Figure 6-16.The 5"/54 Mk 45 Mod 0, general arrangement.
ships. The Mk 45 (fig. 6-16) is a fully automatic,
dual-purpose, lightweight gun mount capable of firing
the full range of 5"/54 projectiles, including
rocket-assisted projectiles (RAPs), at a rate of 17 to 20
rounds per minute. During normal operation the loading
system (fig. 6-17), like the Mk 42, is operated locally by
the mount captain; the gun laying, fuze setting, and
firing orders are generated by the FCS. The gun may be
positioned locally from the EP2 panel for maintenance
The only manned positions on the Mk 45 gun during
normal operations are the mount captain, who operates
the gun from the EP2 panel, and the loader room crew.
The gun mount itself, unlike the Mk 42, is unmanned.
There is no local firing position, as with the Mk 42
OMC. The mount power distribution panel, EP1, is also
the mount captain's responsibility.
The loader drum holds a total of 20 complete rounds
of ammunition. Before an operation, the loader crew
will load the drum, through the lower hoist, with 20
rounds of one type of ammunition. If during the
operation another type of round is desired, the mount
captain, using local controls, can allow the system to
operate under alternate loading. This mode allows the
loaders to hand-feed the different types of ammunition
into the loading system, which automatically transfers
only these rounds to the breech for firing. Depending
upon the tactical situation, the loader crew may be
required to load several different types of ammunition
in a short time. The loader crew must, therefore, be able