I-121 (as I-21) in 1930.
|Name:||I-121 class submarine|
|Operators:||Imperial Japanese Navy|
|Displacement:||1,142 long tons (1,160 t) surfaced
1,768 long tons (1,796 t) submerged
|Length:||85.20 m (279 ft 6 in) overall|
|Beam:||7.52 m (24 ft 8 in)|
|Draft:||4.42 m (14 ft 6 in)|
|Propulsion:||2 × Rauschenbach Mk.1 diesels
2,400 bhp surfaced
1,100 shp submerged
|Speed:||14.9 knots (27.6 km/h) surfaced
6.5 knots (12.0 km/h) submerged
|Range:||10,500 nmi (19,400 km) at 8 knots (15 km/h) surfaced
40 nmi (74 km) at 4.5 knots (8.3 km/h) submerged
|Test depth:||75 m (246 ft)|
|Armament:||• 2 × 533 mm (21 in) torpedo tubes
• 12 × 6th Year Type torpedoes
• 1 × 14 cm/40 11th Year Type naval gun
• 42 × naval mines
The I-121-class submarine (伊百二十一型潜水艦 I-hyaku-ni-jū-ichi-gata sensuikan?) was a class of submarine in the Imperial Japanese Navy (IJN), serving from the 1920s to the Second World War. The IJN classed it as a Kiraisen type submarine (機雷潜型潜水艦 Kiraisen-gata sensuikan?). The type name, was shortened to Kirai Fusetsu Sensuikan (機雷敷設潜水艦 Minelaying submarine?).
The Empire of Japan received six U-boats as a reparation payment after World War I. The IJN copied U-125 and designed the I-21 class (later renamed I-121 class) minelaying submarine. Six boats were ordered, of which four were completed, two were cancelled. All boats were built in the Kawasaki Yard at Kobe.
When World War II began, they were considered obsolete and used as minelayers and supply submarines for flying boats in the Pacific. Three boats of the class were lost in action. The I-121 survived the war and was sunk as a target post war.
Boats in class
(ex-Submarine No. 48)
|20 October 1924 as Submarine No. 48||30 March 1926 as I-21||31 March 1927||Sank Dutch merchant ship Bantam on 18 January 1942||Renamed I-21 on 1 November 1924; renamed I-121 on 1 June 1938. Decommissioned on 30 November 1945. Sunk as a target off Maizuru on 30 April 1946 by the United States Navy.|
(ex-Submarine No. 49)
|28 February 1925 as I-22||8 November 1926||28 October 1927||Renamed I-122 on 1 June 1938. Sunk by USS Skate at Noto Peninsula on 9 June 1945.|
(ex-Submarine No. 50)
|12 June 1925 as I-23||19 March 1927||28 April 1928||Renamed I-123 on 1 June 1938. Sunk by USS Gamble at Indispensable Strait on 29 August 1942.|
(ex-Submarine No. 52)
|17 April 1926 as I-24||12 December 1927||10 December 1928||Sank RMS Hareldawins on 10 December 1941||Renamed I-124 on 1 June 1938. Sunk by HMAS Deloraine, HMAS Katoomba and HMAS Lithgow at Port Darwin on 20 January 1942.|
|Submarine No. 53?
Submarine No. 63?
|Cancelled in 1924.|
- Campbell, John Naval Weapons of World War Two ISBN 0-87021-459-4 p.191
- 伊号第121潜水艦 (I-Gō Dai-121 Sensuikan?). The same shall apply hereinafter.
- Submarine I-121: Tabular Record of Movement
- "Rekishi Gunzō"., Gakken (Japan)
- The Maru Special, Ushio Shobō (Japan)
- Japanese Naval Vessels No. 43, Japanese Submarines III, September 1980
- Japanese Naval Vessels No. 132, Japanese Submarines I (New edition), February 1988
- Japanese Naval Vessels No. 133, Japanese Submarines II (New edition), March 1988