Type 5 Chi-Ri

The Type 5 medium tank Chi-Ri was the penultimate medium tank developed by the Imperial Japanese Army in World War II. Intended to be a heavier, more powerful version of Japan's sophisticated Type 4 Chi-To medium tank, in performance it was designed to surpass the US M4 Sherman medium tanks being fielded by the Allied forces. The single prototype was still being built when the war ended.

Country Name Origin Year
Japan 1945
Country Name Operational Year Retirement Year
Japan View

A single unarmed prototype of the Type 5 Chi-Ri was completed by May 1945. The project was abruptly abandoned to free up manpower and critical resources to concentrate on the development and production of the more practical Type 4 Chi-To medium tank. As with many innovative weapons projects launched by Japan in the final days of World War II, production could not advance beyond the prototype stage due to material shortages, and the loss of Japan's industrial infrastructure to the Allied bombing of Japan.

The Type 5 Chi-Ri featured a lengthened version of the Type 4 Chi-To chassis, with eight road wheels per side instead of the Chi-To's seven. It had the usual Japanese track arrangement with forward mounted drive sprockets and rear mounted idlers. The Type 5 Chi-Ri had sloped welded armor, with a maximum thickness of 75 mm at the front hull; 25–50 mm on the side; 50 mm on the rear and 50 mm on the turret.

The Type 5 Chi-Ri was initially to be powered by a Mitsubishi Diesel engine, but the advancements needed to provide the necessary horsepower fell behind schedule, and an 800 hp V-12 gasoline-fueled aircraft engine designed by BMW in Germany and licensed to Kawasaki Heavy Industries in Japan was selected instead. The "Kawasaki Type 98 800 HP engine Ha-9-IIb" was detuned for the tank to 550 hp.

Originally, the prototype tank was to be fitted with the same Type 5 75 mm Tank Gun (based on the Type 4 75 mm AA Gun) used on the Type 4 Chi-To. However, eventually an 88 mm gun (based on the Type 99 88 mm AA Gun) was planned for the turret; a secondary weapon of a front hull-mounted Type 1 37 mm tank gun was fitted in the position normally taken by a machine gun. There was a ball mount for a Type 97 light machine gun on the left side of the turret for use in close combat situations. According to another source, the design called for two Type 97 light machine guns.

As with the Type 4 Chi-To medium tanks, the Type 5 Chi-Ri tanks were earmarked for the final defenses of the Japanese home islands against the expected Allied invasions. Army planners envisioned large armored divisions equipped with the Type 5 medium tanks driving the invaders back into the sea, but the war came to an end before even the first prototype could be completed.

The single prototype Type 5 was seized by American forces during the occupation of Japan, but its subsequent fate is unknown. One theory is that it sank in the ocean when a freighter taking it to the Aberdeen Proving Grounds capsized in a typhoon; another theory is that it was scrapped for its metal armor during the Korean War.

Other DesignationsType 5 Chi-Ri
Production QuantityprototypeProduction Period1945
TypeMedium TankCrew5
Length /hull (m)7.30Barrel Overhang (m)n.a.
Width /with skirts (m)3.05Height (m)3.05
Combat Weight (kg)37000Radio Equipmentn.a.
Primary Armament75mm Gun Type 4Ammunition Carried50
Traverse (degrees)(360°)Elevation (degrees)n.a.
Traverse speed (360°)n.a.Sightn.a.
Secondary Armament1 x 37mm Gun Type 1Ammunition Carriedn.a.
2 x  7.7mm Type 97 MGn.a.

Engine Make & ModelBMWNo. of Links/Trackn.a.
Type & DisplacementV12Track Widthn.a.
Horsepower550hp@1500rpmTrack Ground Contactn.a.
Power/Weight Ratio14.9 hp/tGround Pressuren.a.
Gearboxn.a.Ground Clearance (m)0.42
FuelGasoline (Petrol)Turning Radius (m)n.a.
Range on/off road (km)200Gradient (degrees)35°
Mileage (liters/100km)n.a.Vertical Obstacle (m)n.a.
Fuel Capacity (liters)n.a.Fording (m)1.20
Speed on/off road45 km/hTrench Crossing (m)2.70
Armor (mm@degrees)FrontSideRearTop/Bottom
Hull12mm to 75mm

End notes