Figure 7-18.--Patro1 combatant missile (hydrofoil) (PHM).
the hullborne mode, a water jet nozzle pivots in response
6. Auxiliary subsystems
to an operator command from the helm to provide
I n the following paragraphs, we will briefly
s t e e r i n g and reversing functions. A bow thruster
describe these systems and how they work to propel and
p r o v i d e s for close-in maneuvering and docking.
control the craft.
Consequently, the hullborne mode is used for any type
of close maneuvering, such as docking or reversing the
craft's direction. When the craft is in the foilborne mode,
a control system consisting of the helm, throttle, and an
The PHM has two complete and separate main
automatic control system (ACS) provides continuous
propulsion systems: (1) the foilborne system and (2) the
dynamic control during all foilborne operations. By
hullborne system. As its name implies, the foilborne
providing trim and attitude control, automatic banking
propulsion system propels the ship in the foilborne
i n turns, and seaway disturbance alleviation, the
mode. In addition, the foilborne system can propel the
ship in the hullborne mode, either with the foils extended
foilborne control system makes it possible for the PHM
or retracted. The hullborne propulsion system, however,
to achieve its desirable riding qualities and fast speeds.
can propel the ship only in the hullborne mode, either
The foilborne control surfaces include the trailing edge
with the foils up or down. The machinery arrangement
flaps on each of the foils and the swiveled forward strut
for both the foilborne and hullborne propulsion systems
which acts as a rudder. (See fig. 7-19.) In the following
is shown in figure 7-19.
paragraphs, we will get a closer look at both the
hullborne and foilborne propulsion systems. Let's first
B o t h foilborne and hullborne operations are
look at the foilborne system.
controlled from a common helm. When the PHM is in