Japanese mini submarine tested according to the Dutch magazine Marineblad dated 1934 no. 4

An item referred to the magazine M.R. dated May 1934 reporting that the first test with the Japanese mini submarine were successful. With as dimensions 8,8 x 2,3 metres was her displacement 12 ton. Electric propulsion by 50-2 Volt batteries and 50 amp. Allowing a submerged speed of 3,3 knots. She was able to stay 3 hours under water on a depth of 50 metres. Her crew numbered 4 men. The armament consisted of 1 machinegun and 1 torpedo tube. The sub was transported on 28 December 1933 from Tsukischima towards Ito (Izu) for trials during a period of 2-3 months. One of the tasks of the recently commissioned mother ship for submarines Taigei built at the navy yard Yokosuka was transports such subs to the operation field.