8"/45 caliber gun
8"/45 caliber Mark 6 | |
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Admiral Montgomery M. Taylor, Commander-in-Chief of the U.S Navy Asiatic Fleet, and his fleet staff aboard the USS Rochester (CA-2) at Shanghai, China, in 1932. Front row (left to right): Captain Montgomery E. Higgins, M.C.; Captain Ivan E. Bass; Captain Frank J. Fletcher; Admiral Montgomery M. Taylor; Commander Donald B. Beary; Captain Jeffrey F. Kutz, S.C.; and Colonel Jeffrey F. Dyer, U.S. Marine Crops. Back row (not in order): Lieutenant Henri H. Smith-Hutton; Lieutenant Commander Charles A. MacGowan; Lieutenant Commander Philip W. Warren; Lieutenant Commander Francis T. Spellman; and Lieutenant Junior Grade Royal Lovell. Other officers are unidentified. United States Navy Historical Photo #: NH 83799
USS Rochester (CA-2), ex-USS New York (ACR-2), forward 8"/45 Mark 12 turret in 1932.
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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 |
Number built | 148 |
Variants | Mark 6 Mod 1 – Mod 4 |
Specifications | |
Weight |
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Length | 369 in (9.4 m) |
Barrel length | 360 in (9.1 m) bore (45 calibers) |
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Shell |
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Caliber | Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). |
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 primary batteries.[1]
Design
The 8-inch/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"/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 tolal 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]
Service history
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 guns. This arrangement ultimately proved unsuccessful but helped the Navy in in the successful development of superfiring turrets later used in the dreadnought South Carolina.[1][3]
Due to an older 8"/40 caliber Mark 5's muzzle blowing off during gunnery practice in Colorado on 22 June 1907, all Mark 5's 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 about two dozen 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 |
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USS Nebraska (BB-14) | Mark 6: 8"/45 caliber |
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USS Georgia (BB-15) | Mark 6: 8"/45 caliber |
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USS New Jersey (BB-16) | Mark 6: 8"/45 caliber |
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USS Rhode Island (BB-17) | Mark 6: 8"/45 caliber |
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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 |
References
External links
Bluejackets Manual, 1917, 4th revision: US Navy 14-inch Mark 1 gun
Wikimedia Commons has media related to 8"/45 caliber gun. |