Japanese submarine Ro-55 (1921)

The first Ro-55, originally named Submarine No. 29, was an Imperial Japanese Navy Type L submarine of the L2 subclass. Except for a few months in 1926, she was in commission from 1921 to 1938.

History
Japan
NameSubmarine No. 29
BuilderMitsubishi, Kobe, Japan
Laid down30 March 1920
Launched10 February 1921
Completed15 November 1921
Commissioned15 November 1921
RenamedRo-55 on 1 November 1924
Decommissioned1 April 1926
Recommissioned1 August 1926
Decommissioned15 December 1938
Stricken1 April 1940
General characteristics
Class and typeJapanese Type L submarine (L2 subclass)
Displacement
  • 907 tonnes (893 long tons) surfaced
  • 1,093 tonnes (1,075.3 long tons) submerged
Length70.59 m (231 ft 7 in) overall
Beam7.16 m (23 ft 6 in)
Draft3.94 m (12 ft 11 in)
Installed power
Propulsion
Speed
  • 17.3 knots (32.0 km/h; 19.9 mph) surfaced
  • 10.4 knots (19.3 km/h; 12.0 mph) submerged
Range
  • 5,500 nmi (10,200 km; 6,300 mi) at 10 knots (19 km/h; 12 mph) surfaced
  • 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth60 m (197 ft)
Crew45
Armament

Design and description edit

The submarines of the Type L2 sub-class were close copies of the British L-class submarine built under license in Japan. They differed from the preceding L1 subclass in the deletion of the two broadside-firing torpedo tubes and the two torpedoes for them, the use of domestically produced diesel engines and batteries, and a different battery arrangement. They displaced 907 tonnes (893 long tons) surfaced and 1,093 tonnes (1,075.3 long tons) submerged. The submarines were 70.59 meters (231 ft 7 in) long and had a beam of 7.16 meters (23 ft 6 in) and a draft of 3.94 meters (12 ft 11 in). They had a diving depth of 60 meters (197 ft).

For surface running, the submarines were powered by two 1,200-brake-horsepower (895 kW) Vickers diesel engines, each driving one propeller shaft. When submerged, each propeller was driven by an 800-shaft-horsepower (597 kW) electric motor. They could reach 17.3 knots (32.0 km/h; 19.9 mph) on the surface and 10.4 knots (19.3 km/h; 12.0 mph) underwater. On the surface, they had a range of 5,500 nautical miles (10,200 km; 6,300 mi) at 10 knots (19 km/h; 12 mph); submerged, they had a range of 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph).

The submarines were armed with four internal 450 mm (18 in) torpedo tubes, all in the bow, and carried a total of eight Type 44 torpedoes. They were also armed with a single 76.2 mm (3 in) deck gun.

Construction and commissioning edit

Ro-55 was laid down as Submarine No. 29 on 30 March 1920 by Mitsubishi at Kobe, Japan.[1] Launched on 10 February 1921,[1] she was completed and commissioned on 15 November 1921.[1]

Service history edit

Upon commissioning, Submarine No. 29 was attached to the Yokosuka Naval District.[1] On 1 December 1921, she was reassigned to Submarine Division 4 in Submarine Squadron 1 in the 1st Fleet.[1] She was renamed Ro-55 on 1 November 1924.[1] Submarine Division 4 was reattached to the Yokosuka Naval District on 1 December 1925, and Ro-55 and was assigned that day to the Yokosuka Defense Division.[1] She was decommissioned and placed in reserve on 1 April 1926.[1]

Ro-55 was recommissioned on 1 August 1926, and was assigned to the Yokosuka Defense Division that day, serving in that duty until 1 December 1927.[1] She later served in the Yokosuka Defense Division again from 30 November 1929 to 15 November 1934.[1]

Ro-55 was decommissioned and placed in the Fourth Reserve in the Yokosuka Naval District on 15 December 1938.[1] The Japanese struck her from the Navy list on 1 April 1940.[1]

Notes edit

  1. ^ a b c d e f g h i j k l "RO-55 ex No-29". iijnsubsite.info. 2018. Retrieved 11 October 2020.

Bibliography edit

  • "Rekishi Gunzō"., History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", Gakken (Japan), March 2005, ISBN 4-05-603890-2
  • The Maru Special, Japanese Naval Vessels No.43 Japanese Submarines III, Ushio Shobō (Japan), September 1980, Book code 68343-44
  • The Maru Special, Japanese Naval Vessels No.132 Japanese Submarines I "Revised edition", Ushio Shobō (Japan), February 1988, Book code 68344-36
  • The Maru Special, Japanese Naval Vessels No.133 Japanese Submarines II "Revised edition", Ushio Shobō (Japan), March 1988, Book code 68344-37