Type 61 MBT (Family)
The Type 61 MBT () was a main battle tank of the Japanese Ground Self-Defense Force (JGSDF). Built and designed by Mitsubishi Heavy Industries.
Development started in 1955 with the ST-A series of prototypes and the vehicle was first deployed in April 1961. A total of 560 Type 61s were manufactured between 1961 and 1975 as it was succeeded by the Type 74.
After Japan's unconditional surrender at the end of World War 2, the shattered empire had been deprived of the opportunity of developing their own armoured vehicles. In the years following, the Japanese were heavily restricted in their military. They were limited to a Police Force in 1950, and by 1954 they were permitted to form a National Defense Force with the sole purpose of maintaining their borders without relying on the United States Military. This action was detailed and enacted through the U.S and Japan Mutual Defense Assistance Agreement. With the tensions between the Communist’s and the free world simmering up, the Japanese knew that at some point, they too would need their own tanks. Until then they had been using leased Sherman, Bulldog, and Chaffee tanks in their arsenal.
One year after the Japanese Self Defense Force (JSDF) was formed, development on their first post-war tanks began with two roles: a main battle tank and a tank destroyer. The tank destroyer would start its prototype stages as designation SS and would eventually be developed into the Type 60 SPRG. The main battle tank would start development under the designation of ST-A (Special Purpose Vehicle A), and was to be in the same vein as the M47/M48 90 mm's as inspiration for the main gun. As the U.S Military gave a green light to the Japanese to aid one another in technological advancements, development on both projects could start. Originally, Keeping the weight low, the official project's goals were a weight of 25 tons, with a strong engine output and low ground pressure overall. Coupled with this equipped with a high penetration 90mm anti tank cannon. Provided with good depression, off road capabilities, and managing terrain such as beach heads and rice fields. But it became clear to Japan that their tank had to weigh at least 30t to be given necessary armour protection.
To fulfill the military’s requirements, tank designers offered several promising projects, the first of which was the ST-A1. The tank ended up quite compact, with a height of only 2.2 meters. This allowed it to have excellent cover abilities, with a cast turret and traditional Japanese tank layout: the engine installed behind the transmission.
Two finished vehicles of this model were built. Despite the fact that the ST-A1 series did not continue, it was a starting point for the future of Japanese tank development.
- From Devblog
The ST-A2 medium tank was finished by February 1957, and differed from the ST-A1 in a range of characteristics. The vehicle was made 20 centimetres taller and half a metre shorter in length. This reduction in length also allowed for a reduced number of lower track rollers and supporting wheels. The new vehicle had an altered turret shape which had been made longer, and its rear contained a compartment for a radio. With the aim of increasing the tank’s survivability, the upper frontal hull received characteristic side angles which increased the chance of a ricochet off the hull. The ST-A2’s tracks were also redesigned and equipped with more advanced cleats designed to raise the vehicle’s mobility and road characteristics. Other than this, its composition remained identical to that of the ST-A1. The diesel engine was housed in the rear of the hull, while the transmission remained in the front. The armament on this Japanese tank was American through and through. The 90mm M3A1 cannon was borrowed from the M46 tank, and it was accompanied by two different calibre Browning machine guns.
Only two experimental prototypes of the ST-A2 were built. They underwent testing, but were never accepted into service.
- From Devblog
The ST-A3 was created as one of the later prototypes and was based on the previous design - the ST-A2. Featuring a 90 mm cannon coupled with an autoloading mechanism in the rear of the turret, the design was considered successful, but ultimately wasn’t ordered into production due to concerns over its cost. As a result, the ST-A3 was modified into the ST-A4 by having its autoloading mechanism removed and eventually entered production as the Type 61 medium tank in 1961.
Only two ST-A3 prototypes were constructed and closely resembled the later production model Type 61 visually.
- From Devblog
In the early 50s, the Americans provided Japan with the M47 Patton which was evaluated in trials only. The new tank was entirely unsuitable for the Japanese as it was too heavy to be used on japanese terrain. For this reason, the decision was made to develop a similar, but smaller tank and produce a Japanese 90 mm cannon that was influenced by the design of the American 90mm. Various prototypes that varied in different details were provided for testing. The first was the ST-A1 with a low profile (its maximum height, it was just 2.2 meters!). Variants were developed based on the ST-A1 with taller and shorter hulls, receiving the designations ST-A2, ST-A3 and ST-A4. They differed in the design of their turrets and commander cupolas. After successful tests, the ST-A4 variant was accepted into service with the JSDF under the designation of Type 61.
- From Devblog
- [Devblog] ST-A1: Stepping into a New Era
- [Devblog] ST-A2: One Step Closer to the Goal
- [Devblog] ST-A3: The Fastest Gunslinger in the East
- [Devblog] Type 61: The Japanese-style Patton
|Mitsubishi Heavy Industries Ltd. ()|
|ST-A1 · ST-A2 · ST-A3 · Type 61|
|ST-B1 · Type 74 (C) · Type 74 (E) · Type 74 (F) · Type 74 (G)|
|Type 90 · Type 90 (B)|
|Jet Fighter||F-86F-30 ▅* · F-86F-40 ▅* · F-86F-40 JASDF▅*|
|T-2 · F-1|
|F-4EJ Phantom II* · F-4EJ Kai Phantom II*|
|MHI's shipyard is positioned in Shimonoseki|
|See also||Mitsubishi Aircraft Company (1928-1945) · North American Aviation · Lockheed · McDonnell Aircraft Corporation|
|Japan medium tanks|
|Type 97||Chi-Ha · Chi-Ha Kai · Chi-Ha Kai TD · Chi-Ha Short Gun|
|Type 1||Chi-He · Chi-He (5th Regiment) · Ho-I|
|Type 3||Chi-Nu · Chi-Nu II|
|Type 4||Chi-To · Chi-To Late|
|Type 5||Chi-Ri II|
|Type 61 MBT||ST-A1* · ST-A2* · ST-A3* · Type 61|
|Type 74 MBT||ST-B1* · Type 74 (C) · Type 74 (E) · Type 74 (F) · Type 74 (G)|
|Type 90 MBT||Type 90 · Type 90 (B)|
|USA||▅M4A3 (76) W · ▅M47|
|*ST-X is prototype stage for said MBT|