The Cruiser submarine Type-A (巡潜甲型潜水艦, Junsen Kō-gata sensuikan) was a class of submarine in the Imperial Japanese Navy (IJN), which served during the Second World War. The Type-A submarines were built to take a role of the command ships for submarine squadrons. For this reason they had equipment for a headquarters, better radio facilities and a floatplane.
Class variants
The Type-A submarines were divided into four classes:
Sank Greek merchant ship George S. Livanos 20-07-1942 Sank USS Coast Farmer 21-07-1942 Sank USS William Dawes 22-07-1942 Damaged HMAS Hobart 20-07-1943 Damaged USS Matthew Lyon 11-08-1943
Lost in an accident or sunk by a mine near Funafuti January 1944.
Type-A Mod.1 (I-12 class)
Project number S35B. Five boats were planned under the Maru Tsui Programme (Boat # 620 - 621) and the Kai-Maru 5 Programme (Boat # 5091 - 5093). They were equipped with less powerful diesel engines which shortened the time needed to build them. Only one boat, I-12, was completed to the original design. The I-13 and the later boats were converted to a new submarine class (I-13 class), because the number of I-400 class boats was reduced.
(Left to right) USS Proteus, I-400, I-401 and I-14 on 29 August 1945 at Yokosuka
Project number S35C. Four boats were planned under the Maru Tsui Programme (Boat # 621) and the Kai-Maru 5 Programme (Boat # 5091 - 5093). However, four boats were converted to new submarine class (I-13 class), because a number of submarines of the I-400 class were cancelled. They had a large hangar and were equipped with bulges to be able to operate 2 × special Aichi M6A1 Seiran attack bombers. The headquarters institutions were removed.
70% complete; Sunk by a typhoon on 18-09-1945; later salvaged and scrapped.
V21 Type
Project number S48. Three boats were planned under the Kai-Maru 5 Programme. However, all boats were cancelled in late 1943, because the IJN turned its attention to the construction of Type E submarine [ja] (戊型潜水艦, Bo-gata sensuikan) in 1945.
Rekishi Gunzō, History of Pacific War Vol.63 "Documents of IJN submarines and USN submarines", Gakken (Japan), January 2008, ISBN978-4-05-605004-2
Rekishi Gunzō, History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", Gakken (Japan), March 2005, ISBN4-05-603890-2
Model Art Extra No.537, Drawings of Imperial Japanese Naval Vessels Part-3, Model Art Co. Ltd. (Japan), May 1999, Book code 08734-5
The Maru Special, Japanese Naval Vessels No.13, "Japanese submarines I-13 class and I-400 class", Ushio Shobō (Japan), July 1977, Book code 8343-7
The Maru Special, Japanese Naval Vessels No.31, "Japanese Submarines I", Ushio Shobō (Japan), September 1979, Book code 68343-31
Senshi Sōsho Vol.88 Naval armaments and war preparation (2), "And after the outbreak of war", Asagumo Simbun (Japan), October 1975
S: Single ship of classC: Converted to ship typeL: Officially classed as light cruisers until 1939 refitsI: Incomplete until the end of the warX: Cancelled
Imperial Japanese Navy
