sorry if the background text seems a little bit rush and bare bones, I promise once I upload it to my Zipang thread, this class of carrier will be too much more flush up back sorry
Displacement: 45,800 tonnes standard
Dimensions: 920ft x 101ft x 32ft
Machinery: 4-shaft geared turbines, 20 water tube boiler, 120,500 shp
Speed: 26 knts
Endurance: 8,000 nautical miles at 10 knots
Armament: kuuryū as Commissioned: 1926
8x2 12cm Type-25 DP
4x2 3cm Type 26 autocannons
2x1 12.7mm Machine Guns
Armament: kuuryū as of: 1942
8x2 12cm Type-25 DP
10x2 3cm Type 28 mod 2 autocannons
2x1 12.7mm Machine Guns
Aircraft
Upper hangar 648ft long; 71ft wide; 18ft high; capacity for 26 aircraft, plus 4 dismantled aircraft
Lower hangar 683ft long; 77ft wide; 17ft high; capacity for 41 aircraft, plus 6 dismantled aircraft
Dark park: 6 permanent parking positions
Total capacity: 67 aircraft ( 107 including deckpark)
Armour:
Main Belt: 8 inches
Deck: 4 inches over boiler rooms, machinery spaces and magazines
Flight deck: 1 inches
Torpedo protection: double space bulkheads
originally laid down as the absolutely colossal Tajima class superdreadnought, kuuryū and atsuiryū were for quite some time, the largest aircraft carriers in terms of displacement and overall size, although compared two other contemporary carriers of day they're air wing was on the lower end in terms of size at only 67, not including a deckpark.
throughout the late 20s and early 30s, both massive carriers would be responsible for forging, the zipang navys aircraft carrier doctrine, with them being classified as a assault carriers based on their aircraft complement, while the smaller carriers were classified as scout carriers due to their much higher speed and smaller air group, going into 1930 for both carriers would take part in the Zipang- Japanese war, although the Japanese had the advantage when it came to aircraft carrier doctrine, kuuryū and atsuiryū made up for the disadvantages in advanced aircraft tactics with sheer size, but with the wars end on November the 9th 1934, both ships would come under the control of the Imperial Japanese Navy, and would later be incorporated into the IJN first carrier division.
both carriers would lend their aircraft to the attack on Pearl Harbour, on the 5th of December 1941, they would also take part in the Battle of Darwin on the 19th of February 1941 with aircraft from kuuryū being credited with sinking the destroyer USS William B. Preston, and damaging the USAT Meigs, Both carriers will also take part in the capture of the Philippines in Mid 1941.
Going into 1942 both carriers would receive updated aircraft, along with a refit improve they pretty weak anti aircraft capabilities, both carriers would take part during the battle of the Coral Sea, with their aircraft helping to sink the carrier USS Lexington and damaging a US fleet oiler, both carriers would also be present as part of the first carrier division at the Battle of Midway, where they would go on to be attacked by US land base dever and carrier based aircraft, fortunately both carriers would come out of the battle relatively unscathed unlike the other members of the first carrier division and the escorts.
Ships in class: (laid down-launched-commissioned - fate)
Kuuryū (CV-4) 1919-1922-1926 - ?
Atsuiryū (CV-5) 1919-1922-1926 - ?