scope:

Application

This chapter contains overall requirements common for machinery, systems and components. Detailed requirements are given in the relevant rule chapters in Pt.4.

The rules in this chapter apply to machinery, systems and components for ships and barges for the assignment of main class.

For novel design of a component, a system or the complete arrangement of a vessel, and where the existing rules are not suitable for the purpose, the design can be accepted provided that the overall safety and availability level is found to be equivalent or better than that of the rules. The Society withholds the right to request documentation, tests and trials additional to those specified in the rules.

For such designs an engineering analysis shall be prepared and submitted. The analysis shall as a minimum include the following elements:

1) Thorough definition of the ship, ship systems and components subject to the analysis.

2) Identification of requirements with which the ship or design will not comply.

3) Identification of the possible hazards introduced by the design.

4) Identification of failure modes, consequences of failures and system response (e.g. FMEA) and a test program to verify the conclusions.

5) Determination of the required performance, safety and availability criteria addressed by corresponding requirements applicable for traditional design.

6) Design philosophy and detailed description of the novel design, including a list of the assumptions used in the design and any proposed operational restrictions or conditions.

7) Technical justification demonstrating that the alternative design and arrangements meet the required performance criteria in accordance with the above.

Guidance note:

1) For new technology, recommended practice DNV-RP-A203 can be a suitable basis for such analyses.

2) See also Pt.1 Ch.1 Sec.1 regarding alternatives to detailed requirements in the rules.

Compliance with the rules is required for installations and equipment necessary for performing the main functions given in Pt.1 Ch.1 Sec.1 [1.2].

The rules give system requirements and prescribe minimum requirements for materials, design, manufacture, inspection and testing.

For components to be installed onboard vessels with the class notation Naval, additional requirements given in Pt.5 Ch.13 shall be fulfilled.