I / Mi-To Super-Heavy tank (2024)

O-I (Oysha) was a multi-turret tank that was prototyped by the Great Japanese Imperial Army from 1941 (Showa 16). The "O-I car" is the name of the Army side, and the "Mito car" (abbreviation of "Mitsubishi Tokusshu Ryouou") is the name of the manufacturer. By one account, the designation O-I is an abbreviation of big or large, and I, which in Japanese army nomenclature refers to model number 1, from old Japanese alphabet iroha.

The Type 120 O-I is the most well known of Japan's multi-turreted heavy tank design of the Pacific War. There is however very little information available and the few sources often contradict each other, leading to speculation of multiple versions of this tank being designed over its development. From the history of the Japanese armored vehicles the least studied isi the construction of heavy tanks. Data on the work of designers on this class of technology is contradictory and scarce.

It was not positioned as a part of the national strategy, for example, like a Yamato-type battleship , but in a sense, it was in some sense personal research. It is reported that the O-I reached a wooden mockup stage near the end of the war but there are also rumors that one prototype was finished and tested in Manchuria but no evidence to support this has been found.

One of the least appropriate definitions for Japan in the first half of the twentieth century will be the word peace-loving. The Japanese fought a lot, and by the 30s their influence in the Far East was very great. Not the last role in the successes of the Land of the Rising Sun was played by the attentiveness with which the highest military ranks treated technical innovations in the field of armaments. Of course, the Japanese did not pass by such a promising innovation as tanks. Purchases of imported equipment began in Japan around 1917, and their own development took to the battlefield in less than 10 years. These were medium and light tanks, the combat power of which was enough, for example, for the war against China or (already during World War II) island garrisons that did not have heavy weapons.

The topic of heavy tanks was worked out by Japanese engineers long before the outbreak of World War II. The first project, embodied in the metal, was called "Type 91" or "2591", work on its design began around 1930. When creating their first heavy, the engineers used the experience gained in creating the medium Chi-E tank. Tomio Hara was in the design team that worked on the project, and he later emerged as the most famous Japanese tank designer.

In the pre-war period, the Japanese designers created two heavy tanks, the Type 91 and the Type 95. Neither of them were built in significant numbers and did not seriously fight. "Type 91" weighed only 18 tons, by the standards of Western Europe or the USSR, it was a medium tank. However, due to the fact that the main armament was a 70-mm cannon, the car was classified as a heavy tanks. Under the influence of the British armored school, for which, in the 1930s, multi-turreted tanks were almost the main “trend”, the designers equipped the Type 91 with three turrets along the hull. Only one instance was built in metal. And although, in general, it made a good impression on customers, the machine was not allowed to mass production - the military demanded a modernization.

"Type 95", the second and last pre-war "heavyweight" of the Japanese army, appeared in 1935. When creating a machine, designers focused on improving manufacturability and enhancing weapons. In particular, a 37-mm gun was added to the 70-mm cannon with a small initial velocity of the projectile, more suitable for combating defenses and manpower. At a distance of 300 meters, it punched up to 30 mm of armor. This potentially made the Type 95 a very dangerous enemy for the Soviet T-26 and BT with their thin armor.

In the Far East the “Type 95” had no equal in terms of armor and arming. At the same time, the military’s attitude towards the tank was controversial: they liked the fighting qualities, but the speed due to the large mass did not please them. It was decided to limit the construction of a small pilot batch, the order for which was received by the arsenal in the city of Osaka. It is not known how many vehicles left the assembly line, but modern researchers believe that there are hardly more than ten of them. Type 95 was used primarily in training units in Japan. It is known that in 1938, individual tanks were transferred to China and used in the final stage of the Sino-Japanese conflict.

The pinnacle of Japanese tank building could be "Mi-To", if it was built. In fact, this is a real tank puzzle. The data about the “super heavyweight” is contradictory and fragmentary. Three things are known for certain. First: work on the super heavy tank began after the defeat of Japan on the Khalkhin-Gol river in 1939. Second, it is not possible to speak of Mi-To as one specific tank. It was a whole series of development work, which lasted until Japan surrendered in 1945, and included several different projects. Third: all projects of super-heavy Japanese tanks were multi-turreted.

The long history of Mi-To was cut short with the end of the war. Was at least one prototype built? According to the book «Imperial Japanese Army Land Weapon Guide», one was built. The only prototype produced was a vehicle with a planned weight of 150 tons. After the work was completed, it was dismantled and sent to Manchuria for field tests, which revealed serious problems with the reliability of the undercarriage. The Soviet Union reported that the Japanese installed a Daimler-Benshi DB 601A engine on a wooden O-I model in 1945, while other materials claimed that the rest of the car was dismantled in 1945. However, like most information about Japanese super heavy tanks, this data is not 100% accurate. It can not be said that the role of Maj. Gen. Iwashima, who was considered to be the proposer and promoter of this tank, has been completely elucidated. It seems that most of the documents were disposed of.

It is safe to say that there was no possibility that the planned vehicles could be completed. It was impossible to get the planned speed, and even from the test results of the prototype, it is pointed out that the strength of the running gearing is insufficient, and it seems that the rigidity of the car body was lacking. The military requirements were vague and there is no necessity for development. It seems that it was made with the idea let's make a heavy tank design as a heavy-weight moving structure, rather than a tank, without considering practical uses.

The vehicle was actually built, in prototype form. Beyond that, the vehicle completely disappears from history. A long treasured story of obscure trivia fanatics says that the hull and turret were shipped separately to Manchuria. Perhaps this makes sense, if the Japanese had hoped to hide the design from invading Allied forces, or perhaps the Japanese had intended to use it against the advancing Soviets. At any rate, the vehicle was never reported in combat by the Soviets (or anyone else), and it is, in short, a complete mystery. A sort of Japanese "Maus".