History of the Akagi Class

In 1918, the Japanese approved designs for the first ships of their "8-8" plan, so called because it would have provided Japan with 8 modern battleships and 8 battlecruisers. The Amagi Class battlecruisers (Junyo Senkan) were a design equivalent to the British Hood or the American Lexington Class, being similar in size, protection, and armament.
The ships had a physical appearance similar to the Nagato Class battleships, but with an extra twin turret aft. A six-legged mast, of the type later retrofitted to existing battleships and known a 'pagodas', would have been fitted. The side armor would have been inclined as in the British Hood, the second such Japanese design with inclined armor, the Tosa Class battleships being the first. The four following ships of the Owari Class would have been nearly identical, with slightly increased side protection, but would have carried the 'fast battleship' ( Kosoku Senkan) designation.
The torpedo armament was to have been rigidly mounted on the battery deck, two pairs laterally offset to each other on the quarterdeck.
The four Amagi Class battlecruisers and the two preceding Tosa Class battleships were all cancelled on February 5, 1922, under the terms of the Washington Treaty. Amagi and Akagi were approximately 40% completed, so they were selected for conversion in to aircraft carriers. On September 1, 1923, the Amagi was damaged beyond repair in an earthquake and was broken up on the slipway. The Tosa Class battleship Kaga was selected as her replacement for conversion.
Akagi was completed as a carrier in 1927. She had an abbreviated main flight deck plus two flying off platforms on the bow, and carried no island structure. This arrangement soon became unsatisfactory, as the latest aircraft were too large to use the bow platforms. Akagi was rebuilt 1936 to 1938 as a full flight deck carrier with a small island on the port side. She was sunk at the battle of Midway.

Amagi:
Laid down
16 Dec 1920
Conversion to carrier started but hull damaged by earchquake 1 Sep 1923, broken up
Akagi:
Laid down 6 Dec 1920
Launched7 Apr 1925
Commissioned 16 Nov 1927
Atago
Laid down
22 Nov 1921
Broken up before completion
Takao:
Laid down 19 Dec 1921
Broken up before completion
Builders:
Amagi- Yokosuka
Akagi- Kure
Atago
- Kawasaki
Takao- Mitsubishi
Complement
Approx 1,600
The information that follows is for the 1918 design for the battlecruisers,
not for the ships converted into carriers
Displacement
40,000 tons standard
41,217 tons loaded
Dimensions
770'@WL x 101'
Draught
31'at full load
Main guns
10 x 16/45" (5 x 2)
Secondary guns
16 x 5.5/50" (16 x 1)
AA Guns
4 x 4.7/45"
Torpedo tubes
8 x 21" above water
Armour Belt
10"inclined
Turret Armor
14" face
Deck Armor
6.6"
Conning Tower Armor
14"
Boilers
19 Kampon
8 coal, 11 oil
Turbines
4 x Gijutsu-Hombu geared turbines
Power output
131,200 shp
Shafts
4
Speed
30 kts
Range
8000 NM @14 knots
Fuel
2500 tons coal
3900 tons oil


Akagi
Work suspended 5 February 1922
Work resumed (as carrier conversion) 19 November 1923
Ship floated in drydock April 7, 1925.
Towed out of drydock April 22, 1925
Official launch date April 22, 1925
Conversion completed March 27, 1927 by Sasebo Kaigun Kosho
Rebuilt April 1936 to September 1938

WWII Service:
China, Pearl Harbor, Rabaul, Darwin, Java, Ceylon, Midway

June 4, 1942, severely damaged by US planed from the Yorktown and Enterprise at the Battle of Midway. After uncontrollable fires burned for 18 hours and propulsion was lost, the ship was sunk by torpedoes from Japanese destroyers at 30-30 N, 178-40 W.
263 men killed.
Removed from Navy list September 25, 1942


BACK