14-inch/45-caliber gun

The 14-inch/45-caliber gun, (spoken "fourteen-inch-forty-five-caliber"), 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 in 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 battleship, Nevada-class battleship, and Pennsylvania-class battleships. The gun also saw service in the British Royal Navy, where it was designated BL 14-inch gun Mk II.

History
The design of the 14-inch/45-caliber dates to about 1910. They entered service in 1914 aboard USS Texas (BB-35) and her sister ship USS New York (BB-34) shortly after. At the time of their introduction they were intended to fire 1400 lb armor-piercing (AP) projectiles containing a bursting charge of explosive D. Propellant charge was four silk bags of smokeless powder, each of which weighed 105 lb. At a 15-degree angle, the guns could fire a shell out to 23000 yd. Each individual gun weighed 142492 lb with the breech and measured 53 ft in length.

Each of the original Mark 1 built-up guns consisted of a tube without liner, jacket, eight hoops and a screw box liner. To compensate for the problem of gun drooping, four hoop-locking rings were added to the guns. The Mark 3 added three hoop locking rings and contained a longer slide, while the Mark 5 had five hoops total. Owing to the interchangeability of the guns, the battleships fitted with the 14-inch/45-caliber guns often had guns of various Marks installed on each turret.

In the 1930s, the Mark 1, 2, 3, and 5 were upgraded to allow for increased charges and muzzle velocities, resulting in the Mark 8, 9, 10, and 12, respectively. All guns employed a Welin breech block and used a Smith-Asbury mechanism, and, in the case of the Mark 12, chromium plating was introduced to prolong barrel life. These improvements enabled the guns to fire heavier 1500 lb shells, and increasing the gun mount elevation to 30 degrees extended the range of the guns to 36000 yd. The New York-class did not have their turrets modernized because their shell hoists could not accommodate the longer AP and HC shells; instead, a shorter version of shells with windshields were produced for them.

United States Navy
The guns on the two battleships of the New York-class, USS New York (BB-34) and USS Texas (BB-35), the first ship of the Nevada-class, USS Nevada (BB-36) and the first ship of the Pennsylvania-class, USS Pennsylvania (BB-38), saw service in World War II in the role of shore bombardment. New York and Texas bombarded North Africa during landings in 1942, Pennsylvania took part in the Aleutian Islands Campaign and Texas and Nevada shelled Normandy during Operation Overlord in 1944. Throughout 1944 and 1945, Pennsylvania hit many different Pacific islands during their invasions, while New York, Texas and Nevada all took part in the invasion of Iwo Jima and the invasion of Okinawa in 1945.

As they were sunk in the Japanese attack on Pearl Harbor, both USS Oklahoma (BB-37) and USS Arizona (BB-39) never fired their main batteries in combat. Three guns removed from Arizona that in the relining process at the time of Pearl Harbor were installed aboard Nevada in fall 1944 and were used in several shore bombardments in the Pacific. The aft turrets from Arizona (numbers 3 and 4) were salvaged from the wreck and used for United States Army Coast Artillery Corps Battery Arizona on the west coast of Oahu and Battery Pennsylvania on Mokapu Point.

Royal Navy
Eight US Navy standard 14-inch/45-caliber guns, complete with mountings, were built by Bethlehem Steel for the Greek battleship Salamis under construction in Germany. When World War I started, Bethlemen Steel cancelled the sale and offered the guns for purchase by the United Kingdom. The UK agreed to buy them and drew up a design for four monitors. These ships were to have been named after American military leaders but, as the United States was neutral, entered service as the Abercrombie-class monitor with the British service designation "BL 14-inch gun Mk II". Under the British bore-measuring scheme, they were recorded as 44.5 calibers long.

Woolwich Arsenal built two more guns after the same pattern but using wire-wound techniques. Two ex-USN guns were supplied as spares and designated BL 14-inch gun Mk IV due to the different tube makeup, and two US guns with Asbury roller cams were designated Mark V.

In British service it was noted that it took a few shots before the guns warmed up and barrels straightened as the tubes locked together.

The ships were built quickly enough that they could sail to the Eastern Mediterranean in 1915 and participate in the Gallipoli campaign bombarding Ottoman positions.

Surviving examples

 * On USS Texas (BB-35), as of 2024 in drydock in Galveston, Texas. Texas has 9 out of 10 of her original 14-inch gun barrels that served on her from 1914 to 1923. These nine guns served with USS Pennsylvania (BB-38) from 1925 to 1940. They were refurbished, relined, and reinstalled on Texas in late 1944. The serial numbers for these 10 guns on Texas are 2, 3, 4, 5, 8, 9, 10, 12, 14, 25. Texas was the first ever battleship to be outfitted with 14-inch guns.
 * Wesley Bolin Memorial Plaza, memorial to USS Arizona and World War II, Phoenix, Arizona; one of three previously on Arizona that served on Nevada in World War II.
 * Pennsylvania Military Museum, Boalsburg, Pennsylvania.

Weapons of comparable role, performance and era

 * 14-inch gun M1910 US Army coast defense equivalent
 * EOC 14-inch /45 naval gun contemporary British equivalent
 * Vickers 14-inch/45 naval gun contemporary Vickers-designed Japanese equivalent
 * 340mm/45 Modèle 1912 gun contemporary French naval gun