| EOC 12 inch 45-calibre naval gun 12"/45 41st Year Type | |
|---|---|
 41st Year Type on Mikasa | |
| Type | Naval gun |
| Place of origin | United Kingdom |
| Service history | |
| In service | 1906–1952 |
| Used by | United Kingdom Brazil Empire of Japan |
| Wars | World War I |
| Production history | |
| Designer | Elswick Ordnance Company |
| Specifications | |
| Barrel length | Bore 45 feet (13.716 m) (45 cal) |
| Shell | 850 pounds (385.6 kg) |
| Calibre | 12-inch (304.8 mm) |
| Muzzle velocity | 2,700 feet per second (823 m/s) - 2,800 feet per second (853 m/s) |
| Maximum firing range | 18,850 yards (17,240 m) |
The EOC 12 inch 45 calibre gun were various similar 12-inch wire-wound naval guns designed and manufactured by Elswick Ordnance Company to equip ships that the parent company Armstrong Whitworth built and/or armed for several countries before World War I.