Section 6 Trials
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Inland Waterways Ships, July 2022 - Part 5 Main and Auxiliary Machinery - Chapter 1 General Requirements for the Design and Construction of Machinery - Section 6 Trials

Section 6 Trials

6.1 Inspection

6.1.1 Tests of components and trials of machinery, as detailed in the Chapters giving the requirements for individual systems, are to be carried out to the satisfaction of the Surveyors.

6.2 Trials

6.2.1 For all types of installation, the trials are to be of sufficient duration, and carried out under normal manoeuvring conditions, to prove the machinery under power. The trials are also to demonstrate that any vibration which may occur, within the operating speed range, is acceptable.

6.2.2 The trials are to include demonstrations of the following:

  1. The adequacy of the starting arrangements to provide the required number of starts of the main engines.

  2. The capability of the machinery to reverse the direction of thrust of the propeller in sufficient time, under normal conditions, to bring the ship to rest from maximum ahead service speed.

6.2.3 Where controllable pitch propellers are fitted, the free route astern trial is to be carried out with the propeller blades set in the full pitch astern position. Where emergency manual pitch setting facilities are provided, their operation is to be demonstrated to the satisfaction of the Surveyor.

6.2.4 In geared installations, prior to full power trials, the gear teeth are to be suitably coated to demonstrate the contact markings, and on conclusion of the trials all gears are to be opened up sufficiently to permit the Surveyors to make an inspection of the teeth. The marking is to indicate freedom from hard bearing, particularly towards the ends of the teeth, including both ends of each helix, where applicable. The contact is to be not less than that required by Pt 5, Ch 3, 4.2 Accuracy of gear cutting and alignment or Pt 5, Ch 3, 5.2 Meshing tests, as applicable.

6.2.5 The following information is to be available on board for the use of the Master and designated personnel:

  • The results of trials to determine stopping times, ship headings and distance;
  • For ships having multiple propellers, the results of trials to determine the ability to navigate and manoeuvre with one or more propellers inoperative.

6.2.6 Where the ship is provided with supplementary means for manoeuvring or stopping, such as a bow thruster, the effectiveness of such means are to be demonstrated.

6.2.7 All trials are to be to the Surveyor’s satisfaction.


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