Section 3 Operating conditions

3.1.1 The design and arrangement are to be such that the machinery can be started and controlled on board ship, without external aid.

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 for use in ships classed for unrestricted service is, in general, to be not less than 60°C.

3.2.2 For emergency generator engines, fuel having a flash point of not less than 43°C may be used.

3.2.3 Fuels with flash points lower than 60°C, but not less than 43°C unless specially approved, may be used in ships intended for service restricted to geographical limits where it can be ensured that the temperature of the machinery and boiler 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.

3.2.4 The use of fuel having a lower flash point than specified in Pt 5, Ch 1, 3.2 Fuel 3.2.1 to Pt 5, Ch 1, 3.2 Fuel 3.2.3 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.

3.2.5 For engines operating on `boil-off' vapours from the cargo, see Clasifications Register's (hereinafter referred to as 'LR') Rules for Ships for Liquefied Gases.

3.3.1 In the Chapters where the dimensions of any particular component are determined from shaft power, P, in kW (H, in shp), 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 which will be used in service.

3.4.1 Main propulsion engines and turbines 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 and turbines 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 followed by metric units in brackets, where appropriate.

3.4.3 Where the metric version of shaft power, i.e. (shp), appears in the Rules, 1 shp is equivalent to 75 kgf m/s or 0,735 kW.

3.4.4 Pressure gauges may be calibrated in MPa, where:

1 MPa = 10 bar = 1 N/mm² = 10,2 kgf/cm².

3.5.1 The rating for classification purposes of main and essential auxiliary machinery intended for installation in sea-going ships to be classed for unrestricted (geographical) service is to be based on a total barometric pressure of 1000 mb, an engine room ambient temperature or suction air temperature of 45°C, a relative humidity of 60 per cent and sea-water temperature or, where applicable, the temperature of the charge air coolant at the inlet of 32°C. The equipment manufacturer is not expected to provide simulated ambient reference conditions at a test bed.

3.5.2 In the case of a ship to be classed for restricted service, the rating is to be suitable for the temperature conditions associated with the geographical limits of the restricted service, see Pt 1, Ch 2 Classification Regulations.

3.6.1 Main and essential auxiliary machinery and equipment is to be capable of operating satisfactorily under the conditions shown in Table 1.3.1 Ambient operating conditions.

3.6.2 Where it is intended to allow for operation in ambient temperatures outside those shown in Table 1.3.1 Ambient operating conditions, the permissible temperatures and associated periods of time are to be specified and details are to be submitted for consideration. Propelling and essential auxiliary machinery, see Pt 1, Ch 2, 2.8 Descriptive notes 2.8.1, is to retain a continuous level of functional capability under these conditions and any level of degraded performance is to be defined. Operation under these circumstances is not to be the cause of damage to equipment in the system and is additionally to be acceptable to the National Authority of the country in which the ship is to be registered.

3.7.1 Main and essential auxiliary machinery is to operate satisfactorily under the conditions as shown in Table 1.3.2 Inclination of ship.

3.7.2 Any proposal to deviate from the angles given in Table 1.3.2 Inclination of ship will be specially considered taking into account the type, size and service conditions of the ship.

3.7.3 The dynamic angles of inclination in Table 1.3.2 Inclination of ship may be exceeded in certain circumstances dependent upon ship type and operation. The Shipbuilder is, therefore, to ensure that the machinery is capable of operating under these angles of inclination.

3.8.1 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 in the case of reciprocating internal combustion engines and gas turbines, of developing for a short period (15 minutes) an overload power of not less than 110 per cent of full rated output, see Pt 5, Ch 2, 9.2 Air receiver capacity. In the case of reciprocating internal combustion engines, they are to be tested at works trials as required by Table 2.11.1 Scope of works trials for engines in Pt 5, Ch 2 Reciprocating Internal Combustion Engines.

3.8.2 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 Ambient reference 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 and gas turbines 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.

3.9.1 In order to maintain sufficient manoeuvrability and secure control of the ship in all normal circumstances, the main propulsion machinery is to be capable of reversing the direction of thrust so as to bring the ship to rest from the maximum service speed. The main propulsion machinery is to be capable of maintaining in free route astern at least 70 per cent of the ahead revolutions corresponding to the maximum continuous ahead power for which the vessel is classed.

3.9.2 Where steam turbines are used for main propulsion, they are to be capable of maintaining in free route astern at least 70 per cent of the ahead revolutions corresponding to the maximum continuous ahead power for which the vessel is classed for a period of at least 15 minutes.

3.10.1 Interlocks are to be provided to prevent any operation of engines or turbines under conditions that could cause a hazard to the machinery and personnel. These are to include ‘turning gear engaged’, ‘low lubricating oil pressure’, where oil pressure is essential for the prevention of damage during start up, ‘shaft brake engaged’ and where machinery is not available due to maintenance or repairs. The interlock system is to be arranged to be ‘fail safe’.

3.10.2 Where machinery is provided with manual turning gear, warning devices or notices may be provided as an alternative to interlocks as required by Pt 5, Ch 1, 3.10 Machinery interlocks 3.10.1.