Section V. INTERMEDIATE DIRECT SUPPORT MAINTENANCE PROCEDURES
3-7. General. The following paragraphs give principles of operation applicable to this maintenance chapter and overall
instructions for disassembly, cleaning, and assembly procedures.
a. Principles of Operation. (Also see Chapter 1, Section III). The dual pumpset has lockvalves between the
solenoid valves and the actuating cylinders. This valve prevents rudder movement in the absence of a rudder
command. To protect this loop from overpressurization damage in case a hard object strikes the rudders, a DARBS
valve is installed to open at 1160 psi. The steering gear is designed for primary control from the pilot house, but also
includes control components for emergency operation from the steering gear room. When normal pilot house steering
control is disabled, control can be switched to the steering gear room using one of the two local control units bulkhead
mounted near the pumpsets. Unit A controls pumpset A and unit B controls pumpset B. The control transfer switch is set
to LOCAL to provide rudder control. Communication with the pilot house is also required for heading information. On
the panel of each controller is a dip switch that will move the rudders right or left when pressed off neutral in either
direction. Rudder travel continues while the switch is held in either direction, unless a hard-over stop is reached. Each
local control unit has a rudder angle indicator above the dip switch.
When maneuvering the ship in close quarters, the bowthruster water jet will normally be operated in
conjunction with the steering gear. Refer to the LCU Operator's Manual (TM 55-1905-223-10) and
the bowthruster water jet maintenance manual (TM 55-1905-22324-6) for additional information
about the steering system.
b. General Instructions. Before beginning disassembly of any steering gear component, a thorough inspection
should be made to determine its overall condition and whether, in fact, it should be repaired. Many times it is better to
replace the component with a new one rather than spend time and effort to repair it. When you find you need to repair
the component, it should be disassembled carefully (see a. below) and all parts should be cleaned.
(1) Disassembly. Information written down during disassembly can save a lot of time during assembly.
(a) Mark or identify the location and position of mounting components when you remove them.
(b) When removing capscrews, record type, length, and location. This will make sure you replace the
right ones in the right order when you assemble the equipment.
(c) Tag electrical wires, tubing, and bearing position to ensure correct assembly.