3rd Naval Armaments Supplement Programme

The 3rd Naval Armaments Supplement Programme (Maru 3 Keikaku) was the third of four expansion plans implemented by the Imperial Japanese Navy between 1930 and the start of World War II. The programme was primarily driven by Japan's response to the London Naval Treaty, which restricted its naval capabilities relative to those of the United States and Britain in terms of tonnage and capital warship numbers. To address these limitations, the Imperial Japanese Navy initiated several construction programmes, including Maru 1 and Maru 2, which focused on building new warships and expanding naval aviation. In 1934, following issues revealed by incidents such as the Tomozuru Incident and the IJN 4th Fleet Incident, where flaws in warship design and construction were identified, the Naval Ministry submitted the second expansion plan, Maru 2, to the Cabinet. This plan aimed to address funding shortfalls and improve naval capabilities by building 48 new warships and creating eight additional Naval Air Groups. By 1937, with the expiration of the London Naval Treaty and Japan's refusal to participate in further disarmament negotiations, a third expansion plan was approved by the Diet. The Maru 3 programme called for the construction of 66 new combat vessels, including two Yamato-class battleships and two Shōkaku-class aircraft carriers, as well as the expansion of the Imperial Japanese Navy Air Service by 14 more Naval Air Groups. The total budget allocated for warship construction was 806,549,000 Yen, with an additional 75,267,000 Yen allocated for naval aviation. The final three vessels of the ...