on hull welding technology, optics, and other aspects in which Japanese technology lagged behind. In the same year, the project of the Type 3 heavy breakout tank appeared. The vehicle resembled a larger medium tank with improved armor and armament. Auxiliary machine gun turrets were abandoned. The project was designed with cast turrets and Hara-type suspension, but with staggered support rollers and a liquid-cooled aircraft engine. Development stopped at the design stage.