5"/54 caliber Mark 45 gun

The 5-Inch/54-caliber (Mk 45) lightweight gun is a modern U.S. naval artillery gun mount consisting of a 5-inch (130-millimetre) L54 Mark 19 gun on the Mark 45 mount. Originally designed and built by United Defense, it is now manufactured by BAE Systems Land & Armaments after the former was acquired. The latest 5-inch/62-caliber 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-man crew (gun captain, panel operator, and four ammunition loaders) below deck to keep the gun continuously supplied with ammunition.

5"/54 caliber Mark 45 gun
Class Vehicle
Type Towed Artillery
Manufacturer BAE Systems Land & Armaments
Origin United States of America
Country Name Origin Year
United States of America 1971
Country Name Operational Year Retirement Year
Australia View
Denmark View
Greece View
Japan View
Korea View
Spain View
Turkey (Ottoman Empire) View
United States of America View
United States of America View
Taiwan View
New Zealand View
ManufacturerName Production From Production To Quantity
BAE Systems Land & Armaments 1971 View

Development started in the 1960s as a replacement for the 5"/54 caliber Mark 42 gun system with a new, lighter, and easier to maintain gun mounting. In USN use, the Mark 45 is used with either the Mk 86 Gun Fire Control System or the Mk 160 Gun Computing System. Since before World War II, 5 in has been the standard gun caliber for U.S. Naval ships. Its rate of fire is lower than the British 4.5-inch (113 mm) gun, but it fires a heavier 5" shell which carries a larger burst charge that increases its per-shell effectiveness against aircraft.

Type Naval gun
Place of origin United States
Service history
In service Mod 0: 1971
Mod 1: 1980
Mod 2: 1988
Mod 4: 2000
Used by See Operators
Production history
Designed 1968
Manufacturer United Defense (now BAE Systems Land & Armaments)
Produced 1971
Weight Mod 2: 21,691 kg(47,820.5 lb)
Mod 4: 28,924 kg (63,766.5 lb)
Length Mod 2: 8.992 m (29 ft 6.0 in)
Mod 4: 10.008 m (32 ft 10.0 in)
Barrel length Mod 2: 6.858 m (270.0 in)
Rifling: 5.82 m (229 in)
8,000 rounds (barrel life)
Mod 4: 7.874 m (310.0 in)
Rifling: 6.836 m (269.1 in)
7,000 rounds (barrel life)
Shell Conventional: 31.75 kg (70.0 lb)
Caliber 5.0 inches (127.0 mm)
Barrels Single barrel (progressive RH parabolic twist)
Elevation -15° – +65°
Maximum elevation rate: 20°/sec
Traverse ±170° from centerline
Maximum traversing rate: 30°/sec
Rate of fire 16–20 rounds per minute automatic
Muzzle velocity Mod 2: 2,500 ft/s (762.0 m/s)
Mod 4: 2,650 ft/s (807.7 m/s)
1,500 ft/s (457.2 m/s) reduced charge for defilade fire or illumination rounds
Effective firing range 13 nmi (24.1 km)
Feed system 600 rounds (Ticonderogaclass)
680 rounds (Arleigh Burkeclass)
475–500 rounds (Other classes)

End notes