(1) Reservoir Sight Gauge (FIGURES 1-6 and 1-7). This gauge has spring return knobs above and below the
sight glass. To read the oil level, pull and hold both knobs outward while oil finds its level within the glass. Take a
reading, then release both knobs. The gauge reads HIGH when the reservoir contains 30 gallons and LOW when the
reservoir contains 10 gallons.
containing a floating magnet and a reed switch. When the oil level drops below the set point of the probe, the magnet
trips the reed switch and energizes an alarm on the control panel in the pilothouse. Mountings and electrical connections
for each probe are in each uniblock manifold. The alarm sounds when only 15 gallons are left in the reservoir.
(3) Reservoir Inlet Line Strainer. The 100-wire mesh strainer, rated at a 20 gpm flow, traps contaminated
particles over .010 inch in diameter. One unit is installed in each reservoir on the suction line to the hydraulic pump.
The strainer element can be removed for periodic cleaning or be replaced when it is no longer serviceable.
c. Pumpset. The pumpset generates hydraulic energy to power the steering gear. The pumpset draws hydraulic
fluid from integral reservoirs and circulates it under pressure through system piping. In each pumpset, a 10horsepower
electric motor drives a vane-type hydraulic pump displacing 9.5 gpm at the nominal 930 psi charge pressure. Normally,
only one pumpset powers the steering gear. The other is considered a standby. Each pump discharges into a separate
four-way solenoid-controlled directional valve that is responsive to electrical commands from the pilothouse. On
command, the valve diverts fluid into the starboard and port actuating cylinders, moving the tillers in the direction
ordered to control the rudders. In the absence of any signal, a lockvalve applies a fluid lock to the pistons in both
actuators. A threeposition DARBS (double acting relief/ bypass/shutoff) valve protects the system from overpressure
damage if rudder movement is obstructed or a malfunction occurs.
(1) Return Line Filter(FIGURES 1-9 and 1-11). This 30-gpm rated filter is installed in the suction line to each
vane pump. The filter head diverts hydraulic oil through a spin-on disposable cartridge rated for 10-micron filtration. The
head design incorporates the oil inlet port, the oil outlet port, a vacuum gauge, and an internal bypass valve, in addition
to mounting dogs for the head and the mounting flange for the spin-on cartridge. A gauge reading of 10 inches of
mercury (5 psi) indicates that the cartridge should be changed. The bypass opens somewhat above this value to
safeguard the pump from cavitation.
(2) Pump Motors. Identical I O-horsepower electric motors drive the two vane pumps at 1800 rpm. The
motors operate on 230-Vac, 3-phase, 60-Hz power from the motor control switchboard located in the engine control
room. Backup power is provided from the emergency switchboard located in the emergency generator room. The shafts
of each motor and pump are directly coupled.
Change 1 1-12