US troops after Japan’s surrender inspect Shinhoto Chi-Ha tanks retrofitted with 120mm naval short guns on Japanese home island of Honshu.
(See clearer close-up photo below)
Late in World War II, the Imperial Japanese Navy developed a Type97 Shinhoto (new turret) Chi-Ha Medium Tank variant by replacing its gun with a naval 12 cm (120 mm) short gun. Produced in small numbers and deployed by the Japanese Special Naval Landing Forces it is unclear if the gun tank ever saw combat. If it had, it would have proven to be a nasty surprise since the gun was orders of magnitude larger and more powerful than any other Japanese tank in the field, but wrapped in a familiar Chi-Ha hull.
How the gun in this tank would have performed against various ground targets is something military buffs can debate. Sources suggest that it was not very accurate and was meant to be used for a barrage effect. A handful of such tanks on a shore with Navy landing forces could effectively assault fortified positions with their massive shells or severely damage any enemy armor or vehicles that might get caught in the line of fire, but the gun was not meant for pinpoint accuracy. As such this could be called an “assault tank” and one suited for the sort of aggressive charges favored by the Japanese in battle.
Possibly in pursuit of more accuracy, a 120mm Long-Barreled Naval Gun Chi-Ha prototype version was also in development – photos of that tank show (below) it had no turret or casemate, at least during testing. That long gun variant needed a stable platform to fire or face tipping over. The short-barreled 120mm, by contrast, was capable of being housed in a long Shinhoto turret, though it is reasonable to expect that a gun designed for use on ships similarly would at least have rocked the tank when fired.
The Naval Long Gun 120mm Prototype in Testing
Also worth mentioning here is the similarity to the Army’s Type2 Ho-I tank, which held a smaller 75mm “mountain gun” and had a similar turret, but was built on the basis of the improved (rivet-less, welded armor) and heavier Chi-He.
As a matter of “shock and awe” wielded by the SNLF, this 120mm gun tank would have been an impressive force to reckon with if used to support landing troops or as an ambush tank suddenly emerging from the jungle.
Armament: The tank carried its shells internally. The “submarine gun” was originally designed off the 12cm/45 10th year type gun which was an AA gun which had been replaced by the Type89 12.7cm guns. It fired a fixed piece shell of 34kg in weight (75 lbs). The shell was 94cm in length.
Ammunition: The tank was designed to fire 2 types of HE shells, a base fuse with a soft flat cap designed to dive and hit submarines, and a nose fused shell with settings for time delay or impact fuse. It seems though that the US personnel found it armed with both types of shells, so it looks like the SNLF were going to attempt to use the anti-submarine shells for use against armored targets or bunkers. At the very least it is hard to imagine a U.S. tank taking a hit to its tracks (for example) without significant damage even from the soft flat cap 120mm shells.
Why include this tank in games?
1. It’s a 120mm Japanese gun tank – powerful and unique armament in a tank tree that does not have monsters like the Panzer VIII Maus.
2. The Naval theme is strong in this tank with a gun normally meant for warships. With one of Japan’s strengths and resource focuses being its Navy, this was an innovative approach and would add the right flavor to games that focus on the strengths of each nation.
It is difficult to find stock scale model examples of this tank, but one kit (in 1/72 scale) did/does exist, possibly from Armo: