Section 7 Testing and trials

7.1.1 The requirements of the Rules relating to the testing of Class 1 pressure vessels, piping, and related fittings including hydraulic testing apply.

7.1.2 After installation on board the vessel the steering gear is to be subjected to the required hydrostatic and running tests.

7.1.3 Each type of power unit pump is to be subjected to a type test. The type test shall be for a duration of not less than 100 hours, the test arrangements are to be such that the pump may run in idling conditions, and at maximum delivery capacity at maximum working pressure. During the test, idling periods are to be alternated with periods at maximum delivery capacity at maximum working pressure. The passage from one condition to another should occur at least as quickly as on board. During the whole test no abnormal heating, excessive vibration or other irregularities are permitted. After the test, the pump is to be opened out and inspected. Type tests may be waived for a power unit which has been proven to be reliable in marine service.

7.2.1 The steering gear is to be tested on the trial trip in order to demonstrate to the Surveyor's satisfaction that the requirements of the Rules have been met. The trial is to include the operation of the following:

1. The steering gear:
   • For the main steering gear trial, the propeller pitch of controllable pitch propellers is to be at the maximum design pitch approved for the maximum continuous ahead RPM;
   • If the ship cannot be tested at the deepest draught, then the loading condition can be accepted on the conditions that either the rudder is fully submerged (at zero speed waterline) and the vessel is in an acceptable trim condition, or the rudder torque at the trial loading condition has been reliably predicted and extrapolated to the full load condition, to the satisfaction of the Administration. In any case, for the main steering gear trial, the speed of the ship corresponding to the maximum continuous revolutions of main engine and maximum design pitch applies;
   • Depending on the steering system type the performance required by the following is to be demonstrated:
     1. Where a rudder type steering system is fitted see
        • Pt 5, Ch 19, 2.2 Performance requirements for rudder-type steering systems 2.2.1.(a) and
        • Pt 5, Ch 19, 2.2 Performance requirements for rudder-type steering systems 2.2.1.(b)
     2. Where a podded propulsion steering system is fitted see
        • Pt 5, Ch 9, 5.6 Steering system 5.6.4.(a) and
        • Pt 5, Ch 9, 5.6 Steering system 5.6.5.(b)
     3. Where a water jet steering system is fitted see
        • Pt 5, Ch 16, 3.7 Nozzle/steering arrangements 3.7.3.(a), and
        • Pt 5, Ch 16, 3.7 Nozzle/steering arrangements 3.7.4.(b)
     4. Where an azimuth thruster steering system is fitted see
        • Pt 5, Ch 20, 2.1 General 2.1.4.(a)
        • Pt 5, Ch 20, 2.1 General 2.1.5.(b)

2. The steering gear power units, including transfer between steering gear power units;

3. The isolation of one power actuating system, checking the time for regaining steering capability;

4. The hydraulic fluid recharging system;

5. The emergency power supply required by Pt 5, Ch 19, 6.1 General 6.1.2;

6. The steering gear controls, including transfer of control and local control;

7. The means of communication between the steering gear compartment and the wheelhouse, also the engine room, if applicable;

8. The alarms and indicators;

9. Where the steering gear is designed to avoid hydraulic locking this feature shall be demonstrated.

Test items Pt 5, Ch 19, 7.2 Trials 7.2.1.(d), Pt 5, Ch 19, 7.2 Trials 7.2.1.(g), Pt 5, Ch 19, 7.2 Trials 7.2.1.(h) and Pt 5, Ch 19, 7.2 Trials 7.2.1.(i) may be effected at the dockside.

7.2.2 The ability of the machinery to reverse the direction of thrust in sufficient time and bring the ship to rest within a reasonable distance from maximum ahead service speed is to be demonstrated and recorded.

7.2.3 The stopping times, ship headings and distances recorded on trials, together with the results of trials to determine the ability of ships having multiple propulsion/steering arrangements to navigate and manoeuvre with one or more of these devices inoperative, shall be available on board for the use of the Master or designated personnel.