The Type 97 Chi-Ha was the most widely produced Japanese Medium Tank of WW2. It was used before, during and after WW2 in the Pacific War, including China and the Kuril Islands. With thin Armour, a relatively small Main Gun and an underpowered engine, it was less effective than most Allied designs. Postwar, a few were used by the Chinese People's Liberation Army. It's low silhouette, aerial spread around the vehicle top, asymmetric turret, complicated body front, and seesaw-type suspension system combined to give the tank a unique appearance that distinguished it from other Japanese Tanks of that time. The Type 97 was a development of the Type 95 Ha-Go Light Tank and reflects the process of modernisation of Japanese Tank Warfare prior to WW2. Development With the Type 89 Chi-Ro fast becoming obsolete in the late 1930's, Japan chose a design by Mitsubishi as its replacement for the role of Infantry Support and began production in 1937. The Chi-Ha tank was designed to be a scaled up version of the Type 95 Ha-Go Light Tank with a 2 man turret, thicker Armour and more power to maintain performance despite it's considerable weight of 15 tonnes. At that time, the Japanese Imperial Army was divided in to 2 Camps as to what sort of a tank to build. The Imperial General Headquarters, The Osaka Arsenal & the Ministry of War wanted to build as many small & inexpensive Tanks as soon as possible. Troops at the front, the Sagami Arsenal & other Army experts wanted heavier Tanks with better performance. Since both sides held their positions, it was decided to make and study 2 different experimental Tanks. This was very different from the conventional practice of giving the same specifications to several competitors and having each of them make their own experimental vehicle. The advantages & disadvantages of the 2 types was clear from their design drawings. Therefore, the difference of oppinion that existed before the design stage remained unchanged even when the experimental vehicles were completed. The Tokyo factory of Mitsubishi Heavy Industries completed an experimental vehicle called Chi-Ha and the Army's Osaka Arsenal completed the Chi-Ni. Chi came from Chusen-Sha (Medium Tank). Ha & Ni equate to C & D making the Chi-Ha the "Medium Tank Model 3" and the Chi-Ni "Medium Tank Model 4" The Japanese successfully put their first Air-Cooled Diesel Engines in to practical use in 1936. There were several reasons why the Japanese developed and adapted them for use in Armoured Vehicles instead of Petrol Engines and Water-Cooled Diesel Engines. Experience with Petrol Engines showed they might catch fire when they backfired or when the vehicle received a direct hit. Petrol Engines consumed more expensive refined fuel, and Japan's lack of oil resources made it difficult to supply Armoured Units with sufficient Petrol & refined fuels in Wartime. Air-Cooled Engines were more practical in areas where water was in short supply. As they could not agree, 2 different prototypes were made; the Chi-Ha & the Chi-Ni. The prototype Chi-Ha was 13.5 metric tonnes in weight, a speed of 35 kmh and had a 2 man turret. The Chi-Ni weighed 9.8 metric tonnes, had a speed of 30 kmh and had a 1 man turret. The Armour of both prototypes was 25mm thick. Though the Tank Force had requested 30mm thick Armour, they accepted the lesser amount because of the weight requirement. The Chi-Ha had 33mm of Armour on the turret front, 22mm on the hull front, but only 9mm on the hull sides. Much less than the contemporary British Matilda Tank and soon all Allied Tank Designs would leave it behind. An Air-Cooled V-12 Engine engine was developed for the Chi Ha which gave 170 hp. 2 experimental versions were made, one by Mitsubishi the other by Ikegai Iron Works Ltd. The Mitsubishi version was chosen by the IJA to be fitted in the Chi Ha. Whilst still in the production phase the war in China had escalated on 7th July 1937. Peacetime budgetary limitations were lifted, and the Chi Ha was accepted as a new Medium Tank. In June 1937 it was tested at the Army Tank School in Chiba. The 2 improved prototypes were tested in January 1938. In the same year the design with independantly sprung first & sixth road wheels was officially accepted for production. Known as the "Type 97 Medium Tank" it was conventionally shaped & modern, quite unlike the Type 89 Chi-Ro Medium Tank. The Type 97 was Armed with a 57mm Type 97 Main Gun. It was a short barrelled cannon with a relatively low muzzle velocity but sufficient as the tank was intended for infantry support. However it proved insufficient against Armoured Vehicles. It also carried 2 7.7mm Type 97 Machine Guns, one on the front left of the hull, the other in a ball mount on the rear of the turret. This could also be mounted on top of the turret for Anti-Aircraft use. The turret could be traversed in a full 360 degree circle with the main gun also having an independant 10 degree traverse of the turret. A small periscope was fitted for use when the Tank was "buttoned up". The transmission was of the sliding selection type. It had 4 forward and 1 reverse speeds with high/low change-over. The Chi Ha was capable of 42 kmh but for practical reasons was limited to 38 kmh. Any faster and the rubber road wheels were prone to overheating. The Shinhoto Chi-Ha The Type 97 was superior to the Type 89 in a number of ways. However, it retained the same short barelled 57mm gun. The designer Tomio Hara was not satisfied with it and thought that the new tank should be armed with a high velocity cannon, designed specifically for tank on tank combat. The Army did not agree as they were satisfied with the existing gun. Their focus was on China where there were no tank on tank encounters. The shortcomings of the 57mm gun became clear at the "Nomonhan Incident", where soviet tanks' 45mm guns outranged the Japanese 57mm weapon and as a result the Japanese suffered heavy losses. This convinced the Army that a new weapon was needed, and in 1939 began development of a new gun. The new 47mm Tank Gun was completed in 1941. Although it was a smaller calibre weapon, it used a longer barrel and its armour penetration was superior to that of the 57mm gun. When the Pacific War began, the 47mm armed Chi-Ha was still being tested. During the invasion of The Phillipines, Japanese Tanks met the US Army's M3 Stuart Light Tank. The M3 had relatively thick armour which the Japanese tank guns couldn't penetrate. The Japanese rushed the new Shinhoto Chi-Ha tanks to the Phillipines. The new 47mm gun of the Shinhoto Chi-Ha was tested against a captured M3. At a range of 1000 metres, 3 out of 6 hits penetrated the front armour. At a distance of 800 metres 6 out of 9 hits penetrated. However, The battle of the Phillipines ended without a confontation between the M3 Stuart and the Shinhoto Chi-Ha. From 1942 onwards, The Type 97 was armed with the high velocity "Type 1 47mm Anti-Tank Gun" in a new larger turret. This was the "Type 97 Improved Medium Tank" or "Shinhoto Chi-Ha" (new turret). The design was probably the best tank Japan produced up to 1945. Shinhoto Chi-Ha was essentially the hull of the Type 97 fitted with the turret of a Type 1 Medium Tank, complete with long barrelled gun. This increased weight to 16 tonnes, but the longer gun provided a higher muzzle velocity and greater armour-penetration capability. The Type 1 47mm Gun was derived from captured Soviet Anti-Tank Guns at the Nomonhan battle and the German PAK 35/36 37mm AT gun, captured from Chinese forces. Examples of the German Cannons were modified in Japan in to the Type Ra 37mm AT Gun. They were deployed at Guadalcanal & other locations during the war. Combat History The Type 97 Medium Tank first saw action in the Nomonhan Incident of July 1939. The 3rd Tank Regiment of Yasuoka's Detachment Force had already received Type 97's as substitutes for existing Type 89's, but the regiment had only replaced 4 by the time of the incident. During fierce fighting with Russian forces, the regimental commanders' vehicle was hit and Colonel Yoshimaru was killed. This was a grave warning that the Type 97 had not been designed with regard to Tank Fighting. However, Japan entered WW2 proper before sufficient countermeasures were considered. On the 8th December 1941, the Japanese started their offensive in Malaya. The 3rd Tank Group had been incorporated into Lieutenant-General Yamashita's 55th Army on 25th December. It's 1st, 6th & 14th Tank Regiments took active part in operations. The 1st Tank Regiment was under 5th Division, which formed part of the Army's main group. The regiment was amongst the 1st landing troops at Singora (Songkla) in Southern Thailand. One of it's medium Tank Companies was the 3rd Tank Company under 1st Lieutenant Yamane (10 Chi-Ha medium tanks & 2 Ha-Go light tanks), forming part of Saeki Detachment. The company was in the vanguard of the attack and succeeded in breaking through the British defensive positions. Later, the same group participated in the Burma Campaign, and another section of this unit was formed in Manchukuo (Manchuria) with medium tanks & self popelled guns. The Type 97 was due to be replaced by the new Type 1 Chi-He but, as deliveries of those tanks were delayed, the new turret design of the Chi-He with it's 47mm Gun was fitted to the Type 97's then in production to create the Shinhoto Chi-Ha. The upgunned variant was used for the 1st time in the Battle of Corregidor. Chi-Ha & Shinhoto Chi-Ha tanks were also used by Japanese Special Naval Landing Forces (Equivalent to Marines) & Naval Infantry armoured forces in the Pacific & in defence of the Home Islands in anticipation of enemy invasion. A special Chi-Ha s SP variant was developed with a 120mm main gun for defense of Metroplitan areas in particular. Production The Type 97 was manufactured by Mitsubishi Heavy Industries (1224 machines), Hitachi Industries (355 machines), as well as some limited production at the Army's Sagami Arsenal. A total production run of 2123 Tanks were constructed between 1938 & 1943. This included the Shinhoto Chi-Ha with 47mm Type 1 AT Gun. Lesser in number than the Type 95 Ha-Go Light Tank but still the largest number of medium Tanks built by Japan during WW2. No new Type 97's were built after 1943. After this time a new Tank, The Type 1 Medium Tank and Type 1 Self Propelled Gun were on the production line, although by this time the Japanese were losing the war and much of the raw materials needed to build the new machines were getting no nearer to Japan than the bottom of the sea, because of US Navy Submarines attacking the Japanese Merchant Fleet on it's way to & from the earlier conquests in Asia. So these would only play a very limited role in subsequent operations due to their small numbers. Type 97 Shinhoto Chi-Ha on display at the US Army Ordnance Museum, Aberdeen, Maryland. Type 97 Chi-Ha Tank at Yasukuni Shrine. Type 97 Chi-Ha Tank in Burkit Timah.