The class met the central requirements for aircraft, speed, protection, and defensive firepower, but it was not the largest carrier Japan could imagine. Admirals Isoroku Yamamoto and Mitsumasa Yonai influenced the specifications while planners worked toward a 1941 readiness deadline. Shokaku and Zuikaku were laid down in 1937 and 1938, launched in 1939, and completed only months before Pearl Harbor. Their schedule shows how doctrinal ambition was narrowed by the need to place two worked-up fleet carriers in service before Japan's strategic window closed.
Chapter · 35:46-44:13
Design compromise under the 1941 deadline
Aircraft capacity, protection, and speed met the central requirements, but schedule and yard capacity kept the class below Japan's largest possible carrier design.