Japanese submarine I 55 (1943)

Design and description

The Type C3 submarines were derived from the earlier C2 sub-class although with fewer torpedo tubes, an additional deck gun, and less-powerful engines to extend their range. They displaced 2,605 tonnes (2,564 long tons) surfaced and 3,702 tonnes (3,644 long tons) submerged. The submarines were 108.7 meters (356 ft 8 in) long, had a beam of 9.3 meters (30 ft 6 in) and a draft of 5.1 meters (16 ft 9 in). They had a diving depth of 100 meters (330 ft).

For surface running, the boats were powered by two 2,350-brake-horsepower (1,752 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 600-horsepower (447 kW) electric motor. They could reach 17.7 knots (32.8 km/h; 20.4 mph) on the surface and 6.5 knots (12.0 km/h; 7.5 mph) underwater. On the surface, the C3s had a range of 27,000 nautical miles (50,000 km; 31,000 mi) at 12 knots (22 km/h; 14 mph); submerged, they had a range of 105 nmi (194 km; 121 mi) at 3 knots (5.6 km/h; 3.5 mph).

The boats were armed with six internal bow 53.3 cm (21.0 in) torpedo tubes and carried a total of 19 torpedoes. They were also armed with two 14 cm (5.5 in) deck guns and one twin mount for 25 mm (1 in) Type 96 anti-aircraft guns.

Construction and career

Assigned to the defense of the Marianas, during a mission to rescue staff of the 1st Air Fleet on Tinian, she was presumably found and sunk by the USS Gilmer and USS William C. Miller on 14 July 1944, though some sources claim this sinking was actually the Ro-48.

See also USS Wyman and USS Reynolds references to the sinking of this submarine in which Wyman claims credit for this sinking on 28 July 1944.