Tosa-class battleship

Scale model of Kaga as originally designed
Class overview
Name:	Tosa class
Operators:	Imperial Japanese Navy
Preceded by:	Nagato class
Succeeded by:	Kii class
Built:	1920–1922
Planned:	2
Completed:	1; converted to an aircraft carrier (Kaga)
Cancelled:	1
General characteristics
Type:	Dreadnought battleship
Displacement:	39,900 t (39,300 long tons) (normal) 44,200 t (43,500 long tons) (full load)
Length:	231.7 m (760 ft 2 in)
Beam:	30.5 m (100 ft 1 in)
Draft:	9.4 m (30 ft 10 in)
Installed power:	91,000 shp (68,000 kW) 12 × water-tube boilers
Propulsion:	4 × shafts 4 × geared Brown-Curtis steam turbines
Speed:	26.5 knots (49.1 km/h; 30.5 mph)
Range:	5,500 nmi (10,200 km; 6,300 mi) at 16 knots (30 km/h; 18 mph)
Armament:	5 × twin 41 cm guns 20 × single 14 cm guns 4 × single 76 mm AA guns 8 × 61 cm (24 in) torpedo tubes
Armor:	Waterline belt: 280 mm (11.0 in) Deck: 102 mm (4.0 in) Barbettes: 305–229 mm (12.0–9.0 in) Conning tower: 356 mm (14.0 in)

The Tosa-class battleships (土佐型戦艦^?, Tosa-gata Senkan) were two dreadnoughts ordered as part of the "Eight-Eight" fleet for the Imperial Japanese Navy (IJN) during the early 1920s. The ships were larger versions of the preceding Nagato class, and carried an additional 41-centimeter (16.1 in) twin-gun turret. The design for the class served as a basis for the Amagi-class battlecruisers.

Both ships were launched in late 1921, but the first ship, Tosa, was cancelled in accordance with the terms of the Washington Naval Treaty before it could be completed, and was used in experiments testing the effectiveness of its armor scheme before being scuttled in the Bungo Channel. The hull of the second ship, Kaga, was converted into an aircraft carrier of the same name. The carrier supported Japanese troops in China during the Second Sino-Japanese War of the late 1930s, and took part in the attack on Pearl Harbor on 7 December 1941 and the invasion of Rabaul in the Southwest Pacific in January 1942. The following month her aircraft participated in a combined carrier airstrike on Darwin, Australia, during the Dutch East Indies campaign. She was sunk during the Battle of Midway in 1942.