This pair were really semi-sisters. Soryu was slightly smaller and featured a starboard island. Hiryu on the other hand was larger than Soryu, featured a port side island, and slightly more AA armarment. Commishioned in 1937, these ships were comprable to the American Yorktown class. They were present at all major operations of the early years of WW II. Soryu was also the first carrier to operate the D4y1 "Suisei" dive bomber. These ships formed the 2nd carrier strike force under the command of Admiral Yamaguchi. They were sunk at Midway after American attacks ignited the bombs of re-arming planes in the Hangar Deck.
Displacement: 19,800 tons full load
Dimensions: 728 x 70 x 25 feet/221.9 x 21.3 x 7.6 meters
Extreme Dimensions: 746.5 x 85.5 x 25 feet/227.5 x 26 x 7.6 meters
Propulsion: Steam turbines, 8 boilers, 4 shafts, 152,000 shp, 34.5 knots
Crew: 1100
Armor: 1.8 inch belt, 1-2.2 inch decks
Armament: 6 dual 5/40 DP, 28 25 mm AA
Aircraft: 63 (71 maximum)
Concept/Program: First large purpose-built Japanese aircraft carrier; design was the basis for all later fleet carrier construction. The program originated as an "flight deck cruiser" designed to get around treaty restrictions, but the design became a full fleet carrier when the treaties were abrogated. Hiryu was intended as a sistership but was completed to a modified design.
Design: A completely new design, and relatively lightly built. Dual hangars with full-length flight deck and starboard-side island. Cruiser-type machinery used for high speed.
Operational: Generally operated with semi-sister Hiryu as part of IJN's second carrier division.
Departure from Service/Disposal: Sunk at Midway.
Hiryu:
Displacement: 21,900 tons full load Dimensions: 731.5 x 73 x 25.5 feet/223 x 22.25 x 7.8 meters Extreme Dimensions: 746 x 88.5 x 25.5 feet/227.4 x 27 x 7.8 meters Propulsion: Steam turbines, 8 boilers, 4 shafts, 153,000 shp, 34.3 knots Crew: 1101 Armor: 3.5-5.9 inch belt, 1-2.2 inch deck Armament: 6 dual 5/40 DP, 31 25 mm AA Aircraft: 64 (73 maximum) Concept/Program: An improved version of Soryu, often considered to be her sistership. Design: Soryu design with strengthened hull, raised forecastle, improved armor, a port-side island, and other minor changes. Operational: Generally operated with semi-sister Soryu as part of IJN's second carrier division. Departure from Service/Disposal: Sunk at Midway.