Type 89B Ot-Su Medium Tank

Last updated on February 17th, 2019 at 09:49 pm

Japan’s Type 89 medium tank, which was designed in 1929, was based on the Type 89 light tank, which was in turn based on Britain’s Vickers Medium C.

The Type 89B Ot-Su medium tank was a diesel version of the Type 89 medium tank. It was developed by Mitsubishi in 1935.

There were two versions of the Type 89B Ot-Su medium tank. In the first, the front plate was made of one piece. There was a door on the right side. The driver was on the left. The main weapon was a Type 90 2.24 inch (57mm) machine gun. There was also a 0.256 inch (6.5mm) machine gun in the back of the turret, and another 0.256 inch (6.5mm) machine gun at the right side of the front plate.
Type 89B Ot-Su medium tank Source: Florida State University
This earlier version had five girder-mounted return rollers.

In the second version, the driver was on the right and the machine gun was at the left of the front plate. The five girder-mounted return rollers were replaced with four return rollers.

During World War II, the Ot-Su was a poor match for Allied tanks, as it did not have comparable armor or weaponry.


Type 89B Ot-Su Medium

Active: 1936
Crew: 4
Weight: 12.8 tons (13,000 kg)
Length: 18ft 9.5in (5.73m)
Height: 8ft 5in (2.56m)
Width: 7ft (2.13m)
Weapons: Main – 2.24in (57mm) gun, Secondary – 2 x 0.256in (6.5mm) machineguns
Armor Maximum – 0.67in (17mm)
Engine: Mitsubishi 6-cylinder diesel, 120hp
Speed: 16.2mph (26kph)
Range: 105.6 miles (170 km)