Page 254 - Introduction to Marine Engineering

230 Steering gear

the actuator. The self closing valves are fitted on the inlet and outlet
ports of the actuator and open under oil pressure against the action of a
spring. Where an oil pressure loss occurs in one circuit the valves will
immediately close under the action of their springs. A low tank level
alarm will sound and the other pump can be started. This pump will
build up pressure, open the valves on its circuit and the steering gear can
immediately operate.

Steering gear testing

Prior to a ship's departure from any port the steering gear should be
tested to ensure satisfactory operation. These tests should include:
1. Operation of the main steering gear.
2. Operation of the auxiliary steering gear or use of the second pump
which acts as the auxiliary.
3. Operation of the remote control (telemotor) system or systems from
the main bridge steering positions.
4. Operation of the steering gear using the emergency power supply.
5. The rudder angle indicator reading with respect to the actual rudder
angle should be checked.
6. The alarms fitted to the remote control system and the steering gear
power units should be checked for correct operation.

During these tests the rudder should be moved through its full travel
in both directions and the various equipment items, linkages, etc.,
visually inspected for damage or wear. The communication system
between the bridge and the steering gear compartment should also be
operated.