Figure 6-9.-Steering yoke and controls.
STEERING YOKE. The relative location of the
and assembly port and one The bow thruster control
system consists of two bow thrusters (one starboard),
steering yoke in the operator control station is shown
the steering yoke assembly, and the associated
in figure 6-5. The components and controls of the
electrical and hydraulic operating mechanism. The
steering yoke are shown in greater detail in figure 6-
physical arrangement of these components and
9. The operator at the steering control station uses
assemblies is shown in figure 6-8. The bow thrusters
the steering yoke to control the direction of the bow
provide thrust for the craft. The controls and
thrusters. The steering yoke will turn 45 in either
operating mechanisms allow the control station
direction.
operator to control the rotation of the bow thrusters
to achieve the desired directional thrust. Basically,
FORWARD/REVERSE SWITCH. This switch
the control station operator uses the steering yoke in
allows the operator to select the direction in which
the steering control assembly to turn the craft right
the bow thrusters apply thrust. The switch is located
or left, respectively. Turning the yoke left causes the
on the steering yoke. (See fig. 6-9) The switch allows
craft to turn left, while turning the yoke right causes
an electrical signal to pass through the CSEP to the
the craft to turn right. The steering yoke contains
bow thruster drive mechanism to position the bow
potentiometers that detect yoke movement and send
thruster as ordered.
electrical signals through the CSEP to the hydraulic
operating mechanism.
BOW THRUSTER DRIVE MECHANISM. The
bow thruster drive mechanism works to move the
Like the rudder control system, the bow thruster
bow thrusters to the position ordered by the operator.
control system uses hydraulic power to turn the bow
When the yoke is turned, it positions a potentiometer
thrusters. A system of pumps, flow control valves,
and sends an electrical signal to a mode and bias
and piping supplies hydraulic power to the bow
amplifier in the CSEP. The signal then goes to the
thruster wheel units and lift fan cushion vanes.
bow thruster drive mechanism to position the bow
When the operator turns the yoke, electrical signals
thruster. The bow thruster turns, positioning a
are generated and routed through the CSEP to the
feedback potentiometer, and sends a feedback signal
bow thruster actuators. The basic components of the
to the CSEP. When the feedback signal equals the
bow thruster control system are the steering yoke,
command signal, the bow thruster is in the desired
forward/reverse
switch,
bow
thruster
drive
position.
mechanism, turning vanes, channel selector switch,
and indicators.
