Wartime lessons in the modified Taiho design

The five projected ships belonged to a major Japanese construction program and were enlarged developments of Taiho, rather than the lighter emergency-built Unryu class. A slender hull, bulbous bow, and Taiho machinery sought high speed despite the added displacement. Direct magazine-to-flight-deck elevators kept bomb and torpedo handling out of the hangars, addressing a danger exposed at Midway. Revised aviation-fuel arrangements, firefighting gear, and anti-explosion measures responded to the petrol-vapor catastrophe that destroyed Taiho after a torpedo hit. The two superimposed hangars sat beneath an armored flight deck, with a second armored deck below the lower hangar to protect fuel tanks and magazines. Heavier anti-aircraft armament and improved underwater protection carried further wartime lessons into the design.