During 1930s, fears were strong among the most powerful military nations that a coming war would develop along the same lines as WWI. No one wanted another war rife with stalemates, no one moving for months on end due to swamp like terrain, and constant machine gun bombardment. As such, tank designs of the period were heavily set on infantry support, being large, slow moving and bristling with anti-personal weaponry. The era became awash with the fad of multi-turret tank designs, with all of the most powerful countries adopting them in one form or the other.
The A1E1 Independent for the British Empire, the Großtraktor or Neubaufahrzeug for Nazi Germany, and the T-35 of the Soviet Union are prime examples of this design fashion. One might even consider the mobile machine-gun nest that was the United States’ M2 Medium to be part of the group.
Imperial Japan was no exception to the rule, coming up with their own design in 1934. This was the Type 95 Heavy Tank (タイプ95重タンク, Taipu 95-jū tanku).
The Experimental Tank No. 1, Type 87 Chi-I.
The roots of the Type 95 Heavy begin with the first tank the Japanese Military produced independently, the Experimental Tank No.1 (実験タンク番号壱, Jikken tanku bangō wən), also known as the Type 87 Chi-I. This ancestor to all Japanese tanks was built in 1927, and was classed by the Military as a Medium Tank. It didn’t progress further than the prototype phase, however.
The Type 91
The first prototype of this heavy tank was built in 1931 and was designated the Type 91. This was an 18-ton vehicle, powered by a 6-cylinder BMW IV inline engine that ran on gasoline. The engine was likely purchased from Germany. The tank had 3 turrets, a main one in the center armed with a 57 mm (2.24 in) cannon, and 2 secondary forward and rear turrets armed with 6.5 mm (0.26 in) machine guns. It also had an armor 8 – 17 mm thick.
The Prototype vehicle Type 91, undergoing crossing trials. The complicated suspension can be seen here.
A feature carried over from the Type 87 Chi-I was the rather complicated parallelogram suspension system with two pairs of road wheels per leaf-sprung bogie. There were 17 road wheels per side, giving it a total of 34 road wheels. The parallelogram type of suspension is more commonly known as Swing arm suspension, which is mostly used on motorcycles.
The Type 91 proved to be an unsuccessful endeavor, and the project was soon canceled. The lessons learned were passed on to the Type 95.
Type 95 Heavy, Design and Development
Imperial Japan felt that the increasingly powerful Soviet Union could be a potential future enemy. As such, work once more resumed on a heavy tank for the Imperial Japanese Army (IJA) to match the Red Army’s T-35 heavy tank.
The development of the Type 95 Heavy began in 1932, with a prototype not being complete until 1934. The overall structure of the chassis and module layout was much the same as the previous Type 91 prototype. However, it was given significantly thicker armor, thicker than all of Japan’s other tanks of the era. The turret face was 30 mm, with 25 mm on the sides and the rear. The upper plate bore the thickest armor at 35 mm. The sides weren’t lacking either as they were 30mm thick with a further 25mm on the rear of the vehicle.
This amount of armor increased the weight of the vehicle to 26 tons, the heaviest tank Japan had yet built.
The suspension was also altered, with a much simpler form of leaf-spring suspension. The amount of road wheels was drastically reduced, down to 9 a side, giving it a total of 18. This was found to give the same performance, while being much less complicated.
The Type 95 during trials, showing how the suspension operates.