Type: medium tank.
Crew: 4 men.
Armament: a Type 90 57 mm gun:a Type 97 7.7 mm machine gun at the rear of the turret; a Type 97 7.7 mm machine gun at the front
Armour:
minimum 8 mm;
maximum 25mm.
Dimensions:
length: 5.51 m;
width: 2.33m;
height: 2.23 m.
Weight in combat order: 15 t.
Engine: Mitsubishi 12 cyl. air-cooled diesel, developing 172 hp at 2,000 rpm.
Performance:
road speed: 38 km/h;
range: 210 km;
vertical obstacle: 0.81 m;
clean cut 2.51 m;
slope: 57%.
Service time: in the Japanese army from 1938 to 1945. Also used by China after the Second World War.
The CHI-HA was the standard tank of the Japanese armies throughout the Second World War. Entered into service shortly before Pearl Harbour, it was to equip the armored units intended for subsequent conquests. But neither the state of the Japanese armaments industry, nor the priority requirements of the naval air war, nor the chronic shortage of raw materials, nor especially the tactical conceptions of the Imperial General Staff favored its development. The general staff remained steadfastly faithful to traditional concepts far removed from the blitzkrieg war waged by armored forces such as had been experienced in the European theatre. The Japanese armored forces were never engaged in accordance with a modern employment doctrine.
The technical evolution of the CHI-HA presents analogies with that of the M.13 throughout the campaign of Italy. In both cases, a basic cell was used to produce successive versions in armament and shielding.
Type 97 CHI-HA tanks were engaged in all sectors of operations from the Pacific, Far Eastern and Manchurian theaters. They often operated there in very small formations, or served as casemates on fixed positions.
By the mid-1930s, Japanese operations on Chinese territory had highlighted the need to withdraw the Type 89 medium tank, dating from 1929, from service, despite several attempts at modernization. It was proposed to replace it with a new model of a medium tank, weighing 15 tons, capable of reaching a speed of 35 km/h. Possessing good offensive and defensive capabilities, this tank was to form the backbone of large Japanese armored units.
On the other hand, the pressing need was felt for an armored vehicle be lighter but able to be produced very quickly. The Japanese authorities therefore decided to have two prototypes made, the heaviest by Mitsubishi Heavy Industries, according to the specifications of the technical services, the Osaka arsenal being responsible for the lighter one, which was favored by certain members of the Imperial General Staff.
Both models received the type designation 97, their definition dating from 1937, and the respective names of Chi-Ha and Chi-Ni.
The Chi-Ni appeared first. It weighed 9.8 tons and was 5.26 m long. With a crew of three men, it reached a speed of 35 km/h and crossed trenches 2.5 m wide. Its engine, an air-cooled six-cylinder Mitsubishi diesel developed a power of 135 HP. It was armed with a 57 mm Type 90 gun paired with a 6.5 mm Type 91 machine gun.
The armor had a fairly good profile and maneuverability was satisfactory in all terrain. The crew could monitor the engine without having to go out into the open. Particular attention was paid to the suspension, made up of horizontal coil springs acting on four pendulums attached to four bogies with two rollers on each side. The track was supported by three carrying rollers in the upper part of its travel, and its tension was regulated by the position of a deflection pulley.
But the single-seat turret was a weak point for a battle tank, and for crossing the 2.50 m ditch, the Chi-Ni had to use a "tail" inspired by the Renault.
The Chi-Ha prototype made a better impression. It had an additional machine gun, and a more powerful engine (170 horsepower) which, despite its mass (13.5 t), gave this tank a maximum speed superiority of 8 km/h. Its turret was two-seater and the crew had been increased to four men.
There were bitter discussions about whether to order one or the other model,
but the day of July 7, 1937 (beginning of the Sino-Japanese conflict) put budgetary problems in the background. Rightly, the most powerful model was chosen and homologated, after modifications, under the designation of medium tank type 97 "Chi-Ha".
The technique
The production tank differed from the prototype by the adoption of rubberized rollers, by its optics (periscopes and episcopes) and by its radio equipment.
Naturally, the manufacture was entrusted to Mitsubishi. The manufacturer had realized the relative fragility of the prototype's suspension, which had only five rollers on each side, of which only the first and the last were double, the other three simple, bearing alternately on treads. internal and external of the caterpillar.
Hence the realization of a model called "Chi-Ha prototype improved", then "experimental medium tank type 97 Chi-Ha", characterized by a set of three bogies with two double rollers on each side. Before the launch of the series, the spoke hubs were also replaced by disc hubs, and an independent suspension was created for the first and last pulley. The hull was made up of armor plates assembled by bolts and rivets, as were the curved plates of the turret, of asymmetrical shape.
The tank commander's cupola was at the top and on the right . It was closed at its upper part by two semi-circular panels in the center of which passed the tube of the periscope.
Inside the tank, to take account of the climatic conditions, the hull and the turret were coated with asbestos for heat protection. The armament, its only weak point, included a short 57 mm gun at the front of the turret, the rear sector of which was defended by a 7.7 mm Type 97 machine gun under a spherical casemate. There was another machine gun in the front of the hull, to the left of the pilot's hatch.
In many cases, the Chi-Ha was equipped with smoke launchers, four mounted in the turret, under the gun mantlet, and two others on the sloping front plate of the armor (one on each side).
The 12-cylinder V diesel engine proved to be excellent. It was fitted with overhead valves and removable cylinder heads. There were two interchangeable variants A and B, both of very low specific consumption.
On the outside, the machine sometimes had two boxes under the side grilles of the engine, plus two access panels, one at the front and one at the rear. On the right side, under the rear of the fender was the set of breakdown tools and the lifting jack. On the left side, the box containing the on-board kit and, at the rear, under the traffic lights, the housing for the towing cable.
The Type 97 Chi-Ha medium tank was most often equipped with a radio T/R with a very characteristic guardrail antenna at the top of the turret.
The type medium tank 97 was the subject of an enormous production effort on the part of the Japanese industry. Mitsubishi Tokyo had already delivered 1,120 units and 1,610 power units.
Hitachi participated in this effort and manufactured 355 more from February 1940 to November 1943. All these figures refer to the more powerful version Shinhoto Chi-Ha (with new turret) whose realization had been planned since the beginning of the program. (Hence the diameter of the circular turret, of an exceptional width for the initial armament). This solution had been adopted in haste after the d - Normonhan incident in 1939, during which the Japanese tanks had been in difficulty against the Russian tanks armed with the 45 m long gun.
The lesson was retained by the Imperial General Staff, which prescribed the mounting on the medium tanks of the 47 mm type 1 gun already in service (initial speed 800m/sec.) under a turret specially designed and produced:by the same Mitsubishi .
The Chi-Ha armed with the long gun d:47 mm made their first weapons in the spring of 1942. The new turret increased the total mass of the tank by 4.5 tons It also had the cupola on the right and two large rectangular hatches on the left. At the rear there was the ball mount for the machine gun and another hatch. The installation of the counter-aircraft machine gun was unchanged.
The first Chi-Ha armed with the 47 mm made their appearance with the combat in the spring of 1942. The new turret increased from:4 to 500 kg the mass of the tank. It also had 1:cupola on the right side and two large. rectangular panels on the left side. behind there was a spherical machine gun mount and a third panel. The support of the anti-aircraft defense weapon remained unchanged, but for the on-board radio equipment, the less visible and less vulnerable whip antenna was adopted. The engine side grilles, which have remained unchanged since the normal "type 97", were equipped on the new versions with armored air intakes opening under the mudguards.
The width of the caterpillar was increased to improve the maneuverability of the tank on soft ground, and the box with endowments mounted at the back of the mudguard was repositioned at the extreme rear of the body, which modified the silhouette of the machine .
The Imperial General Staff endeavored to return to the factory as far as possible all the medium tanks of the "Type 97" to make them receive the modifications required for the arming and checkout.
The excellent qualities of this chassis led it to be used for a wide range of specialized vehicles, such as the Shi-Ki command tank (equipped with a dummy gun in the turret and a 37 mm gun in
casemate instead, of the on-board machine gun), the tank-bulldozer No-K, the track opening tank (a normal Chi-Ha with a turret armed with the 47 mm, equipped with a clearing blade (scraper), the Chi-Yu mine-clearing tank, the various variants of the Ri-Ki recovery, and the bridge launcher tank.
More numerous still were the self-propelled of various models which used the hull of this medium tank. First was the self-propelled Ho-Hi gun, essentially a normal Chi-Ha without its turret carrying a slightly modified 75mm Type 90 gun. It had a muzzle brace, a somewhat shortened mount and a slightly shorter horizontal wedge shutter. The servants of the piece were protected on three sides by a fairly robust mask, the thickness of which reached 50 mm in the frontal part.
This self-propelled self-propelled put into service in 1943, with a little more than 100 copies, was followed by a whole family of self-propelled self-propelled similar configuration armed with 100 mm guns and 150 mm howitzers , designated Type 2 and Type 4 respectively. The Type 3 was armed with a 75mm gun in a swivel turret.
Medium tanks of type 97 and their derivatives of types 1 and 2, as well as self-propelled guns of their parentage (Ho-Ni 1, armed with the 75 mm type 90, type 2 armed with a 100 mm gun, type 4 armed of a 150 mm howitzer, and type 3 equipped with a mobile turret equipped with the gun of 75 mm) formed the bulk of the Japanese armored divisions throughout the duration of the war. They fought on all fronts, with results often exceeding all expectations. The self-propelled, on the other hand, were most often confined to the role of static defense.
There are still a few examples in museums in the United States, Australia and, of course, Japan.