Amagi-class battlecruiser

Line drawing of this type of vessel; the ship had a long hull, two tall masts, five gun turrets, and two large funnels.
Design for the Amagi class
Class overview
Builders
OperatorsImperial Japanese Navy
Preceded byKongō class
Succeeded byDesign B-65
Built1920–1922
Planned4
Completed1 (converted into an aircraft carrier)
Cancelled3
Lost1
Scrapped3
General characteristics
TypeBattlecruiser
Displacement
  • 41,217 t (40,566 long tons) (normal)
  • 47,000 t (46,260 long tons) (full load)
Length251.8 m (826 ft)
Beam30.8 m (101 ft)
Draft9.5 m (31 ft)
Installed power
Propulsion4 shafts; 4 steam turbines
Speed30 knots (56 km/h; 35 mph)
Range8,000 nmi (15,000 km; 9,200 mi) at 14 knots (26 km/h; 16 mph)
Complement1,600
Armament
Armor
  • Belt: 250 mm (9.8 in)
  • Deck: 95 mm (3.7 in)
  • Conning Tower: 75–360 mm (3.0–14.2 in)
  • Torpedo bulkheads: 73 mm (2.9 in)
  • Barbettes: 230–280 mm (9.1–11.0 in)

The Amagi class (天城型, Amagi-gata) was a series of four battlecruisers planned for the Imperial Japanese Navy (IJN) as part of the Eight-eight fleet in the early 1920s. The ships were to be named Amagi, Akagi, Atago, and Takao. The Amagi design was essentially a lengthened version of the Tosa-class battleship, but with a thinner armored belt and deck, a more powerful propulsion system, and a modified secondary armament arrangement. They were to have carried the same main battery of ten 41 cm (16.1 in) guns and been capable of a top speed of 30 knots (56 km/h; 35 mph).

Limitations imposed by the 1922 Washington Naval Treaty prevented the class from being completed as designed. However, the treaty had a limited allowance for hulls already under construction to be converted into aircraft carriers. Amagi and Akagi were both intended for conversion, but an earthquake damaged the hull of Amagi so extensively that the ship was scrapped. Akagi was reconstructed as an aircraft carrier and served with distinction as part of the Kido Butai during the Second World War, participating in the Japanese attack on Pearl Harbor before being sunk at the Battle of Midway.