Imperial Japanese Navy order of battle 1941 explained

Order of battle

Warships

IJN at time of Pearl Harbor Attack in December 1941:

Battleships

• 10 (plus 3 building) (1)
  • 4 Kongō class — converted from battlecruisers. Built in 1913–1915.
    • Kongō — †November, 1944
    • Hiei — †November, 1942
    • Kirishima — †November, 1942
    • Haruna — †July, 1945
  • 2 Fusō class — built 1915-1917
    • Fusō — †October, 1944
    • Yamashiro — †October, 1944
  • 2 Ise class — built 1917-1918
    • Ise — †July, 1945
    • Hyūga — run aground in July, 1945
  • 2 Nagato class — built 1920-1921
    • Nagato
    • Mutsu — †June, 1943
  • 0 Yamato class (3 building (1 converted to aircraft carrier Shinano) and 1 cancelled later in 1941).
    • Yamato — commissioned 1941, † 1945
    • Musashi — commissioned 1942, † 1944
    • The fourth of the class, Hull Number 111 was scrapped in 1942 when only 30% complete, and a proposed fifth hull, Number 797, proposed in the 1942 5th Supplementary Program, was never ordered.

Aircraft carriers

• 6 heavy and 6 light (plus 7 building)(1)
  • Hōshō built in 1922
  • Akagi (2) (ex-battlecruiser converted by 1927) — †1942
  • Kaga (ex-battleship converted in 1928) — †1942
  • Ryūjō completed 1933 — †1942
  • Sōryū — †1942
  • Hiryū — †1942
  • 2 Zuihō class commissioned as aircraft carriers 1940-1941
    • Shōhō - †1942
    • Zuihō - †1944
  • 2 Shōkaku class built 1941
    • Shōkaku — †1944
    • Zuikaku — †1944
  • 3 Taiyō class
    • Taiyō — †1944
    • Chūyō — †1943
    • Unyō — †1944
      • • 2 Hiyō class Hiyō — †1944
    • Jun'yō
  • Shinano (ex-battleship converted in 1942–44) — †1944

(1) Does not include Imperial Japanese Army built aircraft transports.

(2) Amagi — sister ship to Akagi both as a battlecruiser and as a conversion to an aircraft carrier, was destroyed during construction by an earthquake and replaced with the Kaga.

Heavy cruisers

• 18 (plus 1 building) (1)
  • 2 Furutaka built 1926-1927
  • 2 Aoba built 1926-1927
  • 4 Myōkō built 1928-1929
  • 4 Takao built 1932
  • 4 Mogami built 1935-1937(2)
  • 2 Tone built 1941

(1) Ibuki ordered but not laid down(2) Mogamis designated light cruisers but were built to be up-gunned as heavies once the London Naval Treaty was broken.

Light cruisers

• 20 (plus 5 building) (1)
  • 2 Tenryū built 1919
  • 5 Kuma built 1920-1921
  • 1 Yubari built 1923
  • 3 Sendai built 1924-1925
  • 6 Nagara built 1922-1925
  • 3 Katori (1 cancelled) built 1938-1940

(1) 4 Agano and 2 Ōyodo (1 cancelled).

Destroyers

See main article: Japanese World War II destroyers.

• 115 (plus 43 building) (1)
  • 3 Momi-class destroyer (3) built 1920-1922
  • 13 Minekaze-class destroyer built 1920-1922
  • 6 Wakatake-class destroyer built 1922-1923
  • 9 Kamikaze-class destroyer built 1922-1924
  • 12 Mutsuki-class destroyer built 1925-1927
  • 19 Fubuki-class destroyer built 1926-1933 (included Ayanami subclass)
  • 4 Akatsuki-class destroyer built 1932-1933 (subclass of Fubuki class)
  • 6 Hatsuharu-class destroyer built 1933-1935
  • 10 Shiratsuyu-class destroyer built 1936-1937
  • 10 Asashio-class destroyer built 1937-1938
  • 19 Kagerō-class destroyer built 1939
  • 4 Yūgumo-class destroyer built 1941

(1) 27 Yūgumo class and 16 Akizuki-class building(2) Others ships of the Momi-class were re-rated as patrol vessels. Also, note than Momi name was assigned in 1944 to a Matsu-class destroyer ship

Submarines

• 68 Fleet submarines
• 50 Ko-hyoteki-class midget submarines

Others

• 90 patrol ships, gunboats, armed merchant ships, and submarine chasers
• 6 minelayers
  • Itsukushima
• 42 minesweepers
• 55 auxiliaries

Merchant ships

Many under direct navy control as armed merchantmen.

• 1939 - 2,337 with 5,629,845 tons
• World War II construction of 4,250,000 tons
• 2,346 sunk

Aircraft

• Total 1750 first line with 370 trainers
  • 660 Fighters
  • 330 Carrier based strike aircraft
  • 240 Land-based twin engine bombers
  • 520 Seaplanes and flying boats.

Commanders

Imperial Japanese Navy commanders at the time of the Attack on Pearl Harbor:

See also

• List of Japanese Navy ships and war vessels in World War II