The EOC 10-inch 45 calibre gun were various similar 10-inch naval guns designed and manufactured by Elswick Ordnance Company to equip ships they built and/or armed for several countries before World War I.
Elswick supplied later, more powerful "Pattern W" models of its 10 inch 45-calibre guns for the armoured cruisers. In Italian service these were known as the Cannone da 254/45 A Modello 1906.
The Kashima had a secondary armament of four single-gun turrets positioned on each side of the ships superstructure. In Japanese service these guns were known as 10-inch/45 Type 41 naval guns.
Elswick supplied 5 of their 10-inch 45-calibre guns for use on the battleship Constitución that they were building for Chile. Britain took the ship over in 1903 as HMS Swiftsure, and the guns were designated BL 10 inch Mk VI in UK service. These guns fired a projectile using of cordite MD propellant.