CHAPTER 6 MACHINERY

101. General

Machinery installations, not specified in this chapter, are to be in accordance with the relevant re- quirements in the Rules for the Classification of Steel Ships. However, it can be accepted where the Society admit that they are satisfied with the requirements in this chapter or equivalent standard such as the Federal Aviation Regulations, etc.

102. Main propulsion and auxiliary machinery

1. General

(1) The machinery, associated piping systems and fittings relating to main machinery and auxiliary power units are to be of a design and construction adequate for the service for which they are intended and are to be so installed and protected as to reduce to a minimum any danger to persons on board, due regard being paid to moving parts, hot surfaces and other hazards.

(2) All surfaces of machinery installations with high temperature above 220 °C e.g. thermal oil and exhaust gas lines, silencers, etc and which may be impinged as a result of leakage of flamma- ble fluid, are to be effectively insulated with non-combustible material to prevent the ignition of combustible materials coming into contact with them. Where the insulation is oil absorbent or may permit the penetration of oil, the insulations are to be encased in steel sheathing or equiv- alent material.

(3) Special consideration is to be given to the reliability of single essential propulsion components.

(4) Means are to be provided whereby normal operation of propulsion machinery can be sustained,

restored or safely shut down if one of the essential auxiliaries becomes inoperative. Special con- sideration is to be given to the malfunctioning of :

(A) a generator set which serves as a main source of electrical power; and

(B) a source of essential service or supply to a main propulsion engine or main source of elec- trical power, such as fuel oil supply, pressurized lubricating oil, aspiration air, cooling water or engine starting or control systems.

(5) Means are to be provided to ensure that the machinery can be brought into operation from the dead craft condition without external aid.

(6) All parts of machinery, hydraulic, pneumatic and other systems and their associated fittings

which are under internal pressure are to be subjected to appropriate tests including a pressure test before being put into service for the first time.

(7) Provision is to be made to facilitate cleaning, inspection and maintenance of main propulsion

and auxiliary machinery including pressure vessels.

(8) The Society may accept machinery which does not show detailed compliance with the Guidance where it has been used satisfactorily in a similar application, provided that:

(A) the design, construction, testing, installation and prescribed maintenance are together adequate for its use in a marine environment; and

(B) an equivalent level of safety will be achieved.

(9) Such informations as necessary to ensure that machinery can be installed correctly regarding such factors as operating conditions and limitations are to be made available by the manufacturers.

(10) Main propulsion machinery and all auxiliary machinery essential to the propulsion and the safety of the craft are, as fitted in the craft, to be designed to operate when the craft is upright and when inclined at any angle of trim, heel, roll or pitch the craft may achieve in any normal operational mode within the range of allowable operating conditions.

(11) All pressure vessels and associated piping systems are to be of a design and construction ad- equate for the purpose intended and are to be so installed and protected as to minimize danger to persons on board. In particular, attention is to be paid to the materials used in the con- struction and the working pressures and temperatures at which the item will operate and the need to provide an adequate margin of safety over the stresses normally produced in service. Every pressure vessel and associated piping system are to be fitted with adequate means to pre- vent over-pressures in service.

(12) Arrangements are to be provided to ensure that any liquid cooling system is and alarmed (visual and audible) and means instituted to minimize the effects

rapidly detected of such failures

Guidance for WIG ships(Wing-In-Ground Effect Ships) 2012 17

on machinery serviced by the system.

2. Engine general

(1) The engines are to be fitted with adequate safety monitoring and control devices in respect of speed, temperature, pressure and other operational functions. Control of the machinery is to be arranged so that no single failure causes loss of control of machinery. The machinery in- stallation is to be suitable for operation as in an unmanned machinery space, including auto- matic fire detection system, bilge alarm system, remote machinery instrumentation and alarm system.

(2) The engines are to be protected against overspeed, loss of lubricating oil pressure, loss of cool- ing medium, high temperature, malfunction of moving parts and overload. Safety devices may provide warnings but are not to cause complete engine shutdown. Such safety devices are to be capable of being tested.

(3) At least two independent means of stopping the engines quickly from the operating compartment under any operating conditions are to be available. Duplication of the actuator fitted to the en- gine is not to be required.

(4) The major components of the engine are to have adequate strength to withstand the thermal and dynamic conditions of normal operation. The engine is not to be damaged by a limited oper- ation at a speed or at temperatures exceeding the normal values but within the range of the

protective devices.

(5) The design of the engine is to be such as to minimize the risk of fire or explosion and to en- able compliance with the fire precaution requirements.

(6) Provision is to be made to drain all excess fuel and oil to a safe position so as to avoid a fire

hazard.

(7) Provision is to be made to ensure that, whenever practical, the failure of systems driven by the engine is not to unduly affect the integrity of the major components.

(8) The ventilation arrangements in the machinery spaces are to be adequate under all envisaged

operating conditions. Where appropriate, arrangements are to ensure that enclosed engine com- partments are forcibly ventilated to the atmosphere before the engine can be started.

(9) Any engine is to be ensured that the engine is installed so as to avoid damage of structural members and machinery within the craft by an excessive vibration.

3. Gas turbines

(1) Gas turbines are to be designed to operate in the marine environment and are to be free from surge or dangerous instability throughout its operating range up to the maximum steady speed approved for use. The turbine installation is to be arranged to ensure that the turbine cannot be continuously operated within any speed range where excessive vibration, stalling, or surging may be encountered.

(2) The gas turbines are to be designed and installed such that any reasonably probable shedding of compressor or turbine blades will not endanger the craft, other machinery, occupants of the craft or any other persons.

(3) The provisions of 2 (6) are to apply to gas turbines in respect of fuel which might reach the interior of the jet pipe or exhaust system after a false start or after stopping.

(4) Turbines are to be safeguarded as far as practicable against the possibility of damage by in-

gestion of contaminants from the operating environment. Information regarding the recommended maximum concentration of contamination is to be made available. Provision is to be made for preventing the accumulation of salt deposits on the compressors and turbines and, where appro- priate, for preventing the air intake from icing.

(5) In the event of a failure of a shaft or weak link, the broken end is not to hazard the occupants of the craft, either directly or by damaging the craft or its systems. Where necessary, guards may be fitted to achieve compliance with these provisions.

(6) Each engine is to be provided with an emergency overspeed shutdown device connected, where possible, directly to each rotor shaft.

(7) Where an acoustic enclosure is fitted which completely surrounds the gas generator and the high pressure oil pipes, a fire detection and extinguishing system is to be provided for the acoustic

enclosure.

(8) The manufacturers are to demonstrate the soundness of the casings. Inter-coolers and heat ex- changers are to be hydraulically tested on each side separately.

4. Engines for main propulsion and essential auxiliaries

(1) Any main propulsion system is to have satisfactory torsional vibration and other vibrational

18 Guidance for WIG ships(Wing-In-Ground Effect Ships) 2012

characteristics verified by individual and combined torsional and other vibration analyses for the system and its components from power unit through to propulsor.

(2) All external high-pressure fuel delivery lines between the high-pressure fuel pumps and fuel noz-

zles are to be protected with a jacketed tubing system capable of containing fuel from a high pressure line failure. The jacketed tubing system is to include a means for collection of lea- kages and arrangements are to be provided for an alarm to be given of a fuel line failure.

(3) Engines of a cylinder diameter of 200 mm or a crankcase volume of 0.6 mĮ and above are to be provided with crankcase explosion relief valves of an approved type with sufficient relief area. The relief valves are to be arranged with means to ensure that discharge from them is di- rected so as to minimize the possibility of injury to personnel.

(4) The lubrication system and arrangements are to be efficient at all running speeds, due consid- eration being given to the need to maintain suction and avoid the spillage of oil in all con- ditions of list and trim and degree of motion of the craft.

(5) Arrangements are to be provided to ensure that visual and audible alarms are activated in the event of either lubricating oil pressure or lubricating oil level falling below a safe level, consid- ering the rate of circulation of oil in the engine.

(6) Where diesel engines are arranged to be started, reversed or controlled by compressed air, the

arrangement of the air compressor, air receiver and air starting system are to be such as to minimize the risk of fire or explosion.

5. Transmissions

(1) The transmission is to be of adequate strength and stiffness to enable it to withstand the most

adverse combination of the loads

for the material concerned.

(2) The design of shafting, bearings cessive vibration could not occur designed overspeed trip setting of

expected in service without exceeding acceptable stress levels

and mounts is to be such that hazardous whirling and ex- at any speed up to 105 % of the shaft speed attained at the the prime mover.

(3) The strength and fabrication of the transmission are to be such that the probability of hazardous

fatigue failure under the action of the repeated loads of variable magnitude expected in service is extremely remote throughout its operational life. Compliance is to be demonstrated by suit-

ably conducted tests, and by designing for sufficiently low stress levels, combined with the use of fatigue resistant materials and suitable detail design. Torsional vibration or oscillation likely

to cause failure may be acceptable if it occurs at transmission speeds which would not be used in normal craft operation, and it is recorded in the craft operating manual as a limitation.

(4) Where a clutch is fitted in the transmission, normal engagement of the clutch is not to cause excessive stresses in the transmission or driven items. Inadvertent operation of any clutch is not

to produce dangerously high stresses in the transmission or driven item.

(5) Provision is to be made such that a failure in any part of the transmission, or of a driven com- ponent, will not cause damage which might hazard the craft or its occupants.

(6) Where failure of lubricating fluid supply or loss of lubricating fluid pressure could lead to haz- ardous conditions, provision is to be made to enable such failure to be indicated to the operat-

ing crew in adequate time to enable them as far as practicable to take the appropriate action before the hazardous condition arises.

6. Propulsion and lift devices

(1) The provisions of this section are based on the premise that:

(A) Propulsion arrangements and lift arrangements may be provided by separate devices, or be integrated into dual-function devices.

(B) Propulsion devices are those which directly provide propulsive thrust and include machinery items having a primary function of contributing to that thrust, including any associated

ducts, vanes, and nozzles.

(C) Lift devices are those devices which generate lifting force on the craft and include arrange- ments which direct air flow from propellers or gas jets from engines to produce such force.

(2) The propulsion and lift devices are to be of adequate strength and stiffness. The design data, calculations and trials, where necessary, are to establish the ability of the device to withstand

the loads which can arise during the operations for which the craft is to be certificated, so that

the possibility of catastrophic failure is extremely remote.

(3) The design of propulsion and lift devices is to pay due regard to the effects of allowable corro- sion, electrolytic action between different metals, erosion or cavitation which may result from operation in environments in which they are subjected to spray, debris, salt, sand, icing, etc.

Guidance for WIG ships(Wing-In-Ground Effect Ships) 2012 19

(4) Design and testing of propulsion and lift devices are to pay due regard, as appropriate, to any pressure which could be developed as a result of any duct blockage, in terms of steady and cy- clic loadings, loadings due to external forces and of the use of the devices in maneuvering and reversing and to the axial location of rotating parts.

(5) Appropriate arrangements are to be made to ensure that:

(A) ingestion of debris or foreign matter is minimized; and

(B) the possibility of injury to personnel from shafting or rotating parts is minimized.

103. Auxiliaries and piping arrangement

1. General

(1) Fluid systems are to be constructed and arranged so as to assure a safe and adequate flow of

fluid at a prescribed flow rate

bility of a failure or a leakage a fire or an explosion hazard

and pressure under all conditions of craft operation. The proba-

in any one fluid system causing damage to the electrical system, are to be extremely remote. Attention is to be directed to the

avoidance of flammable liquid impingement on hot surfaces in the event of leakage or fracture of the pipe.

(2) The maximum allowable working pressure in any part of the fluid system is not to be greater

than the design pressure, having regard to the allowable stresses in the materials. Where the maximum allowable working pressure of a system component, such as a valve or a fitting, is less than that computed for the pipe or tubing, the system pressure is to be limited to the low- est of the component minimum allowable working pressures. Every system which may be ex- posed to pressures higher than the system’'s maximum allowable working pressure is to be safe- guarded by appropriate relief devices.

(3) Piping are to be pressure-tested to a pressure of the 1.5 times the design pressure. The test on any storage tank or reservoir is to take into account any possible static head in the overflow condition and the dynamic forces arising from craft motions.

(4) Materials used in piping systems are to be compatible with the fluid conveyed and selected giv-

ing due regard to the risk of fire. Non-metallic piping material may be permitted in certain sys- tems provided the integrity of the hull and watertight decks and bulkheads is maintained.

2. Arrangement of oil fuel, lubricating oil and other flammable oil

(1) Oil fuel, lubricating oil and other flammable oil lines are to be screened or otherwise suitably protected to avoid, as far as practicable, oil spray or oil leakages onto hot surfaces, into machi- nery air intakes or other sources of ignition. The number of joints in such piping systems is to be kept to a minimum. Flexible pipes carrying flammable liquids are to be of an approved type.

(2) Fuel oil, lubricating oils and other flammable oils are not to be carried forward of public spaces and crew accommodation.

(3) In a craft in which oil fuel is used, the arrangements for the storage, distribution and utilization of the oil fuel are to be such as to ensure the safety of the craft and persons on board and are at least to comply with the following provisions.

(A) As far as practicable, all parts of the oil fuel system containing oil under pressure exceed- ing 0.18 NÕmmĪ are not to be placed in a concealed position such that defects and leakage

cannot readily be observed. The machinery spaces in way of such parts of the oil fuel sys- tem are to be adequately illuminated.

(B) The ventilation of machinery spaces is to be sufficient under all normal conditions to pre-

vent accumulation of oil vapour.

(C) No oil fuel tank is to be situated where spillage or leakage therefrom can constitute a haz- ard by falling on heated surfaces.

(D) Every fuel tank is where necessary, to be provided with save-alls or gutters to catch any fuel which may leak from such tanks.

(E) Safe and efficient means of ascertaining the amount of oil fuel contained in any oil fuel

tank are to be provided.

(F) Oil-level gauges are to be of a type not to allow over-filling of the tanks that will permit release of fuel. The use of cylindrical gauge glasses is to be prohibited.

(G) Provision is to be made to prevent overpressure in any oil tank or in any part of the oil

fuel system, including the filling pipes. Any relief valves and air or overflow pipes is to discharge to a safe position and, for fuel of flashpoint less than 43°C, is to terminate with approved flame arresters.

20 Guidance for WIG ships(Wing-In-Ground Effect Ships) 2012

(H) Subject to (I), oil fuel pipes and their valves and fittings are to be of steel or other ap- proved materials, except that restricted uses of flexible pipes is to be permissible in posi- tions where the Society is satisfied that they are necessary. Such flexible pipes and end at- tachments are to be of approved fire-resisting materials of adequate strength and are to be constructed to the satisfaction of the Society.

(I) High-pressure oil fuel pipes and their valves and fittings are to be of seamless steel con- struction and are to be protected with a jacketed piping system capable of containing and collecting fuel from a high pressure line failure.

(4) The arrangements for the storage, distribution and utilization of oil used in pressure lubrication systems are to be such as to ensure the safety of the craft and persons on board. The arrange-

ments made in machinery spaces and, whenever practicable, in auxiliary machinery spaces are at least to comply with the provisions of (3) (A) and (C) to (G) except that:

(A) this does not preclude the use of sight-flow glasses in lubricating systems provided they are shown by test to have a suitable degree of fire resistance;

(B) sounding pipes may be permitted in machinery spaces if fitted with appropriate means of

closure.

(5) The arrangements for storage, distribution and utilization of other flammable oils employed un- der pressure in power transmission systems, control and activating systems and heating systems are to be such as to ensure the safety of the craft and persons on board.

(6) In addition to the provisions of 103. 2 (1) to (5), any equipment used to store or transfer flammable liquids automatically or remotely is to have arrangements to prevent overflow spillages.

3. Bilge pumping and drainage systems

(1) Arrangements are to be made for draining any watertight compartment other than the compart- ments intended for permanent storage of liquid. Where, in relation to particular compartments, drainage is not considered necessary, drainage arrangements may be omitted, but it is to be demonstrated that the safety of the craft will not be impaired.

(2) Bilge pumping arrangements are to be provided to allow every watertight compartment located below the water level in the worst anticipated damage condition other than those intended for permanent storage of liquid to be drained. The capacity or position of any such compartment is to be such that flooding thereof could not affect the safety of the craft.

(3) The bilge pumping system is to be capable of operation under all possible values of list and trim after the craft has sustained the postulated damage in Ch 5, 105. The bilge pumping sys- tem is to be so designed as to prevent water flowing from one compartment to another. The necessary valves and pumps for operation of the bilge system arranged for any compartment are to be capable of being operated from the operating compartment.

(A) At least two power pumps connected to the main bilge system are to be provided, one of

which may be driven by the propulsion machinery. If the Society is satisfied that the safety of the craft is not impaired, bilge pumping arrangements may be dispensed with in partic- ular compartments. Alternatively, the arrangement may be in accordance with the provisions of (12).

(B) On multi-hull craft each hull is to be provided with at least two power pumps, unless a bilge pump in one hull is capable of pumping bilge in the other hull. At least one pump in each hull is to be an independent power pump.

(4) The power operated self-priming bilge pumps may be used for other duties such as fire fighting or general service but not for pumping fuel or other flammable liquids.

(5) Each power bilge pump is to be capable of pumping water through the required bilge pipe at a

speed of not less than 2 m/s.

(6) The diameter (ᾘÆ ) of the bilge main is to be calculated according to the following formula, ex- cept that the actual internal diameter of the bilge main may be rounded off to the nearest size of a recognized standard:

Æ

ᾘ Ņ ĪJÑÌǾĴKNÃNÆÑÁŃŃL ǾJ

where:

ᾘÆ = the internal diameter of the bilge main (mm);

à = the length of the craft (m) as defined in Pt 1;

Guidance for WIG ships(Wing-In-Ground Effect Ships) 2012 21

Æ

Á

(7) Internal

= is for monohull craft, the breadth of the craft in m as defined in Pt 1 and for mul- ti-hull craft, the breadth of a hull at or below the design waterline (m); and

= is the moulded depth of watertight structure of the craft (m).

diameters of suction branches are not to be less than 25 mm. Suction branches are to

be fitted with effective strainers.

(8) Sea inlet valves, if any, are to be capable of being closed from the operating compartment.

(9) All bilge suction piping up to the connection to the pumps are to be independent of other piping.

(10) Any space for which bilge pumping arrangements are required is to be provided with a bilge alarm.

(11) For craft with individual bilge pumps, the total capacity Ç of the bilge pumps for each hull is not to be less than 2.4 times the capacity of the pump defined in 3 (5) and (6).

(12) In bilge pumping arrangements where a bilge main is not provided, at least one fixed sub-

mersible pump is to be provided for each space. The capacity of each pump is to be de- termined by the formula:

Çᾪ Ņ ÇÕ NC Ň ÌŃ (minimum of 8 ton/h)

where:

C = number of submersible pumps

Ç = total capacity as defined in (11).

However, where accepted by this Society, bilge discharge of small craft having max. flying weight of less than 5,670 kg may be carried out by one (1) portable bilge pump.

(13) Non-return valves are to be fitted in the following components:

(A) bilge valve distribution manifolds;

(B) bilge suction hose connections where fitted directly to the pump or to the main bilge suc- tion pipe; and

(C) direct bilge suction pipes and bilge pump connections to main bilge suction pipe.

4. Ballast systems

(1) Water ballast is not in general to be carried in tanks intended for oil fuel. In craft in which it is not practicable to avoid putting water in oil fuel tanks, oily-water separating equipment is to be fitted, or other alternative means such as discharge to shore facilities are to be provided for

disposing of the oily-water ballast. The provisions of this paragraph are without

prejudice to the

provisions of the International Convention for the Prevention of Pollution from Ships.

(2) Where a fuel transfer system is used for ballast purposes, the system is to be isolated from any water ballast system and meet the requirements for fuel systems and the International

Convention for the Prevention of Pollution from Ships.

5. The cooling arrangements provided are to be adequate to maintain all lubricating and hydraulic flu- id temperatures within manufacturers' recommended limits during all operations for which the craft is to be certificated.

6. Arrangements are to provide sufficient air to the engine and are to give adequate protection against damage due to salt, water, leaking fuel, industrial accumulation and ingress of foreign matter.

7. Machinery spaces are to be adequately ventilated so as to ensure that when machinery therein is operating at full power in all weather conditions, including heavy weather, an adequate supply of air is maintained to the spaces for the efficient operation of the machinery and safe entry by per- sonnel as necessary. Auxiliary machinery spaces are to be adequately ventilated appropriate for the purpose of those spaces. The ventilation arrangements are to be adequate to ensure that the safe operation of the craft is not put at risk.

8. Exhaust systems

(1) Exhaust systems are to be so arranged as to minimize the risk of intake of exhaust gases into manned spaces, air-conditioning systems, and engine intakes.

(2) Pipes through which exhaust gases are discharged through the hull in the vicinity of the water-

line are to be fitted with erosion/corrosion resistant shut-off flaps or other devices on the shell or pipe end and acceptable arrangements made to prevent water flooding the space or entering

22 Guidance for WIG ships(Wing-In-Ground Effect Ships) 2012

the engine exhaust manifold.

(3) Exhausts are to be arranged so that hot exhaust gases are directed away from areas to which personnel have access, either on board the craft or in the vicinity of the craft when berthed.

Guidance for WIG ships(Wing-In-Ground Effect Ships) 2012 23