Type 98 Ke-Ni

The Type 98 light tank Ke-Ni (九八式軽戦車 ケニ) was designed to replace the Imperial Japanese Army's Type 95 Ha-Go light tank, Japan's most numerous armored fighting vehicle during World War II. It is also referred to as the Type 98 Chi-Ni by some sources

History and development
Although developed in 1938 to address deficiencies in the Type 95 design already apparent from combat experience in Manchukuo and China in the Second Sino-Japanese War, the Type 98 design was shelved until 1942. This can be attributed to the adequate performance of the aging Type 95 against the ill-equipped National Revolutionary Army of the Republic of China forces, which lacked tanks or anti-tank weapons. Furthermore, the bulk of Japan's steel went to shipbuilding and aircraft production, rather than armored fighting vehicles.

With the start of World War II, the Imperial Japanese Army General Staff quickly realized that the Type 95 design was no match for contemporary Allied designs, such as the M4 Sherman or the M3 Stuart tanks. A production contract for the Type 98 was awarded to Hino Motors and Mitsubishi Heavy Industries in 1942, but only a total of 103 Type 98s are known to have been built>: 24 in 1942 and 79 in 1943.

Design
The design of the Type 98 was very similar to that of the Type 95, but with thicker, welded armor of improved shape, including the use of a Mitsubishi Type 100 6-Cylinder air-cooled diesel engine, rated at 130 HP, and located sideways to make maintenance easier. Slightly lighter and shorter than the original Type 95, it could travel at 55 km/h even with its thicker armor.

The Type 98 had a conventional two-man turret, an improvement on the asymmetrical turret used on the Type 95, carrying a Type 100 37mm tank gun, with a muzzle velocity of 760m/s, and with a coaxial 7.7mm machine-gun to the side.

Variants

 * Type 98A Ke-Ni Ko (九八式軽戦車（甲型）)
 * This was the standard production model of the Type 98 with three pairs of bogies with six road wheels connected to the chassis using bell cranks, which transferred any movement in the bogies into sideways motion that was absorbed by springs.


 * Type 98B Ke-Ni Otsu (九八式軽戦車（乙型）)
 * This was an experimental model, developed with a five-wheel Christie-type suspension with large road-wheels supported by side-ways facing coil springs. It never entered production.


 * Type 2 Ke-To
 * An improved Type 98-B with a more powerful Type 1 37 mm tank gun with a muzzle velocity of 810 m/s. Production of the Type 2 Ke-To began in 1944 but only 29 units were built.


 * ''Ta-Se 20 mm Anti-Aircraft Tank
 * In November 1941, development bagan on an anti-aircraft version of the Type 98 based on Type 98 chassis with a 20mm AA gun converted from a Type 2 20 mm AA Machine Cannon in a circumferential protected turret. The single prototype was designated "Ta-Se", for "Taikū (Anti-air) sensha (tank)". In trials, it failed to exceed the performance of the cancelled Ki-To program, and plans were made to develop a twin gun version, for completion in March 1944. The project was  canceled in 1943.