8"/45 caliber Mark 6 | |
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Type | |
Place of origin | United States |
Service history | |
In service | 1906 |
Used by | |
Wars | |
Production history | |
Designer | Bureau of Ordnance |
Designed | 1900 |
Manufacturer | U.S. Naval Gun Factory |
No. built | 148 (Nos. 108–255) |
Variants | Mark 6 Mod 1 – Mod 4 |
Specifications | |
Mass |
|
Length | 30 ft 9 in (9.37 m) |
Barrel length | 30 ft 0 in (9.14 m) bore (45 calibers) |
Shell |
|
Caliber | 8 in (203 mm) |
Recoil | 28.5 in (720 mm) max |
Elevation |
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Traverse |
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Rate of fire | 1 to 2 rounds per minute |
Muzzle velocity |
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Effective firing range |
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The 8"/45 caliber Mark 6 gun (spoken "eight-inch-forty-five--caliber") were used for the secondary batteries of the United States Navy's last pre-dreadnought battleships and refitted in older armored cruisers main batteries. [1]
The 8-inch (203 mm)/45 caliber gun was developed after the Spanish–American War to use the new smokeless powder that had recently been adopted by the Navy. This gun was much stronger than its predecessor, the 8-inch/40 caliber gun, [1] which were incapable of handling the new powder. This was shown when the muzzle of one of Colorado 's guns blew off on 22 June 1907, during gunnery practice off Shantung. [2] The Mark 6, gun Nos. 108–255, 148 in total, was constructed of tube, jacket, four hoops a locking ring and the liner with a Welin breech block. These were all constructed of nickel steel. There were a total of eight different Mods, Mark 6 Mod 0 to Mark 6 Mod 7, with different liners, breech mechanisms, chambers, and rifling being used. [1] [3]
The guns mounted in the Virginia-class battleships were in an unusual two-level turret with the 8-inch guns on top of the larger 12-inch (305 mm) guns. This arrangement ultimately proved unsuccessful but helped the Navy in the successful development of superfiring turrets later used in the dreadnought South Carolina. [1] [3]
Due to an older 8-inch/40 caliber Mark 5s muzzle blowing off during gunnery practice in Colorado on 22 June 1907, all Mark 5s were removed from service, rebuilt, and placed in reserve. Because of this, all Pennsylvania-class armored cruisers and the armored cruiser New York, were refit with the newer Mark 6 guns. [2] [3]
With the signing of the Washington Naval Treaty, the pre-dreadnoughts still in service were required to be scrapped. This surplussed up to 48 guns, which the Army used for coastal artillery, using new mountings and new lighter, and more streamlined, projectiles. [1] [3]
Ship | Gun Installed | Gun Mount |
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USS Virginia (BB-13) | Mark 6: 8"/45 caliber |
|
USS Nebraska (BB-14) | Mark 6: 8"/45 caliber |
|
USS Georgia (BB-15) | Mark 6: 8"/45 caliber |
|
USS New Jersey (BB-16) | Mark 6: 8"/45 caliber |
|
USS Rhode Island (BB-17) | Mark 6: 8"/45 caliber |
|
USS Connecticut (BB-18) | Mark 6: 8"/45 caliber | Mark 12: 4 × twin turrets |
USS Louisiana (BB-19) | Mark 6: 8"/45 caliber | Mark 12: 4 × twin turrets |
USS Vermont (BB-20) | Mark 6: 8"/45 caliber | Mark 12: 4 × twin turrets |
USS Kansas (BB-21) | Mark 6: 8"/45 caliber | Mark 12: 4 × twin turrets |
USS Minnesota (BB-22) | Mark 6: 8"/45 caliber | Mark 12: 4 × twin turrets |
USS New Hampshire (BB-25) | Mark 6: 8"/45 caliber | Mark 12: 4 × twin turrets |
USS Mississippi (BB-23) | Mark 6: 8"/45 caliber | Mark 12: 4 × twin turrets |
USS Idaho (BB-24) | Mark 6: 8"/45 caliber | Mark 12: 4 × twin turrets |
USS New York (ACR-2) | Mark 6: 8"/45 caliber | Mark 12: 2 × twin turrets |
USS Pennsylvania (ACR-4) | Mark 6: 8"/45 caliber | Mark 12: 2 × twin turrets |
USS West Virginia (ACR-5) | Mark 6: 8"/45 caliber | Mark 12: 2 × twin turrets |
USS California (ACR-6) | Mark 6: 8"/45 caliber | Mark 12: 2 × twin turrets |
USS Colorado (ACR-7) | Mark 6: 8"/45 caliber | Mark 12: 2 × twin turrets |
USS Maryland (ACR-8) | Mark 6: 8"/45 caliber | Mark 12: 2 × twin turrets |
USS South Dakota (ACR-9) | Mark 6: 8"/45 caliber | Mark 12: 2 × twin turrets |
Up to 48 of these weapons served as coast defense weapons with the United States Army Coast Artillery Corps in World War II. They were designated "8-inch Navy gun Mk.VI M3A2". Twenty-four to thirty-two of these weapons were on the M1 railway mounting, divided into four-gun batteries, stationed in Delaware, Los Angeles, and Puget Sound, among other CONUS locations. Sixteen additional weapons were mounted in two-gun batteries in fixed emplacements on the M1 barbette carriage, with some additional batteries not completed. Most of the fixed weapons were in Alaska, Hawaii, and Puerto Rico. [4]
Four weapons of this type survive, all previously used in coast defense: [5]
The 16 inch gun M1919 (406 mm) was a large coastal artillery piece installed to defend the United States' major seaports between 1920 and 1946. It was operated by the United States Army Coast Artillery Corps. Only a small number were produced and only seven were mounted; in 1922 and 1940 the US Navy surplussed a number of their own 16-inch/50 guns, which were mated to modified M1919 carriages and filled the need for additional weapons.
The QF 4.7-inch Gun Mks I, II, III, and IV were a family of British quick-firing 4.724-inch (120 mm) naval and coast defence guns of the late 1880s and 1890s that served with the navies of various countries. They were also mounted on various wheeled carriages to provide the British Army with a long range gun. They all had a barrel of 40 calibres length.
Seacoast defense was a major concern for the United States from its independence until World War II. Before airplanes, many of America's enemies could only reach it from the sea, making coastal forts an economical alternative to standing armies or a large navy. After the 1940s, it was recognized that fixed fortifications were obsolete and ineffective against aircraft and missiles. However, in prior eras foreign fleets were a realistic threat, and substantial fortifications were built at key locations, especially protecting major harbors.
The QF 6-inch 40 calibre naval gun (Quick-Firing) was used by many United Kingdom-built warships around the end of the 19th century and the start of the 20th century.
The Ordnance QF Hotchkiss 6 pounder gun Mk I and Mk II or QF 6 pounder 8 cwt were a family of long-lived light 57 mm naval guns introduced in 1885 to defend against new, small and fast vessels such as torpedo boats and later submarines. There were many variants produced, often under license which ranged in length from 40 to 58 calibers, but 40 caliber was the most common version.
The 14-inch/45 caliber gun,, whose variations were known initially as the Mark 1, 2, 3, and 5, and, when upgraded in the 1930s, were redesignated as the Mark 8, 9, 10, and 12. They were the first 14-inch (356 mm) guns to be employed by the United States Navy. The 14-inch/45 caliber guns were installed as the primary armament aboard all of the United States Navy's New York-class, Nevada-class, and Pennsylvania-class battleships. The gun also saw service in the British Royal Navy, where it was designated BL 14 inch gun Mk II.
The 16"/50 caliber Mark 2 gun and the near-identical Mark 3 were guns originally designed and built for the United States Navy as the main armament for the South Dakota-class battleships and Lexington-class battlecruisers. The successors to the 16"/45 caliber gun Mark I gun, they were at the time among the heaviest guns built for use as naval artillery.
The 8"/55 caliber gun formed the main battery of United States Navy heavy cruisers and two early aircraft carriers. United States naval gun terminology indicates the gun barrel had an internal diameter of 8 inches (203 mm), and the barrel was 55 calibers long.
The 8-inch Navy gun Mk.VI M3A2 on railway mount M1A1 was a World War II improved replacement for the World War I-era 8-inch M1888 gun and was used by the US Army's Coast Artillery Corps in US harbor defenses. The guns were also mounted in fixed emplacements on the barbette carriage M1A1. These guns were US Navy surplus 8"/45 caliber guns from battleships scrapped under the 1922 Washington Naval Treaty. Mark VI was the Navy designation. The Army designation for this gun was "8-inch Navy gun Mk.VI M3A2".
The 8-inch gun M1888 (203 mm) was a U.S. Army Coast Artillery Corps gun, initially deployed 1898–1908 in about 75 fixed emplacements, usually on a disappearing carriage. During World War I, 37 or 47 of these weapons were removed from fixed emplacements or from storage to create a railway gun version, the 8-inch Gun M1888MIA1 Barbette carriage M1918 on railway car M1918MI, converted from the fixed coast defense mountings and used during World War I and World War II.
The 6-inch gun M1897 (152 mm) and its variants the M1900, M1903, M1905, M1908, and M1 were coastal artillery pieces installed to defend major American seaports between 1897 and 1945. For most of their history they were operated by the United States Army Coast Artillery Corps. They were installed on disappearing carriages or pedestal mountings, and during World War II many were remounted on shielded barbette carriages. Most of the weapons not in the Philippines were scrapped within a few years after World War II.
The 8"/30 caliber gun formed the main batteries of the United States Navy's "New Navy". They were a US naval gun that first entered service in 1886, and were designed for use with the first three protected cruisers, Atlanta, Boston and Chicago.
The 10"/40 caliber gun Mark 3 was used for the main batteries of the United States Navy's last generation of armored cruisers, the Tennessee-class. The Mark 3s were the last, and most powerful, 10-inch (254 mm) guns built for the US Navy.
The 7"/44 caliber gun Mark 1 and 7"/45 caliber gun Mark 2 were used for the secondary batteries of the United States Navy's last generation of pre-dreadnought battleships, the Connecticut-class and Mississippi-class. The 7-inch (178 mm) caliber was considered, at the time, to be the largest caliber weapon suitable as a rapid-fire secondary gun because its shells were the heaviest that one man could handle alone.
The 6"/30 caliber gun Mark 1 were used for the primary battery of the United States Navy's dispatch vessel Dolphin with the Mark 2 being used in the secondary batteries for its "New Navy" protected cruisers Atlanta, Chicago, and Boston and the Mark 3 used for the primary and secondary batteries in the succeeding early protected cruisers in addition to secondary batteries in the "Second Class Battleships" Maine and Texas.
The 4"/40 caliber gun was used for the secondary batteries on the United States Navy's battleship Iowa, Columbia-class protected cruisers, and the armored cruiser New York, and was the primary batteries on the gunboats Nashville, Wilmington, and Helena.
The 5″/40 caliber gun were used in the secondary batteries of the United States Navy's early battleships, armored cruisers, protected cruisers, unprotected cruisers, and auxiliary cruisers.
The 5"/50 caliber gun was the first long barrel 5-inch (127 mm) gun of the United States Navy and was used in the secondary batteries of the early Delaware-class dreadnought battleships, various protected cruisers, and scout cruisers. They were also refitted in the secondary batteries of the armored cruiser New York and the New Orleans-class protected cruisers. They were later used on cargo ships, store ships and unclassified auxiliaries during World War II as well as in emergency coastal defense batteries.
The 6"/50 caliber gun Mark 6 and Mark 8 were used for the secondary batteries of the United States Navy's Maine-class and Virginia-class battleships, as well as the Pennsylvania-class and Tennessee-class armored cruisers. They were also used as the main battery on the St. Louis-class protected cruisers.
The EOC 8 inch 45 caliber were a family of related 8-inch (203 mm) 45 caliber naval guns designed by the Elswick Ordnance Company and manufactured by Armstrong for export customers before World War I. In addition to being produced in the United Kingdom licensed variants were produced in Italy and in Japan. Users of this family of gun included the navies of Argentina, Chile, China, Italy, Japan and Spain. This family of guns saw action in the Spanish–American War, Boxer Rebellion, Russo-Japanese War, Italo-Turkish War, World War I and World War II. In addition to its naval role it was later used as coastal artillery and siege artillery after the ships it served on were decommissioned.