Section 2 Materials and Components

2.1.1 The specified minimum tensile strength of castings and forgings for crankshafts is to be selected within the following general limits:

1. Carbon and carbon-manganese steel castings –

   400 to 550 N/mm²

2. Carbon and carbon-manganese steel forgings (normalised and tempered) -

   400 to 600 N/mm²

3. Carbon and carbon-manganese steel forgings (quenched and tempered) -

   not exceeding 700 N/mm²

4. Alloy steel castings -

   not exceeding 700 N/mm²

5. Alloy steel forgings -

   not exceeding 1000 N/mm²

6. Spheroidal or nodular graphite iron castings -

   370 to 800 N/mm².

2.1.2 Where it is proposed to use alloy castings, micro alloyed or alloy steel forgings or iron castings, details of the chemical composition, heat treatment and mechanical properties are to be submitted for approval.

2.2.1 Materials and components for engines are to be manufactured, tested and documented in accordance with Table 2.2.1 Summary of testing and associated documentation for engine components under a quality control system that is suitable for the actual engine types to be certified by LR. See also Pt 5, Ch 2, 2.2 Testing and inspection 2.2.4 and the applicable requirements specified in the Rules for the Manufacture, Testing and Certification of Materials, July 2022.

2.2.2 Where an LR quality scheme is in place (see Pt 5, Ch 1, 1.3 Alternative approach for product assurance), the testing and documentation requirements in Table 2.2.1 Summary of testing and associated documentation for engine components will be in accordance with a specific LR quality scheme certification schedule identifying the tests, intervention requirements and associated documentation including types of certificates that are to be issued.

2.2.3 The testing and inspection in Table 2.2.1 Summary of testing and associated documentation for engine components is to be documented by the manufacturer (e.g. manufacturer certified materials testing or manufacturer issued NDT report as applicable), except where LR intervention is explicitly required, in which case an LR Component Certificate is to be issued which confirms conformity with the Rule requirements, with tests carried out on either the finished component itself, or on samples taken from earlier stages in the production of the component, as applicable.

2.2.4  Where an LR material certificate is specified for components listed in Table 2.2.1 Summary of testing and associated documentation for engine components, the material is to be from an LR approved manufacturer, and manufactured within the scope of approval of that manufacturer, except where explicitly stated otherwise in other Parts and Chapters of the Rules.

2.2.5 The manufacturer is not exempted from responsibility for any relevant tests and inspections of those parts for which documentation is not explicitly requested by LR. Manufacturers are to be equipped in such a way that all materials and components can be consistently produced to the required standard. This includes production and assembly lines, machining units, special tools and devices, assembly and testing rigs as well as all lifting and transportation devices.

2.2.6 Where Table 2.2.1 Summary of testing and associated documentation for engine components states that a test report is required, this is to be issued by the manufacturer and provided for review by the Surveyor. The report is to identify the samples from the current production batch that have been tested and inspected to confirm that the component complies with all applicable requirements.

2.2.7 Where a manufacturer’s document (test certificate or NDT report) is required in Table 2.2.1 Summary of testing and associated documentation for engine components, this is to be issued by the manufacturer and provided for review by the Surveyor. The document is to comply with the requirements of the Rules for the Manufacture, Testing and Certification of Materials, July 2022, Ch 1, 3.1 General 3.1.3(c) or Ch 1, 5.6 Non-destructive examination reports 5.6.1 as applicable and is to identify the tests and inspections that have been carried out on the finished component itself or, where applicable, on samples taken from earlier stages in the production of the component.

2.2.8 Components and materials not specified in Table 2.2.1 Summary of testing and associated documentation for engine components or of novel design will be specially considered upon submission of their details.

2.3.1 All main and auxiliary engines exceeding 220 kW (300 shp) are to be provided with an alignment gauge which may be either a bridge weardown gauge, or a micro-meter clock gauge for use between the crankwebs. Only one micrometer clock gauge need be supplied for each ship provided the gauge is suitable for use on all engines.

2.4.1  Manufacturers, and external providers of products or services, who carry out autofrettage of engine components, are to apply an approach for product assurance that is accepted by LR.

2.4.2 Documentation for the autofrettage process and the associated approach for product assurance is to be submitted in accordance with Pt 5, Ch 2, 1.4 Submission requirements 1.4.7.

2.4.3 Testing carried out as part of the approach for product assurance is to confirm that the autofrettage process has not detrimentally affected the components and demonstrate that the prescriptive Rule requirements for pressure containment have been met, see Table 2.2.1 Summary of testing and associated documentation for engine components