Kaga was an aircraft carrier built for the Imperial Japanese Navy. Originally intended to be one of two Tosa-class battleships, Kaga was converted under the terms of the Washington Naval Treaty to an
Kaga after her modernization, with her distinctive downward-facing funnel
Kaga as completed, with all three flight decks visible. In fact, the intermediate deck was not a flight deck. It was not comunicating with the upper hangar.
Kaga fitting-out in 1928. This stern view shows the long funnel extending aft below the flight deck, and three 200 mm guns in casemates.
Kaga undergoing post-launch trials off Tateyama, 15 September 1928
Akagi was an aircraft carrier built for the Imperial Japanese Navy. Though she was laid down as an Amagi-class battlecruiser, Akagi was converted to an aircraft carrier while still under construction
Japanese aircraft carrier Kaga
…or battlecruiser hulls into aircraft carriers of up to 33,000 long tons (34,000 t) standard displacement. The incomplete battlecruisers Amagi and Akagi were initially selected, but the Great Kantō earthquake of 1923 damaged Amagi's hull beyond economically feasible repair, and Kaga was selected as her…
Akagi conducting flight operations, April 1942
Akagi on 6 April 1925, prior to her launch at Kure
Akagi on trials off the coast of Iyo, 17 June 1927, with all three flight decks visible. In fact, the intermediate deck was not a flight deck.
Akagi underway in 1929 with aircraft on the upper flight deck and two 20 cm gun turrets on the middle flight deck