BL 13.5-inch Mk I – IV naval gun
| Ordnance BL 13.5 inch gun Mk I - IV | |
|---|---|
The forward 13.5-inch (343-mm) gun turret of the battleship HMS Hood | |
| Type | Naval gun |
| Place of origin | United Kingdom |
| Service history | |
| Used by | United Kingdom Kingdom of Italy |
| Production history | |
| Designer | Woolwich |
| Designed | 1880 |
| Variants | Mk I, II, III, IV |
| Specifications | |
| Mass | 67-69 tons barrel & breech |
| Barrel length | 405 inches (10.29 m) bore (30 calibres) |
| Shell | 1,250 pounds (570 kg) |
| Calibre | 13.5-inch (342.9 mm) |
| Muzzle velocity | 2,016 feet per second (614 m/s) |
| Effective firing range | 12,000 yards (11,000 m) |
The BL 13.5 inch naval gun Mk I ("67-ton gun") was Britain's first successful large breechloading naval gun, initially designed in the early 1880s and eventually deployed in the late 1880s. Mks I - IV were all of 30 calibres length and of similar construction and performance.