Japanese submarine Ro-34
Ro-34 was a Kaichū-type submarine of the Japanese Navy, in the K6 sub-class. Built by Mitsubishi in Kobe, she was laid down on 25 April 1934, launched on 12 December 1935, and completed on 31 May 1937. She served with Submarine Division 21 out of Sasebo, taking part in prewar training and a scientific cruise in 1939. After periods in and out of reserve, Ro-34 returned to active service in 1940 and served throughout 1941–1943 in the South China Sea, the Netherlands East Indies, off New Guinea, and the Solomon Islands.
Her war patrols began in December 1941. She operated around Cam Ranh Bay and later patrolled the Java Sea and Sunda Strait area, where she fired torpedoes at HMS Encounter in February 1942 but did not sink it. In March 1942 she tangled with a net while near Java and had battery trouble that forced her to surface and fight briefly with her deck gun. She took part in patrols supporting Japanese operations around Java, the Coral Sea, Tulagi, and Port Moresby, and in August 1942 she shelled targets on Guadalcanal from Taivu Point and conducted reconnaissance in the Guadalcanal area.
Ro-34 continued to operate from Rabaul and Truk, assisting midget-submarine efforts and taking part in patrols around the Solomon Islands through late 1942 and into 1943. She endured a battery problem during an overhaul in Sasebo in January 1943 and returned to Rabaul in March 1943 for another patrol. Her eleventh patrol, beginning 2 April 1943 east of the Russell Islands, was to provide weather reports and rescue duties for Operation I-Go.
On the night of 5–7 April 1943, US destroyers O’Bannon and Strong tracked and attacked Ro-34. After a close-range depth-charge attack and gunfire, Ro-34 submerged and was later sunk by Strong. She was officially presumed lost with all hands (66 crew) on 2 May 1943 and was struck from the navy list on 14 July 1943.
Specifications (Kaichū type, K6 sub-class)
- Displacement: 955 tons surfaced, 1,219 tons submerged
- Length: 73 m; Beam: 6.7 m; Draft: 3.25 m
- Propulsion: 2 diesel engines (surface), 2 electric motors (submerged)
- Speed: 19 knots surfaced, 8.25 knots submerged
- Range: 8,000 nautical miles at 12 knots (surface); 90 nautical miles at 3.5 knots (submerged)
- Test depth: 75 m
- Crew: 75
- Armament: 4 bow 533 mm torpedo tubes (10 torpedoes), 1 × 76.2 mm L/40 AA gun, 1 × 13.2 mm MG
This page was last edited on 2 February 2026, at 14:28 (CET).