Japanese Empire (1944)
Heavy Amphibious Tank protoype


Type 5 To-Ku 特五式内火艇 トク (1945). This last and ultimate Japanese IJN amphibious tank was particularly massive, built on the chassis of the Type 5 Chi-Ri, with the same water-cooled 12-cylinder Mitsubishi diesel, supplying 240 hp.

It had quite extensive armor protection (from 10 to 50 mm/0.4-1.97 in), it was fitted with a 47 mm (1.85 in) Type 1 gun in the casemate, and a secondary 25 mm (0.98 in) AT light gun Type 1 in the turret, plus two Type 97 machine guns. It weighed 29.1 tons but was utterly slow at 32 km/h (20 mph) on land and 10 km/h (6 mph) on water.


The Type 5 To-Ku was essentially on the same vein as the previous Japanese amphibious tanks, such as the Type 2 Ka-Mi, and the Type 3 Ka-Chi. This was a central hull on which 2 pontoons were added to the bow and rear.

In total, the To-Ku was 35.4 feet long for 11.8 in width and 12.7 in height. It was assembled after welded rolled homogeneous steel plates, 10 to 50 mm (0.4-2 in) in thickness. Total weight, battle ready was 29.1 short tons, for a crew of 5 (driver, commander, gunner, loader, hull gunner/radio operator).

Propulsion was assured by a Water-cooled 12-cylinder Mitsubishi diesel, 240 hp and 8 hp/ton, for a top speed of 32 km/h (20 mph) on land and 10 km/h (6 mph) on water. The drivetrain comprised four bogies with four doubled road wheels each, suspended by Bell cranks.

The turret of the To-Ku modified from the Chi-Ha Shinoto’s. This carried a 25 mm (0.9 in) Type 1 gun, and 2 x 7.7 mm type 97 (0.3 in) machine-guns. The Tanks main armament was a 47 mm (1.85 in) gun, mounted in the forward hull.

A single prototype was built and later captured by US troops in 1945. The Type 5 To-Ku never saw service. There is no known photo of this tank.

Type 5 To-Ku

Dimensions 10.8 x3.6 x3.88 m
Weight 29 long tons
Crew 5 (driver, commander, gunner, loader, hull gunner/radio operator)
Propulsion 12-cyl Mitsubishi diesel 240 hp
Speed (road) 32/10 kph (land/water)
Armament 47mm, 20mm, 2x 0.8mm
Armor 10 to 50 mm/0.4-1.97 in
Total production 1 Prototype

Type 5 To-Ku in a fictional regular Imperial Japanese Navy blue-grey livery, trials, 1945.

Type 97 Chi-Ni
Type 5 Chi-Ri
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