Japanese submarine Ro-32


Ro-32, originally named Submarine No. 71, was an Imperial Japanese Navy Kaichu-Type submarine of the Kaichu V subclass. She was in commission from 1924 to 1938, seeing service in the waters of Formosa and Japan, then served as a stationary training hulk during World War II.

Design and description

The submarines of the Kaichu V sub-class were designed for anti-shipping operations and carried more fuel and had greater range and a heavier gun armament than preceding Kaichu-type submarines. They displaced surfaced and submerged. The submarines were long and had a beam of and a draft of. They had a diving depth of.
For surface running, the submarines were powered by two Sulzer diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a electric motor. They could reach on the surface and underwater. On the surface, they had a range of — although the Imperial Japanese Navy officially announced it as — at ; submerged, they had a range of at.
The submarines were armed with four internal bow torpedo tubes and carried a total of eight torpedoes. They were also armed with a single [12 cm/45 3rd Year Type naval gun|] deck gun and one 6.5 mm machine gun.

Construction and commissioning

Ro-32 was laid down as Submarine No. 71 on 24 October 1921 by Kawasaki at Kobe, Japan. Launched on 19 March 1923, she was completed and commissioned on 31 May 1924.

Service history

Upon commissioning, Submarine No. 71 was attached to the Sasebo Naval District, to which she remained attached throughout her active career. On 15 June 1924, she was assigned to both Submarine Division 25 — in which she spent her active career — and the Mako Defense Division headquartered at Mako in the Pescadores Islands. She was renamed Ro-32 on 1 November 1924. On 1 December 1926, she was reassigned to the Sasebo Defense Division, headquartered at Sasebo, Japan. Her service in the Sasebo Defense Division ended on 15 November 1934, after which she served as a unit of Submarine Division 25 in the Sasebo Naval District.
Ro-32 was decommissioned and placed in the Fourth Reserve on 15 December 1938. The Japanese struck her from the Navy list on 1 April 1942, and that day she became a stationary training hulk at the submarine school at Ōtake, Japan. She was scrapped ca. August 1945.
During World War II, the United States Coast Guard cutter, the Coast Guard-crewed United States Navy patrol vessel, and a Royal Canadian Air Force Bristol Bolingbroke maritime patrol aircraft of No. 115 Squadron shared credit for the sinking of a submarine in the Pacific Ocean off Southeast Alaska at on 9 July 1942, and in 1947 the Joint Army-Navy Assessment Committee identified the sunken submarine as Ro-32. In 1967, the U.S. Navy retracted that finding after determining that Ro-32 had been inactive in Japan at the time of the sinking and had remained afloat through the end of World War II.