Japanese aircraft carrier Akagi

Akagi conducting flight operations in April 1942
Class overview
Operators:	Imperial Japanese Navy
Preceded by:	Hōshō
Succeeded by:	Kaga
Built:	1920–27
In service:	1927–42
In commission:	1927–42
Completed:	1
Lost:	1
History
Empire of Japan
Name:	Akagi
Namesake:	Mount Akagi
Ordered:	1920
Builder:	Kure Naval Arsenal
Cost:	¥53 million ($36.45 million)
Laid down:	6 December 1920
Launched:	22 April 1925
Commissioned:	25 March 1927
Reclassified:	21 November 1923 as an aircraft carrier
Refit:	24 October 1935 – 31 August 1938
Struck:	25 September 1942
Fate:	Damaged by U.S. air attack at the Battle of Midway and scuttled by Japanese destroyers on 5 June 1942
General characteristics (after 1938 modernization)
Class and type:	none
Type:	Aircraft carrier
Displacement:	36,500 long tons (37,100 t) (standard) 41,300 long tons (42,000 t) (deep load)
Length:	260.67 m (855 ft 3 in)
Beam:	31.32 m (102 ft 9 in)
Draught:	8.71 m (28 ft 7 in)
Installed power:	133,000 shp (99,000 kW) 19 Kampon water-tube boilers
Propulsion:	4 shafts 4 Kampon geared steam turbines
Speed:	31.5 knots (58.3 km/h; 36.2 mph)
Range:	10,000 nmi (19,000 km; 12,000 mi) at 16 knots (30 km/h; 18 mph)
Complement:	1,630
Armament:	6 × single 20 cm (7.9 in) guns 6 × twin AA 12 cm (4.7 in) AA guns 14 × twin 25 mm (1 in) AA guns
Armor:	Belt: 152 mm (6.0 in) Deck: 79 mm (3.1 in)
Aircraft carried:	66 (+25 reserve) 21 Mitsubishi A6M Zero 18 Aichi D3A 27 Nakajima B5N (7 Dec 1941)
Service record
Part of:	First Air Fleet (Kido Butai)
Commanders:	Isoroku Yamamoto (1928–29) Ryūnosuke Kusaka (1939–40) Kiichi Hasegawa (1941–42) Taijiro Aoki (1942)
Operations:	Second Sino-Japanese War World War II, Pacific War: Attack on Pearl Harbor Invasion of Rabaul Bombing of Darwin Invasion of Java Indian Ocean raid Battle of Midway

Akagi (Japanese: 赤城 "Red Castle") was an aircraft carrier built for the Imperial Japanese Navy (IJN), named after Mount Akagi in present-day Gunma Prefecture. Though she was laid down as an Amagi-class battlecruiser, Akagi was converted to an aircraft carrier while still under construction to comply with the terms of the Washington Naval Treaty. The ship was rebuilt from 1935 to 1938 with her original three flight decks consolidated into a single enlarged flight deck and an island superstructure. The second Japanese aircraft carrier to enter service, and the first large or "fleet" carrier, Akagi figured prominently in the development of the IJN's new carrier striking force doctrine that grouped carriers together, concentrating their air power. This doctrine enabled Japan to attain its strategic goals during the early stages of the Pacific War from December 1941 until mid-1942.

Akagi's aircraft served in the Second Sino-Japanese War in the late 1930s. Upon the formation of the First Air Fleet or Kido Butai (Striking Force) in early 1941, she became its flagship, and remained so for the duration of her service. With other fleet carriers, she took part in the Attack on Pearl Harbor in December 1941 and the invasion of Rabaul in the Southwest Pacific in January 1942. The following month, her aircraft bombed Darwin, Australia, and assisted in the conquest of the Dutch East Indies. In March and April 1942, Akagi's aircraft helped sink a British heavy cruiser and an Australian destroyer in the Indian Ocean Raid.