5"/54 Caliber Mark 45 Gun - Variants

Variants

• Mod 0: used mechanical fuze setter. Two piece rifled construction, with replaceable liner
• Mod 1: electronic fuze setter replaces the mechanical one. Made with a unitary construction barrel, which has a life span approximately twice that of the Mark 42 gun.
• Mod 2: export version of Mod 1, but now used in the US Navy
• Mod 3: same gun with a new control system; never put into production
• Mod 4: longer 62 caliber barrel (versus Mod 1 & 2's 54 caliber) for more complete propellant combustion, higher velocity, greater range at +20 nautical miles (37 kilometres; 23 miles) and thus more utility for land attack.

Special note

In sustained firing operations (Mode III), the gun is manned by a three-man crew all located below decks. These are a gun captain, a panel operator, and ammunition loader. In fully automatic non-sustained firing operations (Mode IV), the gun can be fired without any personnel inside the mount. However, sustained fire is limited to the capacity of the automatic loader (20 rounds). This means that there will be no-one at control panel for the gun to safe the weapon when having to fallback to verbal cease fire to the gun crew.