The Dai-chi Osaka Sensha (First Osaka Tank), or Number 1 Chi-I, was the first tank to be designed in Japan. As the name indicates, it was designed by the Osaka Arsenal. Work began in 1925, and the prototype was complete by February 1927.
The Number 1 was a twin-turreted tank weighing somewhere between 20 and 22 tons (sources differ). The main 57mm cannon was carried in the main turret towards the front of the tank, with one 6.5mm machine gun in the hull front and one in a rear turret. The 140hp engine was placed in the middle of the hull. The Number 1 tank had nineteen small road wheels on each side.
The Number 1 tank was the first of a series of unsuccessful designs for heavy multi-turreted tanks. It was rejected by the Japanese Army because of its poor speed and inability to negotiate obstacles. The Number 1 was modified to create the Experimental Heavy Tank of 1930 by removing 2 tons of armour, reducing the number of bogie wheels on each side to 17 and replacing the 57mm gun with a 70mm gun. This tank also failed to enter production. It was followed by the Type 91 Heavy Tank.
Dai-chi Osaka Sensha (First Osaka Tank) (Sensha = Tank, Dai-chi = First/ Number One)
Weight: 20-22 tons
Engine: 140hp gasoline engine
Max Speed: 12.5mph
Main gun: One 57mm gun
Secondary guns: Two 6.5mm Type 38 machine guns in front and rear turrets