12-inch/45-caliber Mark 5 gun

1906 American naval gun 12-inch/45-caliber Mark 5 Naval Gun 12-45 mk5 Connecticut gun pic.jpg 300 Mark 5 gun being hoisted aboard Connecticut BB-18 6 United States Naval gun Coastal defence YES YES 1906–1930 United States Navy Greek Navy World War I Russian Civil War Greco-Turkish War World War II Bureau of Ordnance 1903 U.S. Naval Gun Factory 53 ST MT on 45 ft 0 in m 2 bore (45 calibers) 870 lb 12 in 0 2–3 rpm 2,700 ft/s 20000 yd 0 at 15° elevation 30000 yd 0 at 47° elevation (as coastal artillery) −5° to +15° The 12-inch/45-caliber Mark 5 gun was an American naval gun that first entered service in 1906. Initially designed for use with the Connecticut battleship 0 of pre-dreadnought battleships, the Mark 5 continued in service aboard the first generation of American dreadnoughts. Design and development The 12 in 0 on out/45-caliber Mark 5 naval gun was designed as an incremental improvement upon the preceding American naval gun, the 12-inch/40-caliber gun Mark 4.DiGiulian Tony USA 12"/45 (30.5cm) Mark 5 and Mark 6 http://www.navweaps.com/Weapons/WNUS_12-45_mk5.php Navweaps.com 11 April 2016 18 October 2016 https://web.archive.org/web/20090219123159/http://navweaps.com/Weapons/WNUS_12-45_mk5.htm 19 February 2009 live As such, it was a very similar weapon, having been lengthened by 5 calibers to allow for improved muzzle velocity, range, and penetrating power. Designed to the specifications of the Bureau of Ordnance, the Mark 5 was constructed at the U.S. Naval Gun Factory in Washington, D.C. Washington Navy Yard: History of the Naval Gun Factory, 1883-1939 https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/w/washington-navy-yard-history-naval-gun-factory.html history.navy.mil 8 November 2015 Measurements and capabilities The Mark 5 weighed 53 ST on and was capable of firing 2 to 3 times a minute. At maximum elevation of 15° it could fire an 870 lb shell approximately 20000 yd. However, this range was largely academic at the time the gun was initially designed, as no rangefinding techniques had yet been developed capable of accurately firing beyond about 10000 yd. With an initial muzzle velocity of 2700 ft/s, the gun had a barrel life of 175 rounds, and was capable of firing either armor-piercing or common projectiles.Friedman (1978), p. 153. As designed, the Mark 5 was capable of penetrating 16.6 in of Harvey plated side armor at 6000 yd, 12.2 in at 9000 yd, and 9.9 in at 12000 yd. By comparison the 12-inch/40-caliber Mark 4 it replaced could only penetrate 14.6 in, 11.6 in, and 9.4 in at those distances, respectively. Naval service right|thumb|After six Mark 5 guns aboard USS Delaware, 1913. The Mark 5 entered service in 1906 and remained the primary battleship gun for all American battleships commissioned before 1912, at which point it was replaced by the 12"/50-caliber Mark 7. All told, the Mark 5 would arm 14 battleships of five different classes, making it the most-used main gun in American battleship history. Despite this distinction, the only Mark 5 guns ever to be fired in anger were actually in Greek, and not American, service. The ex-Mississippi battleship 2s Greek battleship Kilkis 2 and Greek battleship Lemnos 2, sold to the Royal Hellenic Navy in 1914, fought in both the Allied Intervention in the Russian Civil War, and the Greco-Turkish War. Though during World War I the Mark 5 would cross the Atlantic for duty aboard two of the American battleships serving in the 6th Battle Squadron of the Grand Fleet, it was never fired in any engagement, as no battles were fought with the German High Seas Fleet in 1918. The five classes armed with the Mark 5 were: Connecticut-class Mississippi-class South Carolina battleship 0 Delaware battleship 0 Florida battleship 0 In American service, the Mark 5 remained afloat (albeit in dwindling numbers) until 1930, when the last guns were removed from the Floridas in compliance with the terms of the London Naval Treaty.BB-30 Florida Class http://www.globalsecurity.org/military/systems/ship/bb-30.htm globalsecurity.org 27 April 2005 11 February 2009 https://web.archive.org/web/20090216172905/http://www.globalsecurity.org/military/systems/ship/bb-30.htm 16 February 2009 live Survivor A Mark 5 Mod 8 gun is displayed at Fort Hamilton in Brooklyn, New York, representative of the general type of coast artillery guns the fort had. Incident thumb|right|View looking aft along the port side, showing barrel of burst 12-inch gun on deck with the gun's rear portion in Turret # 2. Photographed at the Philadelphia Navy Yard, Pennsylvania, 25 September 1916. Note holes in superstructure and in the "cage" foremast caused by this accident. During the summer of 1916, Michigan BB-27 2 blew out her left hand gun in turret No. 2 during target practice. After an investigation of South Carolina BB-26 2s guns it was discovered that copper deposits from the driving bands on the projectiles had narrowed the bores of the barrel enough that it caused the projectiles to slow down. This problem, known as "copper choke", allowed the pressure in the barrel to increase to dangerous levels. Lapping heads, to remove these deposits, were issued for all guns 12-inch and larger throughout the fleet. The lapping heads were later replaced by wire and pissaba brushes.http://www.navweaps.com/Weapons/Gun_Data_p3.php Definitions and Information about Naval Guns Part 3 - Miscellaneous Definitions Navweaps 7 May 2016 18 October 2016 Coastal artillery Following the signing of the Washington Naval Treaty in 1922, many of the Mark 5 guns in service were removed from sea duty and transferred to the U.S. Army for use as coastal artillery. In this capacity, the maximum range of the Mark 5 increased to 30000 yd, due to the greater elevation that was possible. These guns were not deployed by the US Army, and some were sold to Brazil, where they might still be in use.Coastal Defence Forces (Brazil) http://www.janes.com/articles/Janes-Amphibious-and-Special-Forces/Coastal-Defence-Forces-Brazil.html janes.com 13 August 2008 13 February 2009 https://web.archive.org/web/20090224201731/http://www.janes.com/articles/Janes-Amphibious-and-Special-Forces/Coastal-Defence-Forces-Brazil.html 24 February 2009 live In Greek service, the guns removed from Lemnos were emplaced on the island of Aegina, where they helped to defend the approaches to the port of Athens. Greek Navy Ships – Lemnos http://www.history.navy.mil/photos/sh-fornv/greece/grksh-hl/lemnos.htm https://archive.today/20010802110523/http://www.history.navy.mil/photos/sh-fornv/greece/grksh-hl/lemnos.htm dead 2 August 2001 Naval Historical Center 27 March 2001 17 November 2009 See also Weapons of comparable role, performance and era 305mm/45 Modèle 1906 gun – French equivalent BL 12-inch Mk X naval gun – British equivalent EOC 12-inch 45-calibre naval gun ("41st Year Type") – British-manufactured Japanese equivalent References External links June 2017 Category:Naval guns of the United States Category:305 mm artillery Category:Coastal artillery