Type C3

The Type C3 was developed from the Type C1 and C2, with less powerful engines, fewer torpedo tubes, an extra main gun, and increased range.   The reduction in installed power was due to difficulty of producing high-powered diesels in wartime.

At least some of these boats were later fitted with snorkels, and I-53 was also modified to carry six Kaiten.  Seventeen further Type C3 units were cancelled, as were 25 units of a subsequent Type C4.

Bagnasco credits the Type C (C1, C2, and C3) submarines with sinking 16 merchant and auxiliary vessels for a total of 80,660 tons.

I-52 was lost to aircraft from USS BOGUE 800 miles southwest of the Azores while carrying rubber, gold, quinine, and Japanese engineers to German-occupied France, on 24 June 1944.  I-53 survived the war, only to be scuttled off Goto Island in 1946.  I-55 had been in commission only 3 months when destroyer escorts USS GILMER and the WILLIAM C. MILLER put an end to her off Saipan on 14 July, 1944. 

Units 3 (one survived)
Ships I-52, I-53, I-55
Year(s) Completed 1943-1944
Displacement 2,564 tons / 3,644 tons
Dimensions 356.5 ft x 30.5 ft x 16.75 ft
Machinery 2 diesels: 4,700 hp

electric motors: 1,200 hp

Speed 17.75 knots / 6.5 knots
Range 21,000 nm @ 16 knots
Armament 6x533mm TT fwd + 2x14cm/50 cal. (19 torpedoes).
Max. Depth 100 m (330 feet)
Crew 94 officers and men