moving the ITC to match the command from the bridge
GTE Control System
displayed by the ITC flashing indicator. This action will
Most of the GTE control and monitoring circuitry
cause the indicator to illuminate steadily. The PACC
functions primarily for normal start-up and shutdown of
operator can also acknowledge the order by moving the
the propulsion gas turbines. All four GTE control and
ITC lever to the new indicated command. This will
monitoring functions can be accomplished at the PACC.
silence the bell and illuminate the indicator steadily.
There are three possible start/stop modes for each GTE
DIGITIZED.-- The digitized EOT provides for
at the PACC: (1) manual, (2) manual initiate, and (3)
communication of nonstandard orders for pitch and
auto initiate. The auto initiate mode will be discussed in
rpm. A nonstandard order is a command for a specified
the plant mode control section of this chapter.
pitch or rpm that is outside the predetermined settings.
The manual control mode consists of operator
If the PACC has throttle control, the operator can set the
generation of the start or stop commands at every step
thumbwheel switches to make the SET and ORDERED
of the sequence. The operator must make sure each step
digital indicators agree. The operator then moves the
is accomplished at the proper time. Sequencing of these
ITC to the ordered position.
manual controls is the same as the time sequential flow
PLANT MODE.-- The plant mode EOT consists of
charts found in the technical manual.
three possible orders: (1) secure, (2) split plant, and (3)
The manual initiate mode consists of starting and
full power. When plant mode is activated, the signal is
stopping the GTM in a semiautomatic mode. In this
sent to the PACC and flashes the indicator for the given
m o d e , the engine will start up or shut down
order and sounds the bell. The operator acknowledges
automatically. The control electronics at the PLCC will
the order by depressing the flashing indicator. When the
automatically sequence the start-up and shutdown steps
new plant condition is achieved, the indicator will
required. This mode is semiautomatic because the brake
illuminate steadily.
and clutch (brake only on the CG-47 class ships)
operation must be done manually.
Throttle and Pitch Control System
The throttle and pitch control system provides
EOT Control System
control of shaft speed and propeller pitch. This control
s y s t e m is an analog control system that uses
The ECSS uses the following three types of EOTs
continuously variable signals to control shaft speed and
for propulsion command information:
propeller pitch.
1. Standard order EOT - Consists of standard
ECSS throttle and pitch control is available at the
engine commands, such as 2/3 back, 1/3 back, stop, 1/3
PLCC, PACC, and SCC. Manual throttle and pitch
ahead, and 2/3 ahead
control is available at the PLCC and PACC. Automatic
or integrated throttle and pitch control (ITC) is available
2. Digitized EOT - Provides rpm commands of 0
at the PACC and SCC. The PACC ITC levers, one for
to 200 rpm in 1-rpm increments and pitch commands of
each shaft, allow single lever automatic scheduled
50 percent to +100 percent in 1 percent increments
control of throttle and pitch. Figure 3-5 shows an overall
3 . Plant mode EOT - Provides commands of
control block diagram of the throttle and pitch control
secured, split plant, and full power
system.
All three EOTs are at the SCC and PACC. All three
Plant Mode Control System
EOTs communicate via the command and control serial
data bus.
The plant mode control electronics is located in the
STANDARD.-- The standard orders are initiated at
PACC. The control works with the start/stop logic at the
the SCC by moving the integrated throttle control (ITC)
PLCC. Auto initiate mode is a part of the plant mode
lever to the commanded standard order position and
control logics. In plant mode control, the operator can
depressing the standard order ALERT pushbutton. This
start up or shut down main engines in both engine rooms
action sends the order to the PACC and PLCC for that
without using the individual GTE start/stop controls.
particular shaft. If the PACC has control, the operator
The plant mode control is normally used only when all
can acknowledge the order by using either one of two
of the following systems are in AUTO:
procedures. The first is by pushing the STD ORDER
1. GTE start/stop control
switch indicator, which silences the EOT bell, and then
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