12-inch/45-caliber Mark 5 gun
The 12″/45 caliber Mark 5 gun was an American naval gun that first entered service in 1906. Initially designed for use with the Connecticut-class of pre-dreadnought battleships, the Mark 5 continued in service aboard the first generation of American dreadnoughts.
Mark 5 gun being hoisted aboard USS Connecticut
After six Mark 5 guns aboard USS Delaware, c. 1913.
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.
Connecticut-class battleship
The Connecticut class of pre-dreadnought battleships were the penultimate class of the type built for the United States Navy. The class comprised six ships: Connecticut, Louisiana, Vermont, Kansas, Minnesota, and New Hampshire, which were built between 1903 and 1908. The ships were armed with a mixed offensive battery of 12-inch (305 mm), 8-inch (203 mm), and 7-inch (178 mm) guns. This arrangement was rendered obsolete by the advent of all-big-gun battleships like the British HMS Dreadnought, which was completed before most of the Connecticuts entered service.
USS Connecticut (BB-18)
Kansas on speed trials
One of Connecticut's forward 12-inch guns being installed
Vermont in heavy seas, probably during the cruise of the Great White Fleet