Inter-World War Japanese Battleships

The London Naval Agreement of 1936 was drawn up in the absence of Japan and Italy, the former because its demands for parity with the other two major naval powers was rebuffed, the latter feeling insulted by sanctions imposed by the League of Nations in the wake of the Italian invasion of Ethiopia. This treaty, between the isolationist-minded United States, Britain, France, and the Soviet Union (whose few old battleships were in a dismal state), kept the Washington Treaty’s 35,000-ton limit; eliminated the restriction on the number of battleships per nation; stipulated that the naval powers would keep each other informed of battleship construction particulars; and provided for the reduction of maximum gun caliber to 14 inches from 16 inches—subject to Japan’s agreement. Japan, which had pioneered the 16-inch gun, refused. (Actually, the Japanese 16-inch gun on the Nagatos preceded the similarly armed U.S. Colorados by only four months.) A supplementary agreement raised the maximum permitted displacement to 45,000 tons.

Japan modernized all of its World War I-era dreadnoughts, installing new engines and boilers, reinforcing horizontal armor, and fitting anti-torpedo bulges (often filled with steel tubes) on the hulls.

The battleship modernization programs were getting under way just as the air forces of the major powers finally developed the weapon that could sink a battleship: the aerial torpedo, which had actually been in the armories of the naval powers since late in World War I. However, an efficient delivery vehicle for the aerial torpedo had to await the aviation revolution of the mid-1930s, which introduced monocoque all-metal construction, retractable landing gear, variable-pitch propellers, advanced control flaps, and enclosed cockpits. Even so, despite such technological advances, only the IJN had an effective torpedo-bomber at the beginning of World War II; the Royal Navy Blackburn Skua and the U.S. Navy Douglas Devastator never sank any major surface warship, and the latter was far more likely to be shot down by its target. In an indication of the artificiality of the naval exercises of the times, in the mid-1920s Royal Navy torpedo-bombers were scoring 30–60 percent hits, an extraordinarily accurate—and misleading—rate.

So it was that even airpower enthusiasts derided the new carrier as nothing more than a sinkable airfield, housing underpowered and weak warplanes. In only one case, the Prince of Wales, was a heavy surface warship ever sunk by land-based level bombers. (Even then, the battleship had already been severely wounded by aerial torpedoes, and the level bombers were Imperial Japanese Navy warplanes.)

The superb Imperial Japanese Navy was the most battleship-oriented service of World War II. Nonetheless, it possessed the superior air arm; and it was that force—perhaps paradoxically—that spelled the end of the battleship. Just months before the opening of the Pacific War, the IJN had grouped its carriers into a task force, and it was this task force that rampaged through the Pacific in 1941–1942, sinking every major enemy warship in its path.

The oldest battleships deployed by Japan during World War II were Nippon’s first dreadnought class, the four impressive Kongos (Kongo, Hiei, Haruna, and Kirishima). These were the only warships ever to have begun their service lives as battle cruisers and to be later rebuilt into battleships. They were slightly faster than contemporary RN battle cruisers, yet their protection was almost on a battleship level. Although the designs were British, Kongo was the last Japanese battleship to be actually built abroad (design and construction by Vickers of Great Britain). In a foresighted move, similar to that of the U.S. Navy with the Iowas, all four units were modernized, beginning in the mid-1930s, to increase speed specifically to serve as escorts for Japan’s projected aircraft carrier task force in the event of war. They emerged from this modernization as true battleships. (Hiei, declared in violation under the terms of the Washington Treaty, was partially disarmed, stripped of heavy side armor, and lost 25 of its 36 boilers to reduce speed; it was rearmed, rearmored, and reboilered in the 1930s.) This was a time when the IJN and the U.S. Navy considered carriers to be primarily the eyes of the fleet. The Kongos enjoyed so high a reputation that the British, during World War I, had requested them on loan!

As with the Kongos, the next Japanese battleship class, the Fusos, Japan’s first super-dreadnoughts, were completely modernized in the mid-1930s and given bizarre pagoda foremasts, in which platforms, bridges, masts, and the like seemed piled one on top of the other to no discernable pattern. Both were sunk at the Battle of Surigao Strait on 25 October 1944. The Ise class (Ise and Hyuga), follow-ons to the Fuso class, were also modernized during the 1930s.

The Nagatos were the first exclusively Japanese-designed battleships; previous battleships after Kongo had been built in Japan to foreign plans. They were also the last of the World War I-era Japanese capital ships. Although roughly contemporaneous to the U.S. Colorados, their big-gun calibers were slightly larger and their speed 5.5 knots faster. They, too, were rebuilt in the 1930s, although their engines were not replaced, as with previous classes of Japanese battleships.

The Japanese clearly got their money’s worth from modernized Nagato. That battleship sank three U.S. destroyers and the small U.S. carrier Gambier Bay in one of only two cases of a battleship sinking an aircraft carrier; it even survived the war, the only Japanese battleship with that distinction. Her sister ship, Mutsu, was destroyed by yet another of those mysterious battleship explosions, in June 1943, leaving 1,222 dead. (The explosion was so great that postwar U.S. Navy divers could not even locate this battleship’s aft portion. Some have speculated that liquor illicitly brewed from Japanese torpedo fuel caused Mutsu’s demise (Spector, p. 158).

Japan’s final battleship class, the four Yamatos, saw only Yamato and Musashi completed as battleships in 1941 and 1942, respectively. Shinano was converted to an aircraft carrier while on the stocks in 1944; No. 111 was broken up uncompleted in 1942, and No. 797 was never even laid down. These battleships have certainly earned their place in history and myth as by far the largest and most powerful capital ships ever built. They were not mere exercises in gigantism; rather they were the result of Japan’s realization that it could never match the United States battleship-for-battleship—but it could build individual units that were bigger and more powerful. The class was intentionally constructed so large that any U.S. ship built to match would not be able to transit the Panama Canal (and thus was not likely to be built in the first place).

The Yamatos displaced 63,000 tons, their armor protection exceeded that of all other battleships, and they were armed, uniquely, with nine 18-inch main battery guns. The units were constructed in the utmost secrecy, surrounded by so many concealing sisal mats that a shortage of the fiber led to complaints from Japan’s vital fishing industry, which needed the fiber for lines. (Even the special gun-carrying freighter was shrouded in sisal.) The sisal must have done its job well enough: Only two known photographs exist of these monster warships. Their guns were so heavy that a special freighter had to be constructed to transport them from their maker to the shipyards. Yet they never fired their guns in anger. Yamato and Musashi were dispatched by U.S. naval warplanes (in 1945 and 1944, respectively). Carrier Shinano was sunk by a U.S. submarine in 1944. And Japan actually proposed two super Yamatos of 70,000 tons and even larger guns. Although the Japanese built mockups of the magazines and handling rooms, reality prevailed, and the project was dropped in 1942.

Considering the construction and extensive modernization of battleships during the 1930s, the world’s major naval powers on the eve of World War II obviously looked upon the battleship as the backbone of the fleet. That would change in the crucible of battle.