3.1.1 The following Sections are to be complied with for all Ice Classes, where applicable. Alternative arrangements to attain similar performance will be considered.
3.1.2 All components of the main propulsion system are to be of steel or other approved ductile material.
3.2.1 Propellers and propeller blades are to be of cast steel or copper alloys and are to be manufactured, tested and certified in accordance with Ch 4, 1 General requirements, Ch 4, 5 Castings for propellers and Ch 9, 1 Castings for propellers of the Rules for Materials respectively.
3.2.2 For steel propellers, the elongation of the material used is to be not less than 15 per cent for a test piece length of 5d. Charpy impact tests are to be carried out in accordance with the requirements of the Rules for the Manufacture, Testing and Certification of Materials, July 2022.
3.2.3 Cast steel load transmitting components of controllable pitch mechanisms are to be manufactured, tested and certified in accordance with the requirements of Ch 4, 5 Castings for propellersof the Rules for Materials.
3.2.4 Forged steel load transmitting components of controllable pitch propellers are to be manufactured, tested, and certified in accordance with Ch 5, 1 General requirements and Ch 5, 2 Forgings for ship and other structural applications of the Rules for Materials. Impact tests are to be carried out at minus 10°C and the average energy value is to be not less than 20 J.
3.2.5 Spheroidal cast iron load transmitting-components of controllable-pitch mechanisms are to be manufactured, tested and certified in accordance with the requirements of Table 7.3.5 Mechanical properties: special qualities in Ch 7, 3 Spheroidal or nodular graphite iron castings of the Rules for Materials.
3.3.1 The sea inlet and overboard discharge valves which are situated at or below the maximum Load Line, are to be provided with low pressure steam or compressed air connection for clearing purposes, see Pt 5, Ch 13 Ship Piping Systems. Provisions need not be applied for the discharge from the main engine and central cooling water system for first-year and multi-year ice classes.
3.3.2 When steam is not available for clearing, it is recommended that arrangements be made for supplying water for machinery cooling purposes by circulating from ballast tanks(s) of adequate capacity, preferably situated in the double bottom. Such tank(s) must be used only for storage of water ballast or fresh water.
3.4.1 In motor ships where clearing steam is not available, fire pumps are to be provided with suctions from a suitable sea water inlet which is maintained ice-free at all times.
3.4.2 At least one of the fire pumps is to be connected to a sea chest which is provided with de-icing arrangements.
3.5.1 Sea inlets for the cooling water system are to be provided with arrangements to maintain ice free cooling water arrangements as given by IMO MSC/Circular.504 – Guidance on Design and Construction of Sea Inlets Under Slush Ice Conditions – (28 April 1989) or by the Finnish Swedish Ice Class Rules. Alternative arrangements will be considered, such as by circulating engine cooling water via designated tanks where heat balance calculations have demonstrated that the engines are capable of operating at their maximum continuous rating.
3.5.2 For electric propulsion systems, the total engine output for propulsion provided by generator sets/central generation system is to be based on the calculation with one set out of action, see Pt 6, Ch 2, 16 Electric propulsion.