History

The story starts in early 1944 when Japan's Emperor Hirohito wanted a versatile tank equipped with a 12 cm Type 98 L/57 cannon. This project was called Medium Tank No.5. Even though Japan was already planning to build the Type 5 Chi-Ri, Hirohito wasn’t satisfied with its design, thinking it was too outdated—especially with its hull-mounted 37 mm coaxial gun, which had limited range.

Because of this, Hirohito wanted a medium tank that was cheap to produce but as powerful as the Tiger II. Many people pitched their tank designs, but nothing really impressed him. Then, a Japanese military engineer came up with a concept Hirohito liked—a tank named Shi-Ro.

This is where the development of the tank began. One prototype was built and tested in Japan’s forests, and the results were very impressive. However, the project was abandoned after Japan surrendered to the Allies, leaving the tank forgotten.

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Specifications

Type: Medium tank

Weight: 54-60 tons

Length: 6.9 meters (11 meters with main gun)

Width: 3.42 meters (3.44 meters with side skirts)

Height: 2.41 meters

Crew: 5 (Commander, Gunner, Driver, Radio Operator, Loader)

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Armor:

Hull:

1. Upper glacis: 170 mm @62° = 362 mm

2. Lower glacis: 100 mm @60° = 200 mm

3. Upper side plate: 130 mm @30° = 150 mm

4. Lower side plate: 100 mm

5. Rear plate: 82 mm

6. Side skirt thickness: 10 mm

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Turret:

1. Front: 245 mm @43° = 335 mm

2. Sides: 150 mm @25° and 26° = 184 mm

3. Rear: 100 mm

4. Gun mantlet: 250 mm

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Main Armament

12 cm Type 98 L/57 Cannon
Can fire the following shells:

1)APCBC

2)HE

3)HEAT

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Penetration

1. APCBC penetrates 330 mm of armor, weighs 23.25 kg, and has a muzzle velocity of 1,052 m/s.

2. HEAT penetrates 350 mm of armor, weighs 23.25 kg, and has a muzzle velocity of 900 m/s.

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Secondary Armament

1x 20 mm Autocannon

1x 7.7 mm Coaxial Machine Gun

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Performance:

Max speed: 58 km/h

This tank was designed to replace the Type 5 Chi-Ri and the heavy tank concept Ju-Nu by combining the armor and firepower of a heavy tank with the size and speed of a medium tank.

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Additional Features:

1)It had an Assisted Loading Mechanism, reducing its reload time to 8 seconds.

2)The transmission was located at the rear.

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The Misconception:

Many people mistakenly think this is either a medium tank or a heavy tank, but based on its specs, it’s actually a Main Battle Tank (MBT).

The Shi-Ro had nearly the same weight as a heavy tank but served the same role as a medium tank. However, the Japanese engineer never officially called it an MBT because MBT type tank only appeared after the British introduced the Centurion tank.