4. Air-conditioning/chill water system
SCU. Halon maybe actuated by depressing the PRI or
RSV HALON RLSE push button at the PACC or SCU.
5. High-pressure air system
After actuation of Halon, a HALON SYSTEM
6. Ship's service air system
ACTUATED alarm is displayed on the PDU.
7. Internal communication system
Thrust Control System
Now that you have read about the control systems
available at the PACC on the DDG-51 class ships, let's
The thrust control system consists of throttle/pitch
look at those available at the EPCC.
and brake mode control from an MCS control station.
This station can be the PACC, SCU, or the BCU.
Throttle/pitch control is unified under the programmed
EPCC
control and order difference computer program
functions when NORMAL PROGRAMMED MODE is
The EPCC provides centralized control of the ship's
selected. Throttle and pitch controls are separated, and
electric plant. In the DDG-51 class ships, the EPCC
only available at the SCU, when LOCKOUT MANUAL
provides centralized control of the SSGTGs and bus
MODE is selected. Brake mode control is available in
distribution equipment. These features include a panel
both modes. However, brake engagement requires
arrangement of SSGTG controls and display devices in
additional operator action when LOCKOUT MANUAL
three groups, one for each generator. Each group also
is selected. LOCKOUT MANUAL MODE places unit
has controls and indicators for generator circuit breaker
control at the SCU and inhibits control station transfers.
operation and status. Load shedding, shore power
P r o g r a m m e d control is the normal method of
switching, and a visual synchronization presentation for
controlling ship's speed. It simultaneously positions the
all power sources are added features. Limited status of
controllable pitch propeller (CPP) blades and GTE
each air-conditioning plant status is displayed and
power lever angle (PLA) for a propulsion shaft with a
restart controls for each plant are provided. The major
s i n g l e lever. Two programmed control levers are
electrical generation and distribution equipment is
a v a i l a b l e at the PACC. The port and starboard
located in auxiliary machinery room (AMR) No. 1,
programmed control levers at the PACC may be latched
MER No. 2, and the generator room. Each of these
to ensure the shaft horsepower is equal. The
s p a c e s contains one SSGTG and its associated
programmed control levers have a TRIM potentiometer
switchboard.
for fine throttle/pitch adjustments.
An integral AN/UYK-44(V) computer provides for
The programmed control computer program
control and monitoring of the electric plant. The MCS
function is designed for fuel economy. To provide this
requires that the electric plant remain operable if the
fuel economy, the programmed control has been divided
EPCC computer fails. So, many switch functions are
into two operating regions. The first operating region,
hardwired rather than using the DMS. The wiring is
modulate transmission mode, is used for slower ahead
from the EPCC to the controlled device in the generator
and astern thrust settings. The second operating region,
spaces. The required electric plant sensors are also
modulate engine mode, is used for faster ahead and
hardwired to the EPCC panel indicators to provide
astern settings.
status. An EPCC computer failure causes a loss of
electrical plant alarm detection, EPCC DMS
Independent Auxiliaries Systems
communications, and any displays at the PDU.
The independent auxiliaries are systems controlled
The EPCC contains the controls and indicators that
and/or monitored through an SCU, which do not have a
are used to remotely operate and monitor the ship's
direct impact on the propulsion and propulsion auxiliary
service power generation and distribution systems.
Figure 3-10 shows the locations of the control and
equipment. The seawater cooling system pumps are the
indicator panels of the EPCC. In this section, we will
only independent auxiliaries controlled from the PACC.
The independent auxiliaries associated with the MCS
briefly discuss the following control systems operated
from the EPCC:
are as follows:
1. Seawater cooling system
1. SSGTG control and monitoring
2. Sewage and drainage system
2. Electrical distribution monitoring and control
3. Circuit breaker operation
3. Freshwater service
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