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TM 55-1905-223-24-9
Section V. INTERMEDIATE GENERAL SUPPORT MAINTENANCE PROCEDURES
4-7. 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 and Chapter 3, Section V.)
(1) Steering System Valves. In order to move the rudders either right or left using a pump that operates
continuously in the same direction, a directional valve is installed between the pump and the pistons to stop, start, or
reverse the flow. The valve has two solenoids, one for the right rudder and the other for the left. When neither solenoid
is energized, springs position the valve in neutral, cutting off flow. In each pumpset, a relief valve between the pump and
the solenoid valve limits operating pressure to 930 psi.
(2) Emergency Steering. 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.
NOTE
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 551905-223-10) and
the bowthruster water jet maintenance manual (TM 55-1905-223-24-6) for additional information
about the steering system.
b. General Instructions. Repair at this level consists of replacement of components within steering gear sub-
assemblies. Procedures for disassembly, inspection, repair, assembly, and adjustment are detailed in the following
paragraphs. See also general instructions in Chapter 3, Section V.
4-3
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