5-inch/54-caliber Mark 45 gun
The 5" (127 mm)/54 caliber (Mk 45) lightweight gun is a U.S. naval artillery gun mount consisting of a 5 in (127 mm) L54 Mark 19 gun on the Mark 45 mount. It was designed and built by United Defense, a company later acquired by BAE Systems Land & Armaments, which continued manufacture.
| Mark 45 5-inch/54-caliber lightweight gun | |
|---|---|
5-inch/62 caliber Mark 45 Mod 4, in flat-panel gun turret, test firing on USS Forrest Sherman | |
| Type | Naval gun |
| Place of origin | United States |
| Service history | |
| In service | 1971–present
|
| Used by | See Operators |
| Production history | |
| Designed | 1968 |
| Manufacturer | United Defense (now BAE Systems Land & Armaments) |
| Produced | 1971 |
| Specifications (Mod 2) | |
| Mass | 21,691 kg (47,820.5 lb) |
| Length | 8.992 m (29 ft 6.0 in) |
| Barrel length | 6.858 m (22 ft 6.0 in) Rifling: 5.82 m (19 ft 1 in)
|
| Shell | 127 x 835mm .R Conventional: 31.75 kg (70.0 lb) |
| Caliber | 54 caliber |
| Elevation |
|
| Traverse |
|
| Rate of fire | 16–20 rounds per minute automatic |
| Muzzle velocity |
|
| Effective firing range | 13 nmi (24.1 km) or 20 nmi (37.0 km) (Mod 4) |
The latest 62-calibre-long version consists of a longer-barrel L62 Mark 36 gun fitted on the same Mark 45 mount. The gun is designed for use against surface warships, anti-aircraft and shore bombardment to support amphibious operations. The gun mount features an automatic loader with a capacity of 20 rounds. These can be fired under full automatic control, taking a little over a minute to exhaust those rounds at maximum fire rate. For sustained use, the gun mount would be occupied by a six-person crew (gun captain, panel operator, and four ammunition loaders) below deck to keep the gun continuously supplied with ammunition.