Post by Diarist on Apr 28, 2017 5:29:03 GMT 1
The Kongō-class battlecruiser (金剛型巡洋戦艦 Kongō-gata jun'yōsenkan?) was a class of four battlecruisers built for the Imperial Japanese Navy (IJN) immediately before The Great War. Designed by British naval architect George Thurston, the lead ship of the class was the last Japanese capital ship constructed outside Japan, by Vickers.
During the late 1920s, all but Hiei were reconstructed and reclassified as battleships. After the signing of the London Naval Treaty in 1930, Hiei was reconfigured as a training ship to avoid being scrapped. Following Japan's withdrawal from the London Naval Treaty, all four underwent a massive second reconstruction in the late 1930s. Following the completion of these modifications, which increased top speeds to over 30 knots (56 km/h; 35 mph), all four were reclassified as fast battleships.
Design
The design of the Kongō-class battlecruisers came about as a result of the IJN's modernization programs, as well as the perceived need to compete with the British Royal Navy.
In March 1908, the Royal Navy launched HMS Invincible at Newcastle upon Tyne. Armed with eight 12-inch (30 cm) main guns, Invincible rendered all current—and designed—Japanese capital ships obsolete by comparison. In 1911, the Japanese Diet passed the Emergency Naval Expansion Bill, authorizing the construction of one battleship (Fusō) and four armoured cruisers, to be designed by British naval architect George Thurston. In his design of the class, Thurston relied on many techniques that would eventually be used by the British on the Tiger class.
Under the terms of the contract signed with Vickers in November 1910, one member of the Kongō class - the lead ship Kongō - was to be built in Britain and Vickers were to maximize technology transfer to Japan. The design of the ships was from Vickers Design 472C (corresponding to the Japanese design designation B-46). The original design featured eight or ten 12-inch (304.8 mm) 50-caliber guns, sixteen 6-inch (152 mm) guns, and eight 21-inch (533 mm) torpedo tubes. Cdr Katô Hirohasu pushed for the adoption of a new 14-inch (360 mm)/45 calibre gun that was currently under development. After trials of the new gun, which were witnessed by both the Japanese Navy and Royal Navy, the Japanese made the decision on 29 Nov 1911 to use the new gun despite the keel having already been laid down on 17 January 1911, and the resulting need to quickly make a large number of alternations to the design, so as to not prolong the construction.
The final design of the battlecruisers resulted in an improved version of the Lion class, displacing an estimated 27,940 tonnes (27,500 long tons). It also called for eight 14-inch guns mounted in four twin gun turrets (two forward and two aft) with a top speed of 27.5 knots (50.9 km/h; 31.6 mph).
To ensure transfer of the latest design knowledge to Japan more than 100 technical specialists were sent on 18 months secondments from Japan to Vickers during the construction phase of Kongō. If superintendents, supervisors and trial witnesses are also included then approximately 200 Japanese spent time in Britain.
Ships
Kongō Vickers, Barrow-in-Furness, completed 16 August 1913
Hiei Yokosuka Naval Arsenal, Yokosuka, completed 4 August 1914
Kirishima Mitsubishi Shipyard Co., Nagasaki, completed 19 April 1915
Haruna Kawasaki Dockyard Co., Kobe, completed 19 April 1915
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