Imperial Japanese Navy of World War II

Main article: Imperial Japanese Navy of World War II

Imperial Japanese Navy warships in World War II
	Number of units
Battleships	11
Fleet carriers	21
Light carriers	4
Cruisers	45
Destroyers	141
Submarines	171

The Imperial Japanese Navy of World War II was the second most powerful navy in the Pacific War in World War II. It was the third largest navy in the world. During the first years of the war the Imperial Japanese Navy dominated the Western Pacific. However, after a series of defeats it lost control of the Western Pacific and collapsed by the end of the war. It was controlled by the Imperial Japanese Navy General Staff and the Navy Ministry. The naval air service was one of the most potent air forces in the world before its destruction in World War II.

Personnel Strength

Imperial Japanese Navy ranks.

• December 1941 — 291,359 including 1,500 pilots
• July 1945 — 1,663,223

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

(1)4 Yamato class (3 building(1 Shinano converted to an aircraft carrier) and 1 cancelled later in 1941)

• Yamato — commissioned 1941, † 1945
• Musashi — commissioned 1942, † 1944

Hull Number 111 was scrapped in 1943 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
  • 2 Sōryū class built 1937-1939
    • Sōryū — †1942
    • Hiryū — †1942
  • 2 Shoho class commissioned as aircraft carriers 1940-1941
    • Shoho - †1942
    • Zuiho - †1944
  • 2 Shōkaku class built 1941-still on trials and workup.
    • Shōkaku — †1944
    • Zuikaku — †1944
  • 2 Hiyō class
    • Hiyō — †1944
    • Jun'yō

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

(2)Amagi — sistership 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 (by class)

• 20 (plus 9 building)(1) (This is not consistent with the following list.)
  • 2 Tenryū built 1919
  • 5 Kuma built 1920-1921
  • 1 Yubari built 1923
  • 3 Sendai built 1924-1925
  • 6 Nagara built 1922-1925
  • 4 Agano built 1942-1943

(1)3 Katori (1 cancelled), 4 Agano and 2 Ōyodo

Destroyers

Main article: Japanese World War II destroyers

• 108 (plus 43 building)(1)
  • 3 Momi Class Destroyer (2) built 1920-1922
  • 13 Minekaze Class Destroyer built 1920-1922
  • 7 Wakatake Class Destroyer built 1922-1923
  • 4 Kamikaze Class Destroyer built 1922-1924
  • 12 Mutsuki Class Destroyer built 1925-1927
  • 20 Fubuki Class Destroyer built 1926-1933
  • 4 Akatsuki Class Destroyer built 1932-1933
  • 6 Hatsuharu Class Destroyer built 1933-1935
  • 10 Shiratsuyu Class Destroyer built 1936-1937
  • 10 Asashio Class Destroyer built 1937-1938
  • 18 Kagerō Class Destroyer built 1939
  • 1 Yūgumo Class Destroyer built 1941

(1)27 Yugumo class and 16 Akatsuki class building (2)Others of class re-rated as patrol vessels (3)2 others of class converted to patrol vessels.

Submarines

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

Others

• 90 patrol ships, gunboats, armed merchantships, 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:

• 

  Admiral Osami Nagano (Chief of the Imperial Japanese Navy General Staff)

• 

  Admiral Isoroku Yamamoto (Commander-in-chief of the Combined Fleet)

• 

  Rear Admiral Matome Ugaki (Chief-of-Staff of the Combined Fleet)

• 

  Vice Admiral Chūichi Nagumo (Commander-in-Chief of the First Air Fleet)

• 

  Vice Admiral Nobutake Kondō (2nd Fleet)

• 

  Vice Admiral Ibō Takahashi (3rd Fleet)

• 

  Vice Admiral Inoue Shigeyoshi (4th Fleet)

See also

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