Section 3 Machinery arrangements

3.1.1 For PSMR, PSMR★, PMR and PMR★ notations, independent main propulsion systems are to be provided so that at least 50 per cent of the installed prime mover capacity and not less than 50 per cent of the installed propulsion systems will continue to be available in the event of a single failure of a system or item of active equipment, see Vol 3, Pt 1, Ch 3, 1.1 General 1.1.4. In the event of a single failure in equipment, the remaining system(s) is to be capable of maintaining a manoeuvring speed and, for PSMR and PSMR★ notations, give adequate manoeuvring capability, see Vol 3, Pt 1, Ch 3, 1.2 Documentation required for design review 1.2.4.

3.1.2 For PMRL, PSMRL, PMRL★ and PSMRL★ notations, independent main propulsion systems are to be provided so that the ship will retain the ability to use the available installed prime mover capacity and installed propulsion systems following a single failure of a system or item of equipment. In the event of a single failure in equipment, the remaining system(s) is to be capable of maintaining a manoeuvring speed of not less than 7 knots and, for PSMRL and PSMRL★ notations, give adequate manoeuvring capability, see Vol 3, Pt 1, Ch 3, 1.2 Documentation required for design review 1.2.4.

3.2.1 For PSMR, PSMR★, SMR and SMR★ notations, independent steering systems for manoeuvring the ship are to be installed, such that steering capability will continue to be available in the event of any of the following:

1. Single failure in the steering gear equipment.

2. Loss of power supply or control system to any steering system.

3.3.1 The main busbars of the switchboard supplying the propulsion machinery and other Mobility and/or Ship Type systems are to be capable of being isolated by a multi-pole linked circuit breaker, disconnector, or switch-disconnector into at least two independent sections.

3.3.2 In the event of the loss of one section or failure of the power supply from one generator, there is to be continuity of sufficient electrical power to supply Mobility and/or Ship Type systems such that the available installed prime mover capacity and installed propulsion systems will continue to have the ability of functioning at their operational capability where PSMRL, PSMRL★, PMRL and PMRL★ notations are required. See Vol 3, Pt 1, Ch 3, 3.2 Steering machinery 3.2.1 for steering machinery requirements.

3.3.3 In the event of the loss of one section or failure of the power supply from one generator, there is to be continuity of sufficient electrical power to supply Mobility and/or Ship Type systems such that at least 50 per cent of the installed prime mover capacity and not less than 50 per cent of the installed propulsion systems will continue to be available where PSMR, PSMR★, PMR and PMR★ notations are required. See Vol 3, Pt 1, Ch 3, 3.2 Steering machinery 3.2.1 for steering machinery requirements.

3.3.4 For ships capable of operating with one service generator connected to the switchboard, arrangements are to be such that a standby generator will automatically start and connect to the switchboard on loss of the service generator. Sequential starting of Mobility and/or Ship Type systems is to be provided.

3.3.5 For ships operating with two or more generator sets in service connected to the switchboard, arrangements are to be such that, in the event of loss of one generator, the remaining set(s) is to be adequate for the continuity of Mobility and/or Ship Type systems supplied from that switchboard. This may be achieved by preferential tripping of services not required for the Mobility and/or Ship Type. Alternatively, arrangements can be such that a standby generator will start automatically and connect to the switchboard on loss of one of the generator sets in service.

3.4.1 Services essential for the operation of the propulsion machinery, steering and the supply of electrical power are to be arranged so that 50 per cent of the installed prime mover capacity and not less than 50 per cent of the installed propulsion systems and steering capability are maintained in the event of a single failure in any of the services, where required by the respective class notations.

3.5.1 The arrangements for the storage of fuel oil bunkers are to ensure that there is an adequate supply of existing fuel oil on board to allow sufficient time for a shore-based quality analysis of new bunkers, in accordance with ISO 8217 Petroleum Products – Fuels (Class F) Specification of Marine Fuels prior to use.

3.5.2 Provision is to be made to enable samples of fuel oil to be taken at the bunkering manifolds.