Section 3 Operating conditions

3.1.1 The design and arrangements are to be such that the machinery can be started and controlled on board ship, without external aid, so that the operating conditions can be maintained under all circumstances.

3.1.2 Machinery is to be capable of operating at defined power ratings with a range of fuel grades specified by the engine, boiler or machinery manufacturer and agreed by the Owner/Operator.

3.1.3 Machinery is to be capable of operating satisfactorily in accordance with the manufacturer’s stated operating conditions within an operational profile specified for the ship by the Owner/Operator and agreed by the manufacturer/system designer.

3.2.1 The flash point (closed cup test) of fuel oil is to be not less than 55°C, unless specially approved.

3.2.2 Fuels with flash points lower than 55°C, but not less than 43°C, unless specially approved, may be used in ships intended for service restricted to certain geographical limits, where it can be ensured that the temperature of the machinery spaces will always be 10°C below the flash point of the fuel. In such cases, safety precautions and the arrangements for storage and pumping will be specially considered.

3.2.3 The use of fuel having a lower flash point than specified in Pt 5, Ch 1, 3.2 Fuel 3.2.1 and Pt 5, Ch 1, 3.2 Fuel 3.2.2, as applicable, may be permitted provided that such fuel is not stored in any machinery space and the arrangements for the complete installation are specially approved.

3.3.1 In the Chapters where the dimensions of any particular component are determined from shaft power, P, in kW, and revolutions per minute, R, the values to be used are to be derived from the following:

• For main propelling machinery, the maximum shaft power and corresponding revolutions per minute giving the maximum torque for which the machinery is to be classed.
• For auxiliary machinery, the maximum continuous shaft power and corresponding revolutions per minute to be used in service.

3.4.1 Main propulsion engines are defined as those which drive main propelling machinery directly or indirectly through mechanical shafting and which may also drive electrical generators to provide power for auxiliary services. Auxiliary engines are defined as those coupled to electrical generators which provide power for auxiliary services, for electrical main propulsion motors or a combination of both.

3.4.2 Units and formulae included in the Rules, are shown in SI units.

3.4.3 Pressure gauges may be calibrated in bar, where 1 bar = 0,1 N/mm².

3.5.1 The rating of main and essential auxiliary machinery is to be suitable for the temperature conditions associated with the geographical limits of the proposed service.

3.6.1 Auxiliary engines coupled to electrical generators are to be capable under service conditions of developing continuously the power to drive the generators at full rated output (kW) and of developing for a short period (15 minutes) an overload power of not less than 10 per cent, see Pt 6, Ch 2 Electrical Installations.

3.6.2 Engine builders are to satisfy the Surveyors by tests on individual engines that the above requirements, as applicable, can be complied with, due account being taken of the difference between the temperatures under test conditions and those referred to in Pt 5, Ch 1, 3.5 Temperature conditions. Alternatively, where it is not practicable to test the engine/generator set as a unit, type tests (e.g. against a brake) representing a particular size and range of engines may be accepted. With engines, any fuel stop fitted is to be set to permit the short period overload power of not less than 10 per cent above full rated output (kW) being developed.

3.7.1 Sufficient astern power is to be provided to maintain control of the ship in all normal circumstances.

3.8.1 Roller element bearings are to have an L10 design life of at least 30 000 hours, based upon the design operating conditions. An L10 design life of less than 30 000 hours would be accepted, provided it is proposed in conjunction with the manufacturer's design/maintenance manual.