Figure 6-29.-Hullborne steering system equipment.
the PHM is in the hullborne mode. The location
Now that you have read about the main
of each major equipment item in the hullborne
components of the hull borne propulsion system, let's
steering system is shown in figure 6-29.
take a look at its control system and subsystems.
Primary steering control is provided by a
HULLBORNE CONTROL SYSTEM
hydraulic actuator that vectors the hull borne
steering nozzles in response to position
Whenever the PHM is in the hullborne mode, the
commands from the helm. Additional directional
craft is controlled by the hullborne control system
control is provided by the thrust reversers on
(HBCS). The HBCS consists of the following three
the hullborne propulsory. A bow thruster is
subsystems:
included in this system to allow for improved
low-speed maneuverability and to assist in
1. Hullborne steering system
docking. The capability for strut steering is also
included in this system. In the foils down mode,
2. Heading hold system
for example, the forward strut can be swiveled
for hullborne steering.
3. Hullborne throttle system
Heading Hold System
Operation of the HBCS takes place almost
entirely from the pilothouse, as shown in figures 6-28
The heading hold system provides the PHM
and 6-29. The only HBCS controls located in the EOS
with the capability of automatically maintaining
are the throttle assembly and the throttle transfer
a preset heading while the craft is in either the
module assembly. These assemblies are used in
hullborne or foilborne propulsion mode. The
conjunction with the foilborne control system. Let's
establishes
a
preset
heading
take a brief look at the three subsystems of the
command. A heading error signal is developed as
HBCS.
a difference occurs between the
craft's
gyrocompass and the preset heading command
Hullborne Steering System
from the helmsman. A steering correction signal
is then applied to the ACS or hullborne steering
The hullborne steering system provides
system.
directional control and maneuvering capability while