Amagi-class battlecruiser

Design for the Amagi class
Class overview
Operators:	Imperial Japanese Navy
Preceded by:	Kongō class
Built:	1920–1922
Planned:	4
Completed:	1 (converted into an aircraft carrier) (Akagi)
Cancelled:	3
Lost:	1
Scrapped:	3
General characteristics
Type:	Battlecruiser
Displacement:	Standard: 41,217 tonnes (40,566 long tons) normal 47,000 tonnes (46,000 long tons) full load
Length:	251.8 m (826 ft)
Beam:	30.8 m (101 ft)
Draft:	9.5 m (31 ft)
Installed power:	131,200 shp (97,800 kW)
Propulsion:	4-shaft Gihon turbines, 19 Kampon boilers
Speed:	30 knots (56 km/h; 35 mph)
Range:	8,000 nmi (15,000 km; 9,200 mi) at 14 knots (26 km/h; 16 mph)
Complement:	1,600
Armament:	10 × 41 cm guns 16 × 14 cm guns 6 × 12 cm AA guns 8 × 61 cm (24 in) torpedo tubes
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) torpedo tubes 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 as part of the Eight-eight fleet. The ships were to be named Amagi, Akagi, Atago, and Takao (initially named ), after the mountains 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 and a modified secondary battery arrangement.

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.