1-10. Safety, Care and Handling. WARNINGS and CAUTIONS that appear in this manual are of great importance to
your personal safety and the safety of the equipment. Before you attempt to operate, maintain, troubleshoot, or repair
any part of the steering gear system, be sure you review and understand all WARNINGS and CAUTIONS.
Section III. PRINCIPLES OF OPERATION
1-11. General. Port and starboard hydraulic cylinders in the steering gear room are coupled to port and starboard tiller
arms. Stroking of the pistons causes rudder travel. When both pistons are at mid-stroke, the rudders reach a
corresponding hard-over limit. Hydraulic piping delivers pressurized fluid from a vane pump to one side of each piston
and from the other side of each piston back to the fluid reservoir. This loop converts pump displacement to piston stroke.
1-12. Emergency Steering. The steering gear is designed for primary control from the pilothouse, but also includes
control components for emergency operation from the steering gear room. When normal pilothouse 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 pilothouse 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 55-1905-223-24-6) for additional information
about the steering system.