The Imperial Japanese Navy “Eight-Eight” Fleet Program

The concept of the ‘Eight-Eight Fleet’ originated in the aftermath of the Russo-Japanese War with the 1907 Imperial Defense Policy. The policy called for the construction of a battle fleet of eight modern battleships of 20,000 tons each and eight modern armored cruisers of 18,000 tons each. These were to be complemented by the construction of several lesser warship types, including cruisers and destroyers. Furthermore, a motivation to achieve the Eight-Eight Fleet ideal later resulted from an additional expansion of the U.S. Navy under President Woodrow Wilson’s 1919 plan to build another set of 16 capital ships.

Development and Legislative Authorization

The first serious attempt to build an ‘Eight-Eight Fleet’ came in 1910, when the Naval General Staff proposed a building program of eight battleships and eight battlecruisers. However, the Navy Ministry cut back this request for political reasons, to seven battleships and three armored cruisers. The Cabinet eventually recommended just one battleship and four battlecruisers, and the Diet authorized these ships in 1911. The battlecruisers became the Kongō class and the battleship was Fusō: all were technologically advanced ships.

The 1913 program saw a further three battleships authorized, making a total of ‘four-four’. These ships, Yamashiro, Ise and Hyūga, were sister ships or cousins of Fusō. In 1915, the Navy proposed another four battleships, to reach an ‘Eight-Four Fleet’, but this was rejected by the Diet. In 1917, in response to the U.S. Navy’s plan to build an additional ten battleships and six battlecruisers, the Diet authorized a further three battleships; and in 1918 the Cabinet authorized another two battlecruisers. In total, the authorization existed for an ‘Eight-Eight Fleet’.

Modernization and Technological Advancements

The new ships started were the two Nagato-class battleships, the two Tosa-class battleships, and a total of four Amagi-class battlecruisers: all modern, capable ships carrying 16-inch guns. So great, though, was the difference in capability between this new generation of ships and those of just five years previously that the ‘Eight-Eight Fleet’ plan was restarted. On this revised basis, Nagato was now regarded as Ship No. 1 in the new project, and planners now began to write off the older battleships and battlecruisers.

In 1920, a reluctant Diet was persuaded to accept a plan to bring the ‘Four-Four’ set of modern ships up to ‘Eight-Eight’ strength by 1927. This would have involved an additional four ‘fast’ battleships, marginally slower than the Nagato-class and but more powerful, and a further four battleships built with 18-inch guns. Only the two Nagato-class ships were eventually completed in their intended role. One Tosa- and one Amagi-class were completed as aircraft carriers, and the Akagi was originally laid down as a Amagi-class battlecruiser. Additionally, the I-51 was the prototype design for Japan’s first large, long-range submarine.

The Nagato-class Battleship Mutsu

The Nagato-class battleship Mutsu, c. 1925, was nearing completion in 1922 when, under the terms of the 1922 Washington Naval Treaty with Great Britain and the United States, it was to have been broken up or converted into an aircraft carrier but was rescued from its fate. Mutsu was assigned to the Main Body of the 1st Fleet during the Battle of Midway, its most prominent role during the Pacific War. Tragically, the ship sunk in June 1943 after a magazine explosion broke the ship in two, and 1,121 sailors died, while moored at fleet anchorage at Hashirajima. No official acknowledgement of the sinking was made until after the end of the war.

Summary of the Fleet Construction Program

• Fusō-class (1911): Initial battleship authorized in the naval budget; technologically advanced for its time.
• Kongō-class (1911): Four battlecruisers authorized by the Diet.
• Ise-class (1913): Includes Ise and Hyūga, authorized as sister ships or cousins of Fusō.
• Nagato-class (1916-1918): Modern ships carrying 16-inch guns; Nagato regarded as Ship No. 1.
• Amagi-class: Four battlecruisers planned; Akagi was completed as an aircraft carrier.
• Tosa-class: Two battleships started; one was completed as an aircraft carrier.
• I-51 Submarine: Prototype design for Japan’s first large, long-range submarine (20,000+ nmi range).