Diesel Engine
unit. The speed reduction gearbox drives the propulsor
assembly through an overrunning clutch assembly.
Each hullborne propulsion unit is powered by its
own Mercedes-Benz Model 8V331TC81 diesel engine.
Propulsor
The diesel engine for each unit is located in the diesel
pump and machinery room. Combustion air for the
The hullborne propulsor assembly draws seawater
d i e s e l s and cooling air for the diesel pump and
from a sea chest, accelerates the water, and expels it
machinery room are drawn into the space through a
through a nozzle at the stem. The hullborne propulsor
screened compartment inlet located in the forward end
inlet is a rectangular bellmouth type of penetration in the
of the air trunk. As the diesels draw combustion air from
hull dead rise to which the propulsor is directly attached
this compartment, the air goes through the screens and
The propulsor and inlet ducts are located in the auxiliary
filters and enters the diesel engines. Diesel engine
machinery room.
exhaust gases are collected and vented up and out
Now that you have read about the main components
through the inside of the compartment inlet.
of the hullborne propulsion system, let's take a look at
its control system and subsystems.
Reduction Gear
HULLBORNE CONTROL SYSTEM
The reduction gear assembly for each hullborne
Whenever the PHM is in the hullborne mode, the
propulsion unit is built into the diesel engine for that
craft is controlled by the hullborne control system
Figure 7-27.--HBCS controls at the pilothouse control console.
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