A pagoda mast was a type of superstructure erected on a tripod mast that was common on Japanese capital ships that were reconstructed during the 1930s in a bid to improve their fighting performance. These modifications were deemed to be necessary by the Imperial Japanese Navy as a result of the "Battleships Holiday" that was imposed by the Washington Naval Treaty, which strictly limited the construction of new battleships. [1]
Pagoda masts were built on existing tripod masts by adding searchlight and other platforms, lookouts and shelters upon each other, the result resembling a pagoda temple. The superstructures were constructed on the majority of the ships that were rebuilt by the Japanese during the 1930s, including the Kongō-class battlecruisers and the Fusō, Ise, and Nagato-class battleships.
The additional platforms were supported on the ships' original tripod foremasts (a design also extensively used by the Royal Navy), which were suitably strengthened to bear the extra weight. As completed, the masts could reach 40 m (130 ft) or more above the waterline.
Like the British Royal Navy, which was considered to be a likely enemy of Japan in the event of an armed conflict, the Imperial Japanese Navy wanted to prepare their warships for engaging in combat at night. Prior to the outbreak of World War II, powerful searchlights were placed on the pagoda masts for the purpose of illuminating enemy ships at night. However, during the early 1940s, the searchlights mounted on the pagoda became less important as new radar technology was developed that allowed a ship to aim and shoot at targets at night. [2] [3]
In the navies of Europe and the Americas, tall pagoda-style masts were generally frowned upon. Naval architects and sailors from the Western hemisphere claimed that the Japanese battleships were too "top-heavy" and critics often mocked these vessels by nicknaming them "Christmas Trees". Uniquely, the battleship Hiei received a prototype of the pagoda-style tower-mast that would eventually be used on the upcoming Yamato-class battleships, then still in the design phase, rather than the pagoda masts used on her sister ships and other modernized World War I-era capital ships. [4]
During the same interwar period, the Royal Navy implemented the "Queen Anne's Mansions" style conning tower and bridge, either retrofitted World War I-era battleships (three of the Queen Elizabeth class, HMS Renown) or for new battleships (the Nelson and King George V classes). Between World War I and World War II, the US Navy gradually phased out the lattice masts on its Standard-type battleships in favor of tripod masts, and after Pearl Harbor some of the salvaged battleships were reconstructed with masts similar to those on its post-treaty battleships.
Chronological images of the Japanese battleship Ise, showing the development of her pagoda mast over time.
The heavy cruiser was a type of cruiser, a naval warship designed for long range and high speed, armed generally with naval guns of roughly 203 mm (8 inches) in calibre, whose design parameters were dictated by the Washington Naval Treaty of 1922 and the London Naval Treaty of 1930. The heavy cruiser is part of a lineage of ship design from 1915 through the early 1950s, although the term "heavy cruiser" only came into formal use in 1930. The heavy cruiser's immediate precursors were the light cruiser designs of the 1900s and 1910s, rather than the armoured cruisers of the years before 1905. When the armoured cruiser was supplanted by the battlecruiser, an intermediate ship type between this and the light cruiser was found to be needed—one larger and more powerful than the light cruisers of a potential enemy but not as large and expensive as the battlecruiser so as to be built in sufficient numbers to protect merchant ships and serve in a number of combat theatres.
The Pensacola class was a class of United States Navy heavy cruiser, the first "treaty cruisers" designed under the limitations set by the Washington Naval Treaty, which limited cruisers to a maximum of 10,000 long tons (10,160 t) displacement and a maximum main battery caliber of 8-inch (203 mm).
Fusō was the lead ship of the two Fusō-class dreadnought battleships built for the Imperial Japanese Navy. Launched in 1914 and commissioned in 1915, she initially patrolled off the coast of China, playing no part in World War I. In 1923, she assisted survivors of the Great Kantō earthquake.
Hiei (比叡) was a warship of the Imperial Japanese Navy during World War I and World War II. Designed by British naval architect George Thurston, she was the second launched of four Kongō-class battlecruisers, among the most heavily armed ships in any navy when built. Laid down in 1911 at the Yokosuka Naval Arsenal, Hiei was formally commissioned in 1914. She patrolled off the Chinese coast on several occasions during World War I, and helped with rescue efforts following the 1923 Great Kantō earthquake.
Hyūga was the second and last Ise-class battleship built for the Imperial Japanese Navy (IJN) during the 1910s. Although completed in 1918, she played no role in World War I. Hyūga supported Japanese forces in the early 1920s during the Siberian intervention in the Russian Civil War. In 1923, she assisted survivors of the Great Kantō earthquake. The ship was partially modernised in two stages in 1927–1928 and 1931–1932, during which her forward superstructure was rebuilt in the pagoda mast style. Hyūga was reconstructed in 1934–1936, improvements being made to her armour and propulsion machinery. Afterwards, she played a minor role in the Second Sino-Japanese War.
The County class was a class of heavy cruisers built for the Royal Navy in the years between the First and Second World Wars. They were the first post-war cruisers constructed for the Royal Navy and were designed within the limits of the Washington Naval Treaty of 1922. Such ships, with a limit of 10,000 tons standard displacement and 8-inch calibre main guns may be referred to as "treaty cruisers".
Ise was the lead ship of her class of two dreadnought battleships built for the Imperial Japanese Navy (IJN) during the 1910s. Although completed in 1917, she played no role in World War I. Ise supported Japanese forces in the early 1920s during the Siberian Intervention in the Russian Civil War. In 1923, she assisted survivors of the Great Kantō earthquake. The ship was partially modernised in two stages in 1928–1929 and 1931–1932, during which her forward superstructure was rebuilt in the pagoda mast style. Ise was reconstructed in 1934–1937, with improvements to her armour and her propulsion machinery. Afterwards she played a minor role in the Second Sino-Japanese War.
Yamashiro was the second of two Fusō-class dreadnought battleships built for the Imperial Japanese Navy. Launched in 1915 and commissioned in 1917, she initially patrolled off the coast of China, playing no part in World War I. In 1923, she assisted survivors of the Great Kantō earthquake.
Kongō was a warship of the Imperial Japanese Navy during World War I and World War II. She was the first battlecruiser of the Kongō class, among the most heavily armed ships in any navy when built. Her designer was the British naval engineer George Thurston, and she was laid down in 1911 at Barrow-in-Furness in Britain by Vickers Shipbuilding Company. Kongō was the last Japanese capital ship constructed outside Japan. She was formally commissioned in 1913, and patrolled off the Chinese coast during World War I.
Kirishima (霧島) was a warship of the Imperial Japanese Navy which saw service during World War I and World War II. Designed by British naval engineer George Thurston, she was the third launched of the four Kongō-class battlecruisers. Laid down in 1912 at the Mitsubishi Shipyards in Nagasaki, Kirishima was formally commissioned in 1915 on the same day as her sister ship, Haruna. Kirishima patrolled on occasion off the Chinese coast during World War I, and helped with rescue efforts following the 1923 Great Kantō earthquake.
Nagato (長門), named for Nagato Province, was a super-dreadnought battleship built for the Imperial Japanese Navy (IJN). Completed in 1920 as the lead ship of her class, she carried supplies for the survivors of the Great Kantō earthquake in 1923. The ship was modernized in 1934–1936 with improvements to her armor and machinery and a rebuilt superstructure in the pagoda mast style. Nagato briefly participated in the Second Sino-Japanese War in 1937 and was the flagship of Admiral Isoroku Yamamoto during the attack on Pearl Harbor. She covered the withdrawal of the attacking ships and did not participate in the attack itself.
The Ise-class battleships were a pair of dreadnought battleships built for the Imperial Japanese Navy (IJN) during World War I. Both ships carried supplies for the survivors of the Great Kantō earthquake in 1923. They were modernized in 1934–1937 with improvements to their armour and machinery and a rebuilt superstructure in the pagoda mast style. Afterwards they played a minor role in the Second Sino-Japanese War.
The Kongō-class battlecruiser was a class of four battlecruisers built for the Imperial Japanese Navy (IJN) immediately before World War I. Designed by British naval architect George Thurston, the lead ship of the class, Kongō, was the last Japanese capital ship constructed outside Japan, by Vickers at Barrow-in-Furness. Her sister ships, Haruna, Kirishima and Hiei, were all completed in Japan.
The Kuma-class light cruisers were a class of five light cruisers built for and operated by the Imperial Japanese Navy (IJN). The Kuma-class cruisers proved useful in combat operations ranging from the Aleutian Islands to the Indian Ocean throughout World War II.
All or nothing is a method of naval warship armor, best known for its employment on dreadnought battleships. The concept involves heavily armoring the areas most important to a ship while the rest of the ship receives no armor. The "all or nothing" concept avoided light or moderate thicknesses of armor: armor was used in the greatest practicable thickness or not at all, thereby providing "either total or negligible protection". Compared to previous armoring systems, "all or nothing" ships had thicker armor covering a smaller proportion of the hull.
The Eight-Eight Fleet Program was a Japanese naval strategy formulated for the development of the Imperial Japanese Navy in the first quarter of the 20th century, which stipulated that the navy should include eight first-class battleships and eight armoured cruisers or battlecruisers.
Lattice masts, or cage masts, or basket masts, are a type of observation mast common on United States Navy major warships in the early 20th century. They are a type of hyperboloid structure, whose weight-saving design was invented by the Russian engineer Vladimir Shukhov. They were used most prominently on American dreadnought battleships and armored cruisers of the World War I era.
The Fusō-class battleships were a pair of dreadnought battleships built for the Imperial Japanese Navy (IJN) before World War I and completed during it. Both patrolled briefly off the coast of China before being placed in reserve at the war's end. In 1922 Yamashiro became the first battleship in the IJN to successfully launch aircraft.