Japanese submarine Ro-20

History
Japan
Name	Submarine No. 38
Builder	Yokosuka Naval Arsenal, Yokosuka, Japan
Laid down	28 July 1919
Launched	26 October 1920
Completed	1 February 1922
Commissioned	1 February 1922
Renamed	Ro-20 on 1 November 1924
Stricken	1 April 1934
Fate	Sold 6 July 1935; Scuttled as artificial reef ca. 1935;
General characteristics
Class and type	Kaichū type submarine (K3 subclass)
Displacement	752 tonnes (740 long tons) surfaced; 1,013 tonnes (997 long tons) submerged;
Length	70.10 m (230 ft 0 in) overall
Beam	6.12 m (20 ft 1 in)
Draft	3.70 m (12 ft 2 in)
Installed power	2,900 bhp (2,200 kW) (diesel); 1,200 hp (890 kW) (electric motor);
Propulsion	Diesel-electric; 2 × Sulzer Mark II diesel engine, 75 tons fuel; 2 × electric motor; 2 x shafts;
Speed	16.5 knots (30.6 km/h; 19.0 mph) surfaced; 8.5 knots (15.7 km/h; 9.8 mph) submerged;
Range	6,000 nmi (11,000 km; 6,900 mi) at 10 knots (19 km/h; 12 mph) surfaced; 85 nmi (157 km; 98 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged;
Test depth	45.7 m (150 ft)
Crew	46
Armament	6 × 450 mm (18 in) torpedo tubes (4 x bow, 2 x external on upper deck); 10 x Type 44 torpedoes; 1 × 76.2 mm (3.00 in) gun;

Ro-20, originally named Submarine No. 38, was an Imperial Japanese Navy Kaichū-Type submarine of the Kaichū III subclass. She was commissioned in 1922 and operated in the waters of Japan. She was stricken in 1934.

Design and description[edit]

The submarines of the Kaichu III sub-class were a slightly improved version of the preceding Kaichu II subclass, the man difference being an increase in diving depth from 30 to 45.7 meters (98 to 150 ft).^[1] They displaced 752 tonnes (740 long tons) surfaced and 1,013 tonnes (997 long tons) submerged. The submarines were 70.10 meters (230 ft 0 in) long and had a beam of 6.12 meters (20 ft 1 in) and a draft of 3.70 meters (12 ft 2 in).

For surface running, the submarines were powered by two 1,450-brake-horsepower (1,081 kW) Sulzer Mark II diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 600-horsepower (447 kW) electric motor. They could reach 16.5 knots (31 km/h; 19 mph) on the surface and 8.5 knots (15.7 km/h; 9.8 mph) underwater. On the surface, they had a range of 6,000 nautical miles (11,000 km; 6,900 mi) at 10 knots (19 km/h; 12 mph); submerged, they had a range of 85 nmi (157 km; 98 mi) at 4 knots (7.4 km/h; 4.6 mph).

The submarines were armed with six 450 mm (18 in) torpedo tubes, four internal tubes in the bow and two external tubes mounted on the upper deck, and carried a total of ten Type 44 torpedoes. They were also armed with a single 76.2 mm (3.00 in) deck gun mounted aft of the conning tower.^[1]

Construction and commissioning[edit]

Ro-20 was laid down as Submarine No. 38 on 28 July 1919 by the Yokosuka Naval Arsenal at Yokosuka, Japan.^[2] Launched on 26 October 1920,^[2] she was completed and commissioned on 1 February 1922.^[2]

Service history[edit]

Upon commissioning, Submarine No. 38 was attached to the Yokosuka Naval District, to which she remained attached throughout her career.^[2] On 6 February 1922, she was assigned to Submarine Division 5 and to the Ominato Defense Division,^[2] and on 1 November 1924 she was renamed Ro-20.^[2] On 1 November 1925, Submarine Division 5 was reassigned to the Yokosuka Defense Division,^[2] then directly to the Yokosuka Naval District on 1 December 1926, and then to the Yokosuka Defense Division again on 10 January 1927.^[2]

Ro-20 was stricken from the Navy list on 1 April 1934.^[2] Her engines were removed at Uraga Shipyard, and on 6 July 1935 she was sold to the Fisheries Association of Miura District in Kanagawa Prefecture for use as an artificial reef. She subsequently was scuttled to serve as a breeding ground for fish and fishing reef.

Notes[edit]

^ ^a ^b Gray, Randal, ed., Conway′s All the World′s Fighting Ships 1906–1921, Annapolis, Maryland: Naval Institute Press, 1985, ISBN 0 87021 907 3, p. 248.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ "RO-20 ex No-38". iijnsubsite.info. 2018. Retrieved 14 October 2020.

References[edit]

"Rekishi Gunzō"., History of Pacific War Vol.17 I-Gō Submarines, Gakken (Japan), January 1998, ISBN 4-05-601767-0
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
The Maru Special, Japanese Naval Vessels No.135 Japanese Submarines IV, Ushio Shobō (Japan), May 1988, Book code 68344-39

[gray-1] Gray, Randal, ed., Conway′s All the World′s Fighting Ships 1906–1921, Annapolis, Maryland: Naval Institute Press, 1985, ISBN 0 87021 907 3, p. 248.

[ijnsubsiteRo20-2] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ "RO-20 ex No-38". iijnsubsite.info. 2018. Retrieved 14 October 2020.

[1]

[2]

v t e Kaichū type submarine
Ro-11-class (Type K1)	Ro-11 Ro-12
Ro-13-class (Type K2)	Ro-13 Ro-14 Ro-15
Ro-16-class (Type K3)	Ro-16 Ro-17 Ro-18 Ro-19 Ro-20 Ro-21 Ro-22 Ro-23 Ro-24 Ro-25
Ro-26-class (Type K4)	Ro-26 Ro-27 Ro-28
Ro-29-class (Toku-Chū/Type K5)	Ro-29 Ro-30 Ro-31 Ro-32
Ro-33-class (Type K6)	Ro-33 Ro-34
Ro-35-class (Sen-Chū/Type K7)	Ro-35 Ro-36 Ro-37 Ro-38 Ro-39 Ro-40 Ro-41 Ro-42 Ro-43 Ro-44 Ro-45 Ro-46 Ro-47 Ro-48 Ro-49 Ro-50 Ro-55 Ro-56
Preceded by: Type L submarine Followed by: Ko type submarine Imperial Japanese Navy submarines

v t e Shipwrecks and maritime incidents in 1935
Shipwrecks	2 Jan: Lexington 24 Jan: Mohawk 25 Jan: Rondo 20 Feb: Vila 24 Apr: HMAS Geranium, HMAS Mallow 25 Jun: USS Marcus 26 Jun: USS Sloat 9 Jul: Maheno 31 Jul: Verdi 1 Aug: HMAS Marguerite 3 Aug: Princess Ena 17 Sep: HMS L52 Unknown date: Chikuma, Ro-20, Ro-21, Ro-28
Other incidents	6 Jan: Havana 25 Jan: Dumana January (unknown date): Ruth Kellogg 2 Mar: Pommern 10 Apr: Aquitania 11 Apr: Letitia 12 May: USS Sicard 21 May: Naïade 25 May: I-24 May (unknown date): Ruth Kellogg 12 Jun: HMS Hastings 13 Jul: L'Espoir 1 Aug: Akatsuki, I-6 16 Aug: Letitia 4 Sep Prince Rupert 5 Sep: Doric 29 Sep: Rotterdam 17 Oct: Noemijulia Unknown date: Giulio Cesare
1934 1936