STB-1 '69

In 1962, shortly after accepting the Type 61 into service, Japan began to design a new main battle tank that would better repel such vehicles as the Soviet T-62. The first prototype, dubbed the STB-1, incorporated features from other tanks contemporarily being developed, including the MBT-70’s hydropneumatic suspension and the Leopard 1’s 105mm L7 rifled gun. The STB-1 entered testing in 1969 and was developed further to become the Type 74.