History

Kaga (加賀) was an aircraft carrier built for the Imperial Japanese Navy (IJN) and was named after the former Kaga Province in present-day Ishikawa Prefecture. Originally intended to be one of two Tosa-class battleships, Kaga was converted under the terms of the Washington Naval Treaty to an aircraft carrier as the replacement for the battlecruiser Amagi, which had been irreparably damaged during the 1923 Great Kantō earthquake. Kaga was rebuilt in 1933–1935, increasing her top speed, improving her exhaust systems, and adapting her flight decks to more modern, heavier aircraft.


Design

The Treaty authorized conversion of two battleship 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 replacement. 

The formal decision to convert Kaga to an aircraft carrier was issued 13 December 1923, but no work took place until 1925 as new plans were drafted and earthquake damage to the Yokosuka Naval Arsenal was repaired. She was officially commissioned on 31 March 1928, but this signified only the beginning of sea trials. She joined the Combined Fleet (Rengō Kantai) on 30 November 1929 as the IJN's third carrier to enter service, after Hōshō (1922) and Akagi (1927).[4]

Kaga was completed with a length of 238.5 meters (782 ft 6 in) overall. She had a beam of 31.67 meters (103 ft 11 in) and a draft at full load of 7.92 meters (26 ft). She displaced 26,900 long tons (27,300 t) at standard load, and 33,693 long tons (34,234 t) at full load, nearly 6,000 long tons (6,100 t) less than her designed displacement as a battleship.[5] Her complement totaled 1,340 crewmembers.[6]