IJN Mini submarine

KORYU Target A Type-D

As seen in 1945

Pit Road no.W45

Scale 1:700 Water Line Series

Click on the pictures to enlarge.



2 3 4


These were a further improvement of the midget submarine design, featuring a 100-kilowatt diesel generator resulting in a greater operating range, with a full battery self-charge possible in eight hours, or less than one-half the time required in the Type C midget. Submerged endurance was 40 minutes at 16 knots and 50 hours at 2.5 knots. Also, the crew was increased to five men.

The shortage of 18-inch torpedoes at the end of the war led some of these craft being fitted with an explosive charge for use as a kaiten suicide submarine. Some Type D midgets were provided a taller conning tower and two periscopes for use in the training of kaiten pilots.

A total of 540 of this type were planned to be in service by September 1945, with a maximum production rate of 180 units per month through mass-production techniques. The HA-77 (Prototype) was laid down in June 1944 and completed in January 1945.

Technical specification:

Displacement 60.3 tons submerged
Length 26.2m
Width 2.0m
Draught 2.8m
Machinery 1-shaft diesel and electric motor, 150bhp surface, 500 shp submerged
Speed 8.0kt surface, 16.0kt submerged
Armament 2-45cm TT
Complement 5



Books form my own library :  

Japanese Naval Warship Photo Album Submarines and depot ships

from Diamond Sha books.  


Submarines of the Imperial Japanese Navy 1904-1945 from Conway Maritime press

(Pictures and history)

The building time was a matter of hours 

Mar. 2009

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