Heavy tank which bounces even "Ro-Ta-Ho". Shower of heavy artillery shell... Although infantry anti tank weapons are useful, they are not good at offence or distant holding action. Now we introduce a "big guy" who can break through such situations.
It is not secret that Japanese army lacked good anti tank equipments. They not only fold their arms but struggled. The development of 47mm new turret Chi-ha and a series of 75mm gun tanks enabled resistance against M4 Sherman tanks. It was clear that their enemy will bring new "shield".
In 1944, Japanese intelligence service detected American new heavy tank project. The project was known as"M1 heavy tank". It has 150mm frontal armor and 76mm side armor, and the gun was bigger than 3 inch. Although it was confused M26 with M6, that was urgent threat for Japanese army. And Russian heavy tank's information was also brought from Germany. A countermeasure against these new heavy tanks was life and death issue and powerful anti-tank firepower was required.
There were another requisition for powerful self-propelled firepower.
In every age, army requires more firepower and mobility, which brings firepower to battlefield. Also Japanese army developed motorized artillery like Type 90 field gun and Type 96 howitzer. It is clear that supreme artillery is motorizing artillery itself, a self-propelled artillery.
Self-propelled artillery have two major advantages. First, improvement of artillery mobility bring firepower rapidly. However powerful the firepower is, it can't fight if the gun was not in battlefield. Higher mobility means bigger chance to join a battle.
The second advantage is survivability. Firing gun makes loud sound and glaring flash. By observing these appearance, artillery positions can be detected. Once these positions was detected, enemy tries all method to destroy artillery, like counter-battery, air support and even special forces.
Japanese army knows well these two points by both doctrine and action. At a case of failure, they got counter-battery from all guns of a American corps artillery for only three guns. As successful example, they won a mobile anti-tank fighting in Philippines by using mountain gun which mounted on truck.
The demand of powerful anti-tank firepower and requisition of motorized artillery, these two motives made this vehicle. Type 5 Enperimental self-propelled Gun "Ho-Chi". This vehicle is not well known, but it is clear that the project was started in 1944 and the production scheduled in next year.
It uses Type 97 medium tank's hull. Type 97 tank was already out of date in these days and main production was shifted to Type 3 medium tank. So Ho-Chi's hull must be not newly produced but surplus one, like Type 4 "Ho-Ro". Because Type 97 tanks were out of date in these days, this selection was reasonable.
This vehicle was fixed turret style, which is similar to other Japanese self-propelled artillery. Because open top style is weak against air burst artillery, Ho-Chi had armored ceiling. Back of superstructure is opened for reloading and gun operating. The armor thickness is assumed same as Chi-ha.
Its armament was Type 96 15cm howitzer, which sometimes lacks mobility because of own weight. But this gun was a bit too big for little Type 97 tank. So the recoiling length, traverse range and elevation angle were reduced. Its firepower is same as Type 96 Howitzer, so it has bigger blasting radius. In anti-tank use, because Type 96 was a bit short as 15 cm class gun, its penetration capability is not legendary. But its heavier shell makes internal armor flaking effect. This gun can use also 4th year type 15 cm howitzer's shell, including H.E.A.T. shell which can penetrate 150mm armor.