Section 7 Testing and trials
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Offshore Units, July 2022 - Part 5 Main and Auxiliary Machinery - Chapter 19 Steering Gear - Section 7 Testing and trials

Section 7 Testing and trials

7.1 Testing

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 unit, 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 and 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 Trials

7.2.1  The steering gear is to be tried out 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, including demonstration of the performances required by Pt 5, Ch 19, 2.1 General 2.1.2.(b) and Pt 5, Ch 19, 2.1 General 2.1.3.(b):
    • 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 unit cannot be tested at the deepest draught, alternative trial conditions may be specially considered. In this case, for the main steering gear trial, the speed of the ship unit corresponding to the maximum continuous revolutions of the main engine should apply:
  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 6.1.1;
  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.


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