cooling air to and from the GTE. The inlet
cooling airflow to the engine for normal
operation. A controller provides for manual or
systems have inlet louvers, demisters, blow-in
automatic operation by a selector switch on the
doors, silencers, cooling airflow modulators, fans,
controller door. When in manual, you can use a
and a fire damper. The exhaust systems contain
silencers and IR suppression systems. The exhaust
push button to energize a solenoid and release the
gas is routed through waste heat boilers (WHBs)
blow-in door. When in automatic, the solenoid
is energized by action of a pressure switch. This
switch is set to operate at about 8 inches of water
(in.H2O) differential pressure. Indication and
alarm of DUCT PRESS LO are given at the
The intake ducts are rectangular structures
propulsion local operating equipment (PLOE) and
attached to the enclosure by a flexible rubber
the propulsion and auxiliary machinery control
equipment (PAMCE) consoles. Once open, the
doors must be closed manually.
through a common duct, but separate before
entering the enclosure. The ducts for the No. 1
SILENCERS. --The vane-type silencers have
and No. 2 engines are located on the inboard side
sound-deadening material encased in a perforated,
of the exhaust stacks. Air enters the ducts through
stainless steel sheet. They are mounted vertically
louvers mounted in the side of the stack. It flows
in the duct between the demisters and the cooling
through mesh pad demisters and silencers into the
module inlet plenum and into the engine inlet. The
cooling air splits off just before the flexible boot
ANTI-ICING. --The anti-icing system is
on top of the inlet plenum. It is routed to the aft
similar to that in the main engine inlet ducts. Hot
end of the enclosure through another flexible
bleed air from the engine is discharged into the
inlet duct. There it mixes with the inlet air and
The intake air plenum for the No. 3 GTGS
raises the temperature above the freezing point.
is located on the 01 level, starboard side, aft of
Bleed air flow is regulated as a function of
the missile launcher area. Air enters a vertical
upstream temperature versus a fixed temperature.
bellmouth and flows into the No. 3 generator.
This maintains an inlet temperature of about 38°F
This plenum serves as a green water trap. It allows
when anti-icing is selected. This temperature is
any large quantities of water to drain through slots
enough to prevent the formation of ice. It also
in the deck combing. The air then flows through
melts any ice, sleet, or snow entrained in the air.
demisters into the No. 3 generator intake room.
The bulkhead between these two compartments
Module Cooling System
air flow through separate ducts from the intake
The module cooling system has a duct, a flow
room to the module.
modulator, an axial fan (two fans on the model
139), a fire damper, an air silencer, and a ceiling-
LOUVERS.--The intake duct inlets for the
mounted baffle within the module.
No. 1 and No. 2 engines have louvers similar to
the main engine inlet louvers. Like the main
modulator is located in the cooling duct between
engine louvers, they are designed and arranged
the engine intake duct and the fan. It controls the
to shed sea spray. Because of the vertical flow inlet
flow of air to the module enclosure based on the
design, the No. 3 engine duct inlet has no louvers.
enclosure air temperature. When the enclosure
temperature increases to 180°F, the high-
DEMISTERS. --The demisters are mesh pads.
temperature set point contacts of the module-
They are similar to those in the main engine inlet.
mounted thermostat will close. This causes the
They are arranged vertically behind the louvers.
flow modulator motor to rotate the modulating
Moisture separated from the air collects in
blade-type vanes to the full-open position. When
scuppers under the demisters and is drained
the enclosure temperature decreases to 170°F, the
low-temperature set point contacts will close. This
causes the flow modulator motor to rotate the
BLOW-IN DOORS.--A single blow-in door
modulating vanes back to the half-open position.
is located in each inlet below the demisters. Their
The modulator is not used on the model 139
purpose is to bypass the demisters if they become
clogged. This permits enough combustion and