class 4 eoow

7/31/2019 class 4 eoow

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1. What Steering Gear Checks would you do before Setting Sail?

Prior to a Ship's departure from any Port, the Steering Gear should be tested to ensure satisfactory Operation.These Tests should include:

Operation of the Main Steering GearOperation of the Auxiliary Steering Gear or the use of the Second Pump which acts as the Auxiliary.

Operation of the Remote Control Systems from the Main Bridge Steering Positions.Operation of Steering Gear using the Emergency Power Supply.

The Rudder Angle Indicator Reading with respect to the actual Rudder Angle should be checked.The Alarms fitted to the Remote Control System and Steering Gear Power Units should be checked for Correct

Operation.Steering Gear Header Tank Level should be checked.

2. What checks should be carried out on a Breathing Apparatus Set before entering a smoke filled

compartment?

The following checks should be carried out:Ensure the bottle is full,Check operation of low pressure whistle, andFace seal check should be carried out.

3. How would you check that there was excess water in the Sump?

By using Water Finding Paste.4. What is the purpose of the Over Current Protection Trip?

The purpose of the Over Current Protection is to Trip the Generator in Overload situations. The Trip is usually

set at 150% Operating Capacity and has a time delay of usually 20 seconds. This allows for short periods of

Overload Currents. It also protects against a Short Circuit in the Generator.

5. Fresh Water supplied for Drinking and Culinary purposes must meet Specified Purity Standards. How

is this achieved?

These Standards are met by passing the Fresh Water through a Hypochlorinator where the Water is Sterilised by

an excess dose of Chlorine provided as Hypochloride Tablets. It is then de-chlorinated in a Bed of ActivatedCarbon to remove excess Chlorine. Any Colour, Taste and Odour, which was present in the Water, will also beremoved by the Carbon.Another Method is to pass the Fresh Water through an Ultra Violet Steriliser.


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6. Howdo you

purify

HFO?

Heavy Fuel Oil is purified using a Centrifugal Separator, which operates by the principle of Centrifugal Force

separating two liquids, in this case Fuel Oil and Water by means of a Cylindrical Interface between the two. The

positioning of this Interface being very important for the correct operation.

7. Why is Simultaneous Injection of Fuel Oil and Starting Air into a Main Engine Cylinder Undesirable and How isit Prevented

Simultaneous Injection of Fuel and Starting Air into a Cylinder is Undesirable as it could lead to an Explosion inthe Start Air System.

It is prevented by means of Interlock, which prevents Fuel being injected when the Air Start Auto Valve isOpen.

The Interlock Operates a Stop Solenoid, which keeps the Fuel Rack at Zero Position.


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8. What are the requirements of a Fixed CO2 Fire Fighting Installation?

The System must give 40% saturation of the Compartment to be filled.85% of the CO2 charge must be discharged into the Compartment within the first two minutes.

9. State the problem caused by electrical current being induced into shafting of rotating machinery.

A problem that can arise from currents generated in the rotor shaft due to stray magnetic fields, under faultconditions these stray fields can be very large, these currents if allowed to flow, would arc across the bearingsurface and cause small craters which would eventually destroy the bearings.

10. What oxygen levels would you regard as safe to enter an enclosed space?21%

11. What type of Safety Valve is fitted to a Boiler and at what Pressure does it Lift?The type of Safety Valves fitted to Boilers are High Lift Safety Valves and are designed to Operate at 10%Boiler working pressure and must also be capable of releasing all the Steam the Boiler can produce withoutthe pressure rising more than 10% over a set period: 15 min for Tank Boilers and 7 mins for Water Tube.

The spring pressure, once set, is fixed and sealed by a Surveyor.

Note: The above Test is known as the Accumulation of Pressure Test.


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12. How is a Medium Speed Engine Reversed (without CPP)?In Medium Speed Diesel Engines, reversing is achieved by the use of Duplicate Cams for the Air InletValves, Exhaust Valves and Fuel Pumps. Air Start Distributor Timing is also changed by means of

Camshaft Movement or by a Directional Air Supply being admitted to the Start Air Distribution, toreposition Cams.To engage correct Cams for Ahead and Astern Movements, the Camshaft slides axially in its Bearings. Thismovement is controlled by the Camshaft Reversing Gear, which is normally a Servo Piston. Motion of the

Piston being directly transmitted to the Camshaft.

Note: In a Slow Speed, only Duplicate Fuel Cams required.

13. What is the procedure for entering an enclosed space?

An enclosed space entry permit is required which can only be obtained with the permission of a responsibleofficer. This permit will list the conditions to be met before entry.

The space should be well ventilated before entry takes place; Before entry, oxygen levels must be checkedusing an O2 Meter.

Another person should remain at the entrance while the person is in the space, to summon assistance ifnecessary and there should also be means of communications arranged between the person within the space

and the attendant.


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Lifelines and harnesses should be available at the entrance to the space.

If the occupant appears to be in danger, the attendant should first raise the alarm, but should not enter thespace unless equipped with breathing apparatus

14. What is Single Phasing of a Motor?

Single Phasing is where one of the 3-phase's supplying the Motor becomes disconnected. The Motor willcontinue to run if this happens and can result in Motor Burnout. The effect of Single Phasing is to increase

the Current in the two remaining Lines and cause the Motor to become very noisy due to uneven Torqueproduced.

15. Describe an Inert Gas GeneratorThe Inert Gas Generator burns fuel in designed quantities to produce perfect combustion. This produces an

exhaust gas, which is largely nitrogen and carbon dioxide with a very small oxygen content. The exhaustgases pass to a cooling and washing chamber to remove sulphur and excess carbon. The washed or scrubbedgas is now inert and passes to a distribution system for Fire Fighting. The complete unit is arranged to beindependently operated in order to supply inert gas for as long as the fuel supply lasts.

On tankers the inert gas can be supplied and used to blanket the oil cargo during discharging operations.Empty tanks are filled with gas and inert gas is blown out when oil is loaded.


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16. What is the Maximum Compressed Air Temperature that should leave an Air Compressor?93C

17. What is the First Indication of a Leaking Exhaust Valve?The First Indication of a Leaking Exhaust Valve is a rise of Exhaust Gas Temperature at the outlet of the

Valve.

18. Where would you expect to find a CO2 Extinguisher?Machinery spaces, particularly near electrical equipment, such as switchboards.

19. How much foam is produced from a 9L Foam Extinguisher?

72 litres of Foam.


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20. What must the capability of Gravity Davits be with regards heel of ship?

The Davits must be able to lower the Lifeboats when the Ship is heeled to 15 degrees on either side.

21. What are the safety precautions to be observed prior to and during crankshaft deflections?Safety precautions to be observed when taking crankshaft deflections are;

Ensure the starting system is shut down and isolated, with do not start signs placed.Ensure lubrication system is isolated, plus priming system.

Before using the turning gear, check with the bridge that it is clear to so if engine is direct drive ( ie noclutch ).

Check indicator cocks are open to prevent undue load on the turning gear.Before turning the engine, ensure that there are no personnel in the crankcase and there are no obstructions.

22. What is done to ensure that a Lifeboat Engine will start when needed?

At least once every two weeks, but better still once a week the Lifeboat Engine should be run, all Fuel andOil Levels checked and the gearbox should be operated i.e. Engine run astern and ahead to check Operation.Most Engines are air cooled, but some are a combination of air and water, in which case water level checked

and if operating in cold climates anti-freeze levels also.

Larger Lifeboat Engines will be battery started, therefore condition of battery must be checked i.e. S G ofelectrolyte and that electrolyte is covering cell plates.

23 How can Exhaust Valve Leakage be confirmed?

Exhaust Valve Leakage can be confirmed by taking an Indicator Card, the Card should be taken with Fuel"On" and "Off" the Unit. If the Valve is leaking, the compression pressure and maximum pressure will below

24 How is a liner gauged?

A cylinder liner is gauged using a ball ended micrometer , the micrometer should be checked for accuracy byfirst checking it using a set datum, normally supplied with the engine when built for this purpose. Amanufacturers measuring gauge with set positions on it vertically is used in conjunction with the insidemicrometer. ( see sketch )

Before readings are taken, the temperature inside the liner is taken.The readings are then taken in the port to stbd directions and in fore an d aft directions.To get an accurate reading, the manufacturers gauge is placed in the liner in one of the above positions, thena chalk mark is made in the holes where the micrometer is placed, the gauge is then placed on the opposite

side, and the readings are taken using the chalk mark as a reference point.The " rocking" method is then used to get an accurate reading with the micrometer, ie the micrometer is

moved up and down, side to side, until the micrometer is just touching the opposite side from the gauge, thechalk mark aiding this procedure.

25 What is the Function of an Evaporator in a Refrigeration System?The Function of the Evaporator is to boil off the liquid Refrigerant, at the same time cooling the air. The

design of the System and Evaporator should be such that all Liquid Refrigerant is boiled off and the gasslightly superheated before returning to the Compressor.


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26 What Fittings would you expect to find on a Start Air Receiver?

Fittings found on a Receiver are: Safety Valve, Fusible Plug, Isolating Valve to Main Air Start System, FillingValve from Compressor, Drain Valve, Valve to Control Air, Valve to Whistle, Pressure Gauge.

27 What is "Water Hammer" and its danger?

When steam lines are shut down it is possible from various causes for them to fill with water. If steam is allowed toenter a line with water, the steam starts to move the water down the line. The steam in contact with the water

eventually condenses and a vacuum is formed causing the water to be pulled back to the valve which has just beenopened and striking it with a heavy blow, often fracturing the valve. If the valve fractures, it may end disastrously

with risk of loss of life.

28. What advantage do Inert Gas producing units used for Fire Fighting Installations have over CO2 and Halon

Systems?


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Inert Gas Producing Units have the advantage of being able to continuously produce Inert Gas. A bottle storage

system, such as CO2 or Halon Flooding is a "one shot" Fire Extinguisher which leaves a ship unprotected untilfurther gas supplies can be found.

29 Is the Code of Safe Working Practises Law?

Yes it is Law.

30 How is a Liferaft Launched?

A Liferaft is simply launched by releasing it from its lashings, a painter is secured to the Ship and the Liferaftcontainer is thrown over the side. Inflation takes place automatically, the container bursting open and the Liferaftfloats clear. A pressurised cylinder of CO2 is used to inflate the raft. Liferafts must normally be boarded fromwater level, dry if possible.

31 Where On Board a Ship would you find Information on the Carriage of Hazardous Substances?

Information on the Carriage of Hazardous Substances would be found in the IMDG (International Maritime

Dangerous Goods Code), which would normally be found on the Bridge.

32 Why are High and Low Suctions fitted on Fuel Oil Service Tanks?

The High and Low Suctions are a Safety Feature to prevent invertent Shut Down of Main Engines, Generators andBoilers due to Water Contamination of the Fuel. Normally the Low Suction is kept in use. If any Water shouldfind its way into the Fuel and Service Tank, it will gradually separate towards the Tank Bottom. When it becomes

apparent Water is present by finding it at the Tank Drains or by Operation of the Engine, it is possible to bring theHigh Suction into Operation and avoid Shut Down.

33 How does a Foam Nozzle work?

The foam nozzle works on the Venturi Principle where air is drawn into the nozzle aerating the foam solution for

good quality fire fighting foam.

34 Give a Shipboard use of Spheroidal Cast Iron and the Properties that make it suitable for this use.

Cylinder Heads and Liners.It has high compressive strength qualities and also good wear resistive qualities.

35 Why do you require Earth Lamps on 220V Distribution Board when you have them on the Main Switchboard?You require Earth Lamps on the 220V Distribution Board as well as the Main Board, due to the air gap in stepdown transformer, i.e. 440V Earth Lamps can not detect Earth on 220V systems due to the gap.

36 What should be used with Breathing Apparatus Sets when entering a Space or Compartment?A time in/time out board should be used. This board will normally have a built in clock. On this board the time thewearer enters a space is noted, plus bottle number and pressure, the time the wearer is due out is calculated as the

time the low-pressure whistle operates at. This gives the wearer time to exit.37Where would you expect to find a Foam Extinguisher?It would be located in the Engine Room, in the vicinity of Flammable Liquids, also Bunker Stations.

38 What is regarded as an enclosed space?


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An enclosed space is a space that cannot be assumed to contain oxygen.These are spaces such as a duct keel, a double bottom tank, a cofferdam, boiler, etc.

39 Would you enter an enclosed space if the oxygen levels were recorded as 19% or below?

No

40 Explain Heavy Oil Fuel System from Bunker Tanks to Engine.

Fuel is pumped from the Fuel Oil Double Bottoms via a Transfer Pump to a Fuel Oil Settling Tank where it isheated. The Fuel Oil Purifiers/Centrifuges take suction from the Settling Tank via Purifier Heaters, pass throughthe Purifiers, where any water and impurities are removed and passed on to the Service Tank which also has a set ofHeating Coils.

From the Service Tank the Fuel then passes via a Flow meter to the Mixing Tank, from where the Booster Pumpstake suction, discharging to the Fuel Oil Heaters, where the correct Fuel Oil Temperature/Viscosity is achieved forcorrect Fuel Combustion in the Engine. The Fuel then passes through the Viscosity Regulator which controls theHeater Temperature, then on to the Fuel Oil Filters (which are heated), to the Fuel Pumps, then to the Fuel Injectors

via Double Skin/Wall High Pressure Pipe.

Any surplus Fuel returns via a Regulating Valve from the Fuel Pumps back to the Mixing Tank.Diesel Oil can also be used in the System and is fed to the System via a three-way valve.

Note: When Diesel is used, no heating is required.

41 What are you looking for when you pull a Piston?


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When you Pull a Piston, you are looking for any damage to the Piston Crown, including cracks.

The Condition of Piston Rings are checked, plus Piston Ring Grooves.Check for any scuffing of Piston Skirt

Check condition of Top End Bearing Bush and Gudgeon Pin, plus clearance between Pin and Bush.Check Lubrication Bores are clear on under side of Piston.

42 What is meant by the Term, Type Ex'd'?

Ex'd' = Flame Proof Enclosure.This is an enclosure that will withstand an Internal Explosion of Flammable Gas within itself and dissipate heatfrom that explosion before reaching outside atmosphere, which could ignite the gas in surrounding atmosphere, i.e.

a Ship's Battery Locker could be classed as Ex'd'.

43 What are the two main functions of a cable gland?

The two main functions of a cable gland are, to prevent ingress of water and to hold the cable securely in position.

44 What is the difference between Cylinder Lub Oil of Trunk Piston Engines and Crosshead Engines?The Cylinder Lub Oil used in Trunk Piston Engines is the same as the Main Engine Oil, usually in Trunk PistonEngines, the quality of Fuel used is better than that of Crosshead. Therefore the TBN (Alkali content of the Oil) is

lower.Cylinder Lub Oil used in Crossheads have a high TBN, as the Fuels used are of cheaper quality and a high amount

of acidic properties are formed from combustion, hence needing a higher TBN content to neutralize these acids toprevent corrosion.

45 What different types of Fire Fighting Foam are there?

AFFF - synthetic typeProtein based Foams (Ox's blood)Which can be low expansion for use on decks etc for fire-fighting, orHigh expansion, which can be used in Machinery Spaces.

46 How are HFO Impurities Removed?

Impurities in Heavy Fuel Oils are removed by centrifugal separators i.e. purifiers and clarifiers. Liquids andSludges being removed by Purifiers, Solids by Clarifiers.

47 What are the Marpol Restricted Areas?

The Marpol Restricted Areas are: The Mediterranean Sea, Baltic Sea, Black Sea, Red Sea, "Gulf Areas", North

Sea, Antarctic, wider Caribbean Region including Gulf of Mexico and the Caribbean Sea.

48 What is an indication in the Exhaust Gas of Good Combustion?

Grey Smoke indicates Good Combustion.49 Give an example of Densities of Oils and Gravity Disc Sizes Used.

Heavy Fuel Oil: 950kg/m3

Lub Oil: 870kg/m3Diesel Oil: 880kg/m3

50 What is the Primary Function of the Expansion Valve in a Refrigeration System?


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The Primary Function of an Expansion Valve in a Refrigeration System is to regulate the Flow of Refrigerant fromthe H P side to the L P side of the System. The pressure drop causing the Saturation Temperature to drop, enabling

it to boil off at the Low Temperature of the Evaporator.

51 What is fitted in a Foam or Water Type Fire Extinguisher that ensures liquid, not gas comes out on discharge.

A diptube or internal pipe is fitted in the Fire Extinguisher, which is connected to the extinguisher hose and travelsto the bottom of the extinguisher.

52How do you take sterntube bearing weardown ?


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This is taken in drydock, on the outboard side of the sterntube is a plug that can be removed to allow for access to

check the weardown by means of depth gauge, the reading taken will be compared to readings from new.

53 What is meant by the Term, Type Ex'i'?

Ex'i' = Intrinsically Safe.Equipment with circuits that do not generate enough heat to ignite a gas. This generally means limiting circuits to

less than 30V, 50mA.

54 What are the two Main Types of Battery commonly used on board Ships?

Lead Acid and Alkaline.

55 What does a Positive Displacement Pump require that a Centrifugal Pump does not?

A Relief valve.

56 What are the rough Lub Oil Pressures on the following, on a 2 stroke Engine: Piston Cooling; CrossheadBearings and Main Bearings?

Piston Cooling: 6-7 barCrosshead Bearing: 4-5 bar

Main Bearing: 2.5-3 bar.

57 What is the Normal Reading on and Insulation Test Meter?

Infinity 00 is a normal reading, but readings should be kept above 5MW.

58 Why are Quick Closing Valves fitted in a Fuel System and how can they fail to operate?

Quick Closing Valves are fitted in Fuel Systems so that in the event of a Fire in the vicinity of these Systems or a

Fracture or Break in these Lines, the System can be shut down rapidly and remotely.They may fail to operate if not maintained or tested regularly.

59 How can the bottom end bearing clearance be checked?

The bottom end clearance can be checked by using a set of feelers to get the clearance between the bottom end

shells and the crank pin.Another method is to measure the inside diameter of the bearing shells and the outside diameter of the crank pin and

difference between the two, will be your clearance.

60 What Safety Devices are Fitted to a Start Air Line?

Non Return Valve, Flame Traps/Arrestors, Bursting Discs and Safety Valves.

61 What would cause Excessive Exhaust Temperatures?

On a Single Cylinder, it could be an Incorrect Fuel Pump Timing i.e. late Injection causing after-burn, too much

Fuel, leaking Fuel Injector or burnt out Exhaust Valve. If all Exhaust Temperatures were High, it could be due to


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High Scavenge Temperature, Charge Air Cooler Fouled, Turbo Charger Air Filters Dirty or Fouled, High Engine

Load.62 Describe a Self-Contained Breathing Apparatus Set.

The Self-contained Breathing Apparatus Set usually consists of one or two cylinders of compressed air kept in aharness, which is carried on the back. Cylinders usually being charged to a pressure of around 200-240 bar. The

high pressure air is fed through a reducing valve and then to a demand valve, which can be set in positive pressuremode, that will supply a constant demand of air, or in demand mode, which will only supply air as the wearer

demands. A non-return valve permits breathing out to atmosphere.The set incorporates a warning whistle that sounds on low air pressure.A standard cylinder will allow for about 20-25 minutes operation, but this will also depend on a few factors, such asworkload of wearer.

63 What is the Principle Operation of a Heat Detector?

This type of Heat Detector uses two bi-metalic strips/coils attached to a vertical support bracket. Whentemperature is present, the bi-metalic strips will start to move, at a fixed temperature the first strip will hit a stop,the second strip continuing to move, thus the contact is made and triggers the alarm.

64 What is the purpose of the two sets of relief valves on a Bulk CO2 System.

The purpose of the two sets of relief valves on a Bulk CO2 System is that one set being an L P Set being set at 24.5

bar and designed to relieve excess pressure to atmosphere in the event of over pressure.The H P Set is at 27 bar and is required to discharge into the Compartment, i.e. in the event of a Fire in the BulkCO2 Compartment, this causes a rapid rise in pressure and in theory CO2 will discharge into the compartment,extinguishing the fire.

65 What would you do in the Case of a Crankcase Explosion?

When the Alarm sounds, the Engine Speed must be reduced to slow and permission obtained to stop the Engine.Inform Chief Engineer.

When an Engine has stopped under Alarm Conditions under no circumstances must any doors or inspectionwindows be opened.

Oil should continue to be circulated and time allowed for the Hot Spot to cool.The early opening of doors could cause an explosion due to ingress of air.During Cooling down Period, the Engine Room Staff must keep clear of the side of the Engine fitted withExplosion Doors.

After a period of at least 20 minutes, stop the Lubricating Oil Pump, cut off all Air and engage Turning Gear.The Access Doors should then be opened and Personnel must keep clear of possible flames. Under no

circumstances should naked lights be used nor should anyone be permitted to smoke.Examination should then take place for any squeezed out bearing metal or loose bearing metal in the Crankcase.

Heat discoloured Metal Parts or blistering of Paintwork must be investigated. The Ceiling of the Crankcase andGuide Bars should also be observed. If the Crankcase is clear, the Camshaft Drive and Main Thrust Bearing should

be inspected for signs of overheating.Should any damage be found, then a permanent repair must be put in hand immediately.After repair, Lub Oil should be checked for Free Flow.The Engine should then be run in i.e. 15 mins, then check components for signs of overheating, then half an hour at

half speed, again check, then one hour full speed, then check again.Note: Varying times have been quoted for the Cooling Down Period and no set rules are available, but, the longerthe time taken, the greater the Safety Factor.

66 Why and what type of Valves are Boiler Feed Check Valves?


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The Feed Checks are Non-Return type Valves and are fitted in pairs, one being the Main, the other, the Standby or

Auxiliary and they must give an indication of Open or Closed Positions. They are of Non-Return type to preventBack Flow of Boiler Pressure down the Feed Line.

67 What is Sequential Starting?

Sequential Starting is the automatic starting of essential equipment when power is returned after a total power

failure, i.e. equipment such as Steering Gear.

68 How does a Turbo-charger work?

The Turbo-charger mainly consists of a Turbine and a Compressor assembled as a single unit on a Shaft.The exhaust gas from the Engine flows through a water-cooled gas inlet (cooling from Engine Jacket Water

System) to a nozzle ring, which directs gases at the Turbine Rotor Blading. This force causes the Rotor to rotate atHigh Velocity. The gases leaving via a water-cooled gas outlet casing, to an exhaust pipe and to atmosphere.The air required for the Diesel Engine is drawn in by the Compressor via a combined Silencer/Filter. The entry

passage after the filter is then divided into splitters which prevent draught losses and guide the air to the

compressor, the air being drawn in axially by the compressor and discharged radially at high velocity to the

diffuser, which changes much of the velocity to pressure. From the diffuser the air passes into the Volute Casing,changing the rest of the airs Kinetic Energy to pressure before being discharged to the Charge Air Cooler and to theEngine for Combustion.

69 What happens to the CO2 System in Drydock?

What happens to the CO2 System in Drydock?

70 Describe how Synchronising Lamps are used to Parallel a Generator.

This is normally used as a back-up or alternative way to the Synchroscope, the Lamps are connected between theIncoming Generator and the Bus-bars. The "Sequence Method" is the preferred one as it displays a rotation of

Lamp Brightness, which indicates, whether the incoming machine is running fast (clockwise) or slow (anticlockwise). As with the Synchroscope, the Lamp Sequence must appear to rotate slowly clockwise. Correct

synchronisation occurs when the top or "Key" lamp is dark and the two bottom lamps are equally bright.


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71 State the regulations regarding the Emergency Fire Pump.The Emergency Fire Pump is to be located remote from the Machinery Space and with Independent Means ofPower, which could be a diesel engine or from the Emergency Switchboard.

72 What would cause the Level of the Lub Oil Sump or Drain Tank to Rise?

Water entering the oil, or fuel or even a Lub Oil Filling Valve passing.

73 How many pumps are there in the Engine Room that you can pump Bilges with?

A Bilge Pump which is normally Positive Displacement.


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The others may vary from Ship to Ship, but can be the Ballast Pump, General Service Pump and Main Sea Water

Cooling Pump. These Pumps are only used for Pumping Bilges in the event of an emergency and have anEmergency Bilge Suction/Injection Valve connected to them.

74 How can currents of this type be avoided or reduced?

Currents of this sort may be avoided in machines by insulating one or both bearings, the insulation may be at the

bearing housing or more commonly , beneath the pedastal where it seats on the bedplate stool, the insulation of onebearing is more usual, but insulating both allows insulation to be checked, where both are insulated, an earth strap isfitted. Also holding down bolts are insulated.

75 What is Uniflow Scavenging?

With Uniflow Scavenging, the Incoming Air enters at the Lower End of the Cylinder and Leaves at the Top. TheOutlet at the Top of the Cylinder being a Large Exhaust Valve. The advantage of Uniflow is the simple design of

the Liner, plus it is the most efficient.


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76 On what type of Fires would you use a Foam Extinguisher?

Class B Fires: Fires burning liquids such as lubricating oil and fuels.

77 What is the Function of a Fuse?

The function of a Fuse is to give Short-circuit Protection and also Overload Protection and operates in milliseconds78 What Interlocks are there on the Start Air System?An Interlock to prevent Fuel being Injected

An Interlock on Turning Gear and

An Interlock CPP System, pitch has to be on Zero before Starting Engine.


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78 What type of Pumps are used for Pumping Bilges in an Emergency?

These Pumps are normally High Capacity Centrifugal Pumps.

79 What are the Causes of Single Phasing?

Single Phasing can be caused when one of the three back up fuses blows or if one of the contactor contacts is inopen circuit.

80 Where on the ship is the Emergency Generator Located?


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The Emergency Generator is located remotely from the Engine Room, usually on the Accommodation Deck or at

Weather Deck Level or above.

81 What action would you take if you spotted oil in the Gauge Glass of a Boiler?

The action to be taken would be to scum the boiler and blow down the gauge glass. Then the source ofcontamination investigated and stopped.If the oil contamination is excessive, then alternative heating source must be found for engine fuel, if running onheavy or change over onto diesel.

The boiler should then be shut down, allowed to cool and vent.The top door of the drum should then be removed and the oil overflowed from the drum.Ideally the boiler should be degreased before re-using.Source of contamination must be found and remedied.

82 What are the Symptoms of a Scavenge Fire?

When a Scavenge Fire has broken out, the Scavenge Air Temperature and the Exhaust Temperature of the Unit in

question will increase considerably and in some cases the Turbocharger may start Surging. Even Hot Spots on the

Scavenge Trunking can be found.

83 What would you do in the event of a Scavenge Fire?

If a Scavenge Fire were to start, the two main objectives are to confine the Scavenge Fire to the Scavenge Spaceand to minimise damage to the Engine.In the event of the Fire breaking out, inform Bridge that the Engine is to be brought to Dead Slow Ahead and also

inform the Chief Engineer.The Fuel should be cut off to that particular Cylinder. The Cylinder Lub Oil should be increased to prevent seizureand wear.If Fixed Fire Fighting Equipment is attached to the Scavenge Trunking, this can be brought into operation,

depending on severity of situation. But in most cases the Fire will generally subside within 5-15 minutes.Once the Fire is out and Navigational Circumstances allow it, the Engine must be Stopped.

Do not open Scavenge Space Doors or Crankcase Doors before Site of Fire has cooled down. When opening up,care must be taken to keep clear of any flame.

After opening up, all scavenge spaces must be thoroughly cleaned and all debris removed. The Piston Rods andCylinder Liner should be examined for surface blemishes, straightness, etc., and the Diaphragm Glands (StuffingBox) examined to ensure that they are operational and not damaged.Also Piston Rings should be checked, as Blow By may have been the Ignition Source of the Fire. If possible the

Piston Head in question should be renewed at the earliest possible moment and the damaged Unit overhauled.On Engines fitted with Tie Bolts, it may be necessary to re-tighten the Bolts adjacent to the Fire.

When starting the Engine again, care must be taken after switching on the Fuel to the Cylinder in question, and thatalso the Cylinder Lub Oil quantities are reduced to normal.

84 What would happen if the Lub Oil Pressure just dropped to Zero?The Engine would Shut Down on the Low Lub Oil Pressure Trip.

85 Draw and explain how Earth Lamps works.

A direct earth on one pole will short circuit it's lamp, causing the other two to shine brightly.


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85 What is the Purpose of the Scum Valve on a Boiler?

The Scum Valve on a Boiler is connected to a shallow dish positioned at the normal water level of the Boiler andenables the Blowing Down or Removal of Scum and Impurities from the Water Surface.

86 What are the most common faults that mechanicl / hydraulic governors are prone to?

The most common fault and relates to 50% of them is due to oil condition or the wrong type of oil being used.Other faults are worn or broken springs, or worn governor drives.

The engine hunting due to air in the governor hydraulic oil system.

87 What is a good practice before using a Dry Powder Extinguisher?It is good practice to give a Dry Powder Extinguisher a shake before use, as the Extinguisher could have been lying

for a while causing the powder to clog up.


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88 How would you Blow Down a Boiler Gauge Glass?

Close the Water and Steam Cocks on the Gauge Glass and open the Drain.Then open the Steam Cock - a strong jet of Steam should be seen from the Drain.

Close the Steam Cock.Open the Water Cock - a strong jet of Water should be observed from the Drain.

Close the Water Cock and then close the Drain.Then open the Water Cock, the water will rise in the Gauge, above normal level.

Then open the Steam Cock, the Water should then settle down, finding its correct level.

89 How are accurate reading ensured while taking crankshaft deflections?

Accurate readings are ensured by checking the condition of load of the ship, i.e crankshaft deflections are best takenwhen the ship is unloaded.

The crankcase temperature is taken into consideration.Competent personnel take the readingsWhere the readings are taken near the turning gear end of the crankshaft, on larger engine, consideration may haveto be taken for these readings as there may be slight lift in the crankshaft from the turning gear.

90 What are Batteries used for On-Board Ships?

They are used for supplying essential power to: Radio Equipment, Telephone Exchange, Fire Detection, GeneralAlarm Circuits, etc. These Systems are often supplied from two sets of batteries worked on a regularcharge/discharge cycle.They are also used as Emergency Supplies, i.e. for Emergency Generator Start-up and Emergency Lighting. Being

used in this case in a "stand-by" role to give power when Main Supplies fail.

91 Fires are classified according to the types of material, which are acting as the source, what are theseClassifications?

Class A - Fires burning wood, glass fibre, upholstery and furnishingsClass B - Fires burning liquids such as lubricating oil and fuels

Class C - Fires burning gas fuels such as liquefied petroleumClass D - Fires burning combustible metals such as magnesium and aluminiumClass E - Fires burning any of the above materials together with high voltage electricity.

92 What percentage of Engine Speed does the Overspeed Operate at?

10-15% maximum Speed.

93Explain and sketch a Funnel Inert Gas System.In a Boiler Funnel Inert Gas System, exhaust gas is taken from the Boiler Uptakes and passed through a scrubbertower where the gas is cleaned with sulphur and excess carbon being removed.

The Gas which by then is considered inert and mainly contains Nitrogen and Carbon Dioxide with less than 5%Oxygen, is then supplied via blowers and deck seal which acts as a non-return valve, along deck pipes to cargo

banks.The inert gas being used to blanket the oil cargo during discharging operations. Empty tanks are filled with gas and

the inert gas is blown out when oil is loaded.


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94 Why is a Jacket Water Safety Valve fitted on Air Compressors?

It is fitted to relieve excess pressure in the Cooling System should a Cooler Tube burst and Compressed Air escape.

95 What Conditions are Necessary to Parallel two Generators?

The Speed of both Machines must be the Same i.e. the Frequency and the Voltages must be the Same and in Phase.

96 The Main Engine Cylinder Lubricating Oil Tank is empty, oil drums are on the Main Deck beside run downPipes to the Tank and air is handy - What do you do?

If need be, the engine should be stopped to allow filling of the tank. Under no circumstances should you use the airhose to pressurise the drums to speed up the process. Oil drums are not a pressure vessel and it could lead to a

fatality.

97 Where would you expect to find a Dry Powder Extinguisher?

It is usually located near Electrical Equipment in the Machinery Space and elsewhere on the Ship.

98 What action would you take in the event of Fire breaking out in the Machinery Space?

If a Fire breaks out, the alarm should be raised and the Bridge informed immediately. If the Ship is in Port, theLocal Fire Authority should be called. If possible, an attempt should be made to extinguish or limit the fire by any

means possible (a Fire in its first few minutes can usually be readily extinguished).Ventilation fans should be stopped (should stop automatically on activation of fire alarm). Openings to the spaceshould be sealed to reduce the supply of air to the fire and to prevent it spreading. Any fuel lines feeding the fire orthreatened by it should be isolated. If practicable, combustible materials adjacent to the Fire should be removed.


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After the Fire has been extinguished, precautions should be taken against spontaneous re-ignition.

Personnel, unless wearing breathing apparatus, should not re-enter a space in which a fire has occurred before it hasbeen fully ventilated.

99 With regards Dry Powder Extinguishers, what testing and maintenance should be carried out?

Being a pressure vessel, the container is tested to 35 bar every four years.Operating mechanism checked, where practical every three months.

100 What is the range of a Foam Fire Extinguisher?

The range of a Foam Fire Extinguisher is roughly 7m.

101 What is the purpose of Rocker Gear on an Engine?

The purpose of the Rocker Gear is to operate the Inlet and Exhaust Valves on the Cylinder Head.

102 Explain what would happen if you were to lose a Generator.

First the Standby Generator set would start up and automatically put itself on the Board. If this did not happen, the

Ship would "Black Out" and after a time delay, usually 30 seconds, the Emergency Generator would start up andsupply the Emergency Switchboard, which supplies essential equipment.

103 What would you consider a minimum Insulation Reading Resistance?

Insulation Resistance must be kept above at least 1MW, the higher the Insulation Resistance the better. Companies

have their own Regulations, but most Companies only allow readings above 5MW.

104 What is a Shipboard use of Stainless Steel and the Properties that make it appropriate?

Stainless Steel could be used for Seawater Pump Shafts.

It has good corrosive properties and also good wear properties.

105 Sketch and describe a Dry Powder Fire Extinguisher.

The outer container contains a sodium bicarbonate powder. A capsule of carbon dioxide gas is located beneath aplunger mechanism in the central cap. On depressing the plunger the carbon dioxide gas forces the powder up a

discharge tube and out of the discharge nozzle.


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106 How many PPM can be Pumped in Marpol Restricted Areas?15 ppm.

107 What can you tell me about Halon Systems, with regards to new installations and existing ones?SOLAS prohibits the installation of new or portable systems in all ships from 1st October 1994 and providingexisting fixed installations and portable extinguishers remain serviceable and fit for purposes, they may remain in

place (Ref: MGN 80 (Aug 1998)).

108 What is Loop Scavenging in a 2-Stroke Engine?

Loop Scavenging is where the Incoming Air passes over the Piston Crown, then rises towards the Cylinder Head

forcing Exhaust Gases down and out the Exhaust Ports, just above the Inlet Port. The advantage of Loop is that noExhaust Valve is required.


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109 Name Main Engine Shutdowns.

Low Lub Oil PressureHigh Jacket Water TemperatureHigh Main Bearing TemperatureOverspeed

Oil Mist Detection

110 What Safety Devices are fitted to the Main Engine Crankcase?

Explosion Door/Relief Valves and Oil Mist Detectors.

111 Regarding steel, what are three types of heat treatment ?

Hardening;


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This involves heating the steel until it is 30 - 50 degrees C above upper critical temperature range ( 850 - 950

degrees C ), followed by rapid quenching. The hardest possible condition for the steel is thus produced and thetensile strength is increased.

Tempering;

This is employed to relieve quenching stresses and involves reheating the steel to around 650 degrees C ( lowercritical temperature range ). Note the higher the tempering temperature, the lower the tensile properties of the

material. Once tempered the metal is rapidly cooled by quenching.

Annealing and normalizing;Normalizing, this is where the steel is heated to around 850 - 950 degrees C depending on it's carbon content and isthen allowed to cool in air. A hard strong steel with refined grain structure is produced.Annealing, again the steel is heated to around 850 - 950 degrees C but is cooled slowly, either in a furnace or an

insulated space. A softer more ductile steel than that of normalized condition.

112 Describe the Boiler Hot Well and Cascade Tank. Why is it Fitted and how would you Trace an Oil Leak?The Boiler Hot Well is where the Condensate Drains return from the Condensor. This Condensate may be

contaminated as some of the Drains are from Fuel Oil Heating Systems or Tank Heating Systems. Normally these

Drains will pass to the Hot Well via an Observation Tank, which permits Inspection of Drains and their Dischargeto an Oily Bilge if contaminated. The Hot Well Tank is also arranged with Internal Baffles to bring about

preliminary Oil Separation from any Contaminated Fuel or Drains. The Feed Water is then passed through

Charcoal or Cloth Filters to complete the Cleaning Process. Any overflow from the Hot Well passes to theFeedwater Tank, which provides additional Feedwater to the System when required. Feed Pumps take Suction from

the Hot Well to the Boiler.

To Trace an Oil Leak to the System, various Heating Coils to Tanks would be shut off in turn until the Leakstopped, thus indicating which Heating Coil was Leaking.


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113 What is the Pressure between an Engine Fuel Pump and Injector?

250-350 bar.

114 Explain the procedure for lowering a Lifeboat with Gravity Davits.

The Lifeboat is held in against a cradle by ropes called gripes and the cradle is secured by pins. With the gripes andsecuring pins (sometimes known as harbour pins) are removed and released, the winch handbrake can be released to

enable the cradle to slide down and over the Ship's side.


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A "Tricing-in Pennant (wire)" brings the Lifeboat close to the Ship's side to enable it to be boarded.

The Bowsing Lines which fasten to each end of the Lifeboat are then used to hold it in to the Ship's side, the"Tricing-in Pennants" then being released.

A Painter is then led from the forward end of the Lifeboat and attached somewhere forward of the lifeboat on theship. Lifeboat plugs are then secured.

Once the Crew are on board the Lifeboat the bowsing lines are released and the Lifeboat is lowered to the water.The Engine is started, Falls released and then the Painter.

115 How is the Signal from the Bridge when the Helm is Moved Transmitted to the Hydraulic Rams in SteeringFlat?When the Helm on the Bridge is moved, electrical impulses are produced. These impulses are transmitted via anamplifier or control unit to the Steering Flat. In the Steering Flat, these impulses are relayed to a servomotor

(telemotor) which drives an adjusting gear and floating lever which puts the steering gear variable delivery pump onstroke, thus creating hydraulic pressure in the system which moves the Rams, thus moving the Tiller and Rudder.The Pump is only required to deliver Oil when the Helm is moved i.e. once rudder has matched the Helm Angle, theControl Lever will put the Pump Off Stroke.

116 What are the advantages of CO2 Systems compared to Halon Systems?

CO2 is more Environmentally Friendly also Halon Systems are being phased out.

117 What type of valves are ship side valves ?

Ship side valves are Screw Down Non Return valves.

118On what type of Fire would you use a Dry Powder Fire Extinguisher?

The Dry Powder can be used on all classes of Fire, but it has no cooling effect.

119 Give a Shipboard use of Aluminium Bronze and the Properties that make it suitable for this use.

Pump Impellers.It has good wear, fatigue and corrosive properties.

120 What would happen to the amps of a Centrifugal Pump if it were run with the discharge valve shut?

The amps would drop, as there would be no load on the pump.

121 What is a Water Fog based Fire-fighting Installation?

Unlike conventional sprinkler systems utilising water under low pressure in heavy large diameter pipes, the WaterFog Extinguishing System operates by using water under very high pressure in small bore pipes. This reduces theweight and volume of the system and permits easy installation on board.


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The Water Fog System produces micro-droplets of water; thus a very large cooling surface is created with only

small quantities of water. With this system the amount of water required for successful fire extinguishing is muchless than conventional sprinkler systems. This allows for the use of fresh water as the medium. Also with the

Water Fog System, the Water Fog is propelled into hidden spaces just like Halon or CO2, providing the mostreliable Fire-extinguishing.

In accommodation areas this system can use a dual-purpose nozzle which incorporates a quartazoid bulb fordetection and extinguishing.

The Water Fog System is also suitable for Engine Rooms.

122 What are the Pipes, used for Pumping Fuel around the Ship, Protected by?

Quick Closing Valves: which can be operated remotely. In most cases from the Bridge or a remote location from

the Engine Room.

123 What are the dangers of excessive lubrication in Start Air Compressors?


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There is a danger that excessive cylinder lubrication in Start Air Compressors could lead to explosions in Air Start

Lines/Manifolds.Excessive lubrication can lead to carry over with compressed air, being deposited in the Receiver then transferred to

the Air Start Manifold, where a leaking Air Start Valve may allow hot gases from combustion into the Air StartManifold, ignite the oil vapour, causing an explosion.

124 What is Boundary Cooling and the reasons for it?

It should be remembered that a Fire exists in three dimensions and therefore has six sides, therefore can betransmitted through bulkheads due to radiant heat, i.e. causing combustible materials in adjacent compartments tocatch Fire. Therefore, this radiant heat is prevented by Boundary Cooling of all sides of the compartment on fire,

using water spray hoses.

125 What does AFFF stand for and where would you use this type of Extinguisher?

AFFF stands for: Aqueous Film Forming Foam.This would be used on Class B Fires, fires burning liquids such as lubricating oils and fuels.

126 Where would you find Heat Detectors and why?Heat type Fire Detectors would be used in places such as the Galley, where other types of Detectors would give

false alarms.

127 What precautions are to be taken are returning the engine into proper service prior to bottom end bearingsurvey?Precautions to be taken before returning the engine to proper service are;The oil flow to the piston should be checked ie, there should be a good flow returning from the underside of the

piston to the sump, this is done with the lubricating pumps running and the crankcase doors off, some crankcasedoors on larger engines will have a smaller inspection door that will facilitate this. The bottom end clearance must

be within manufacturers specifications, bottom end float must be checked, connecting rod bolts must be torquedcorrectly and all locking devices fitted.

The engine must then be run on test; this will consist of first running the engine for 5 minutes with no load,checking for signs of overheating and listen for any strange noises, the engine is then stopped and crank case doors

for that particular unit removed, the bottom end bearing is felt for signs of overheated, any signs of white metalcoming away, the bottom end float will be checked. If everything is satisfactory, the engine is then run for 15

minutes and 30 minutes respectively, carrying out the same checks.When these checks have been carried out satisfactorily, the engine will then be run on 25% load for one hour, then50% and so on, keeping a close eye on temperatures and pressure and for signs of overheating until able to put onfull load, manufacturers running instructions will vary from engine to engine and should be followed.

Once satisfied that the engine is run in, it maybe returned to service.

128 What is, and where would you find, the International Shore Connection?

This is a standard size Flange which is fitted with a suitable coupling suitable for the Ships Fire Hoses. The Flangeis slotted in order to fit any shore side Fire Main and enable water to be brought on board Ship lying alongside.Usually located on the Bridge.

129 What is the Regulation regarding use of Evaporators Inshore?

Evaporators should not be used within 20 miles from Shore, due to risk of pollutants being taken into the

Freshwater System.

130 If no testing equipment was available, explain how the condition of the lubricating oil could be assessed on

board.


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If no test equipment is available on board, lubricating oil condition can be determined by a few simple tests;Crackle test for water, this is where a sample of lubricating oil is take and placed in a test tube, the test tube is then

heated, any water droplets will make a crackling noise due to the formation of bubbles, this will only detect smallamounts of water, for larger amounts, a simple settling test can be used.

TBN can be tested by placing a drop of indicator solution on to blotting paper, this being followed by a dropsampled lubricating oil in the centre of the blotting paper.

A colour change should take place around the surrounding area of the drop i.e. if the colour is red, this shows acid ispresent, green / blue show s alkaline presence.

Note: filters will also give a good indication of the lubricating oil quality.

131 How would you test a double bottom tank for watertight intergrity?

Double bottom tanks are tested by filling them completely with water, including the sounding pipe, by doing this, asmall head of pressure is applied to the tank, adjacent tanks, cofferdams around the tank being tested would be

checked.

132 What are the Advantages and Disadvantages of Alkaline Batteries?

The Advantages of Alkaline Batteries are that they retain charge on open circuit and even if discharged, it can beleft for long periods without adverse effect.The Disadvantages are that they require a greater number of cells to produce a particular Voltage.

They are also more expensive than Lead Acid Batteries.

133 List possible Impurities in Heavy Fuel Oil?

Impurities in Heavy Fuel Oil come in the form of Solids and Liquids:Solids: dirt, rust and sand

Liquids: water and sludge.

134 What Speed does the Centrifugal Brake on a Lifeboat Winch limit the Speed of Fall of the Lifeboat to?

The Centrifugal Brake on a Lifeboat will not allow the Lifeboat to fall faster than 36m/min.

135 How are star and delta connections combined to produce a star / delta starter for an electrical motor?

Star and delta connections are combined to produce a star / delta starter for an electric motor by having both ends ofeach phase for the motor starter windings taken to the starter.In the start position, the windings are connected in star, the voltage across each phase winding being 58% linevoltage, with a subsequent reduction in the starting current. The starting torque is also reduced to a third that of a

direct on line starter.As the motor then reaches normal running speed, a timer / relay will change the windings over to the delta

connection for normal running.

136 What would you do if you had a High Chloride Level in the Boiler?

To reduce the Chloride Level in the Boiler, the Boiler would be Blown Down, thus allowing Fresh Feed to theBoiler.

137 What minimum current can be regarded as Fatal?

A shock current as low as 15mA ac or dc can be fatal.

138 Name the Trips found on a Generator Circuit Breaker.

Over CurrentUnder VoltageReverse Power.


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139 How does an Oil Mist Detector Work?

The Oil Mist Detector uses a Photoelectric Cell to measure small increases in Oil Density. A Motor driven Fan

continuously draws samples of Crankcase Oil Mist through a measuring tube. An increased meter reading and anAlarm will result if any Crankcase sample contains excessive Mist when compared to either Clean Air or to the

other Crankcase Compartments. The Rotary Valve, which draws the sample, then stops to indicate the SuspectCrankcase Compartment.

The Alarm will cause an Engine Slow Down or Shut Down.

140 What is the Critical and Barred Range on an Engine?

This is where the Speed of an Engine in rpm, at which the resonant condition occurs, and is referred to as CriticalSpeed.The high stresses associated with resonant condition start to build up as Critical Speed is approached and do notcome back to a safe value until speed is beyond Critical Speed. The unsafe stresses either side of Critical Speed are

known as Flank Stresses, this is known as the Barred Speed Range.The Engine must not be continuously operated at speeds within the Barred Range.

141 How is crankshaft main bearing clearance measured?

Crankshaft main bearing clearance can be measured in the following ways;By using a set of feeler gauges ( swedish feelers for better access ).

By means of lead wire, the main bearing cap is removed, as is the top shell, a piece of soft lead wire ( @ 0.5mmthick ) is then placed on the crankshaft journal. The shell and bearing cap are then replaced and torqued to the

makers setting. The cap and shell are then removed again and the lead wire is gauged using a micrometer to get theclearance.Another method is by measuring the crankshaft diameter and then the inside diameter of the bearing shell, this is

probably the most accurate but can prove to be the most difficult.

142 What could start a Scavenge Fire?

The main cause of a Scavenge Fire is the Fouling of Scavenge Spaces by the blow by of products of incomplete

combustion caused by incorrect cylinder lubrication, faulty fuel injection equipment, accumulation of such mixturesin the Scavenge Space can be set alight by sparks or flame blow by.

143 Sketch and describe the Mechanical Foam type Fire Extinguisher.

The outer container is filled with water. The central container holds a carbon dioxide charge and a foam solution.A plunger mechanism with a safety guard is located above the central container. When the plunger is depressed, the

carbon dioxide is released and the foam solution and water mix. They are then forced out through a special nozzle,which creates the Mechanical Foam. This Extinguisher has an internal pipe and is operated upright.


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144 With regards CO2 Extinguishers, what testing and maintenance is carried out?

Being a pressure vessel, the CO2 Extinguisher is initially tested to 207 bar and after every ten years and after twosuch tests, every five years.Carbon Dioxide Extinguishers should also be weighed every six months to check for leakage.

145 What are the Safety Devices fitted to an Air Compressor?

Low Lub Oil Pressure Shut DownHigh Air Temperature Shut Down

1st Stage Relief Valve2nd Stage Relief Valve

A Fusible Plug is fitted after the 2nd Stage Cooler, Set at 120CIf Water Cooled, a Jacket Water Safety Valve is fitted.

146 Where would you expect to find a Soda Acid Extinguisher (Water)?


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Accommodation areas.

147 What is the Purpose of a Fusible Plug on an Air Receiver and at what Temperature is it Designed to Melt

The purpose of the Fusible Plug is to act as a Safety Feature to Release Compressed Air from the Receiver in theevent of a Fire in the Vicinity. The Fusible Plug is designed to melt at 150C.

148 What is meant by Preference Tripping?

Preference Tripping is the tripping of non-essential loads when an overload condition occurs on a Generator.If a Generator Overload develops the Preference Trip Relay operates an Alarm and acts to trip selected non-

essential loads. These loads may trip at set intervals depending on how essential the load is, i.e. 1st trip 5 seconds,2nd trip 10 seconds

149 What are the Properties of Heavy Fuel Oil?

The Properties of Heavy Fuel Oil are: High Viscosity, Long Ignition Delay i.e. Low Cetane Index

150 What would prevent Water rushing out of the Boiler if the Gauge Glass were to break?

A Ball Valve is fitted below the Gauge Glass Tube to shut off the Water.

151 Why is an Alarm Sounded when CO2 is released into the Engine Room?

An Alarm is sounded to inform personnel in the Engine Room that the release of CO2 is imminent. The type ofAlarm will be visual and sound different from Engine Room Alarm and General Alarm.CO2 can not support Life.

152 Explain the Bilge System from Bilge Wells to Overboard

The Bilge Pump (Positive Displacement Pump) takes Suction from the Bilge Well via a Strum Box, then via aStrainer before entering the Pump where it is then discharged to the Bilge Holding Tank.

From the Bilge Tank the Oily Water Separator takes Suction, Bilge Water passes through the Separator beforebeing discharged overboard via 15ppm Monitoring Unit, which will automatically stop the Oily Water Separator

Pump and give an Alarm if the Oily Water Mixture exceeds 15ppm.

153 How would you test shell plating for watertight intergrity?

Shell plating can be tested for watertight integrity by a vacuum test, where in drydock, a sealed box is placed over

welds and evacuated of air, loss of vacuum showing leaks, welds on ships plating may also be x-rayed to check theintegrity of the weld.

154 Briefly describe the test for chlorides,

Phenophalein alkalinity test;

Take a 100ml sample of boiler feed water, add 1ml of phenophalein indicator, the solution should turn pink. Thenadd drops of sulphuric acid drop by drop until the colour turns clear;PPM= 10x drops added

Chloride test;Using the above solution, add 2ml of sulphuric acid, then2 20 drops of potassium chromate indicator, then adddrops of silver nitrate, drop by drop until the colour turns brown,PPM Chlorides = 10 x drops added


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155 How is Lub Oil Temperature Controlled?

Lub Oil Temperature is Controlled by means of a Thermostatically Controlled Valve, which will allow Lub Oil toby-pass the Cooler when too cold and divert Lub Oil through the Cooler when too Hot. Pre-set Wax Elements

being incorporated in these Valves for this purpose.

156 When would a Star/Delta Starter be used on a Motor?

Where a slow moving high inertia load is involved the starting time must be considered because of the heatingeffect of the starting current and in this case a Star/Delta Starter would be used.The Star/Delta Starter first connects the Starter Windings in Star and when running changes over to Delta. The Starconnection results in about 58% Line Voltage being applied to each Phase with therefore a reduction in Starting

Current. The Starting Torque is also reduced to about 1/3 of its direct on-line valve.

157 What is the Purpose of a Volute Casing in a Turbo Charger?

The purpose of a Volute Casing in a Turbo Charger is to change the Air Velocity in to Pressure. It also ensures aConstant Velocity of Air leaving the Turbo Charger by accommodating for the gradual increase in quantity of Airthat builds up at the circumference of the Compressor.

158 Explain your Company's Bunkering Procedures.

Most Companies will have a Bunkering Procedure which will consist of a check list containing Procedures such as:

Ensure vessel is securely mooredScuppers are plugged

There are communication between both partiesNo smoking signs placedNo hot work is taking place in the vicinityOil spill gear is available

Correct valves are opened for bunkeringThe overflow tank is emptyThis check list is then signed by both parties plus the Chief EngineerThe time of bunkers starting and finishing are then recorded

The amount to each tankPlace of bunkering

Type of Fuel Oil Bunkered, this is also recorded in the Oil Record Book.

Note: Before Bunkering a set of soundings should be taken; also during Bunkering to ensure Fuel is going tocorrect tanks; and at the end of Bunkering.Samples of Fuel Bunkered should be taken throughout Bunkering for Analysis.

159 What is the Bilge Injection Valve?

The Bilge Injection is a valve that enables the Engine Room Bilges to be pumped out directly overboard in the

event of an emergency such as flooding. The valve is normally fitted to the end of a branch connection with themain sea-water suction line. This enables large main sea-water cooling pumps to be used as a bilge pump in an

emergency.


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160 Describe how a Self Excited A C Generator would work.

The Self Excited A C Generator basically consists of a Synchronisis Generator, where the 3-phase supply isgenerated, an A C Exciter and a Rotary Rectifier and a Static Excitation Device.The Rotating Diodes change A C into D C for the D C Excitation Current, which is supplied through Brushes. TheExciter in conjunction with the A V R is used to monitor the correct Voltage under Load Changes.


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161 How do you carry out a Face Seal Check on a Breathing Apparatus Set?

Don Face Mask, tighten straps properly and turn air supply on. Then switch air supply off and breath in, the maskshould stick to face. Note, pressure gauge should not drop rapidly either. Switch air supply back on.

162 What are Crankcase Pressure Relief Valves for?

These Valves act as a Safeguard to relieve excessive Crankcase pressures, which may occur from Oil Vapourigniting in the occurrence of an Engine Component overheating. They also prevent flames from being emitted from

the Crankcase and must also be self closing to stop the return of atmospheric air into the Crankcase.


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163 What causes Black Smoke from Combustion i.e. in the Exhaust?

Black Smoke would indicate Faulty Fuel Injection Equipment or it would indicate Insufficient Air Supply.

164 What is the purpose of the Cylinder Relief Valve and Operating Pressure?

The Cylinder Relief Valve is designed to Relieve Pressures in Excess of 10%-20% above normal.

The Operation of this Device Indicates a fault in the Engine, which should be discovered and corrected

immediately.

165 What type of Clutch is used on an Electric Windlass?

The type of Clutch used is a Dog Clutch.

166 What is the duration and range of a 136L Trolley Foam Extinguisher?

The duration of a 136L Foam Trolley Extinguisher is 15 minutes approximately with a range of around 18m.


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167 How do you Start Up, run Parallel a Generator?

First check Engine Oil Levels, such as Lub Oil Sump, T/C Oil Level, Governor Oil Level, Rocker Arm Bank OilLevel (if fitted).

Check Jacket Water Header Tank LevelEnsure Indicator Cocks are Open, Start Lub Oil Priming Pump then bar Engine over (ensure Turning Bar is

removed).Kick Engine on Air. Close Indicator Cocks.

Start the Engine.Check all Parameters are correct: Lub Oil Pressure/Temperature, Jacket Water Temperature/Pressure, Check SeaWater Cooling Pressure and Rocker Arm Lub Oil Pressure.Allow Engine to warm up and when satisfied that everything is okay, Engine may be paralleled as follows:

Ensure the Voltage of the Machine to be paralleled is the same as the Bus-bar Voltage. Ensure the Frequencies ofboth Machines are the same (the Frequency of the Incoming Machine can be adjusted using the Speed Control).Select the Machine to be paralleled on the Synchroscope Selector.The Synchroscope should then start to Rotate, it should be rotating in a clockwise direction slowly. If it is rotating

in an anti-clockwise direction, this means the speed of the Incoming Machine is too slow or if it is rotating FastClockwise, the speed of the Incoming Machine is too fast, this is adjusted using the Speed Control.When the Needle of the Synchroscope is Rotating in the Clockwise Direction Slowly, the Breaker of the IncomingMachine should be Closed. When the Needle of the Synchroscope is at the Five to Twelve Position, this will allow

the Incoming Machine to take a slight amount of load when coming on the Switchboard and also prevent the

Machine tripping on Reverse Power.The Load is then shared equally between both Machines.

168 What sort of Starting Current do you get with a Direct On-Line Starter?

6-8 times Full Load Current.


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169 What would happen if the Lub Oil Pressure dropped to Low on a Pump?

If the Lub Oil Pressure were to drop too low on the Lub Oil Pump, the Stand By Lub Oil Pump would cut in.

170 What can you do to prevent Scavenge Fires?

Conscientious maintenance of the Engine and regular inspection and cleaning of Scavenge Air Spaces will help

prevent Scavenge Fires.

171 How can cylinder liner wear be kept within limits given by the manufacturer?

Cylinder liner wear may be kept within engine makers limits by using good quality cylinder lubricating oil andfuels, lubricating oils with a high TBN.

Running the engine within it's limits.Keeping good control of jacket water temperature and chemical treatment.

Also keeping a good maintenance schedule.


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172 What is meant by Protection Discrimination?

This is the ability of a Protection System to disconnect only Faulty Circuits and to maintain the Electrical Supplies

to Healthy ones.Discrimination is achieved by co-ordinating the Current Ratings and the Time Settings of the Fuses and Over-

current Relays used between the Generator and the Load.The Devices nearest the Load having the lowest Current Rating and shortest Operating Time; those nearest the

Generator having the highest Current Rating and longest Operating Time.i.e. a Motor Fault on a Centrifugal Pump would not cause the Generator Breaker to Trip.

173 State why some centrifugal pumps have a double volute casing or a diffuser ring?

Some centrifugal pumps have a double volute casing to provide a rotational balance and this reduces wear on radialbearings.A diffuser ring is fitted to high-pressure centrifugal pumps to covert the kinetic energy into pressure, this ring isfixed in the casing around the impeller in such a way that passages are formed around the vanes.

174 When working on Batteries, what precautions should be taken?

Ensure the space is well ventilated, do not smoke or use naked lights and also wear protective clothing such as

apron, gloves and face shield.

175 Halon Fire-fighting System, describe it.

In a Halon Fire-fighting system, Halon bottles are strategically placed around the Machinery Space. The amount ofHalon (1301) required for Fire-fighting is very little. Each bottle has its own definition mechanism. This is

operated from a remote location outside the Machinery Space.

On opening the Halon release cabinet, this will sound the Halon Alarm in the Engine Room, which will letpersonnel know that the release of Halon is imminent and that the Space should be evacuated. Ventilation to the

space should then be stopped and space sealed. Before release of Halon, all personnel should first be accounted for.

176 What does SOLAS stand for?

Safety of Life at Sea.

177 How would you know a Refrigeration System was Undercharged?

Undercharge will show as a Low Compressor Pressure and large bubbles in the Liquid Line Sight Glass.

178 What Loads are considered Non-essential?

Loads considered as Non-essential are: Air Conditioning and Ventilation, Laundry, Galley, Refrigeration andDeck Equipment.

179 Crankcase Inspections: Frequency, Procedure and Reasons they are carried out.

The Frequency may vary from different Engine Manufacturers but is roughly around 5000 hrs.Also Inspections are carried out after any work has taken place in the Crankcase.Procedure is as follows:

Remove Crankcase Doors from both sides of the Engine. Relief Valves can be checked at the same time as theDoors are off.Inspect condition of all bolt locking devices, replace any damaged components.Turn Engine over using Turning Gear, ENSURE NO-ONE is in Crankcase while doing this and that the Indicator

Cocks are Open, check condition of Camshaft Drive Gears.


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Start Main Lub Oil Pump and check Oil Flow from Bearings and Piston Cooling Parts. Check for any Leakage

from Internal Oil Pipes and Galleries.Check for any damage of Camshaft Lobes

Check for any evidence of Water Leakage from Lower Cylinder Liner "O" Rings.Replace any damaged Crankcase Door Joints.

Record any Defects.

180 How do you ensure that Batteries are always in good working order?

Where Lead Acid Batteries are used, they require a constant trickle charge, but for both types of Battery a regularcharge up is necessary.Check state of Battery using a Hydrometer; Lead Acid - S G 12701285 Alkaline is 1190 but S B for AlkalineBatteries does not change much during charge or discharge.

Ensure cells are covered with electrolyte, if not, top up with distilled water.Keep batteries dry and clean Terminals should be smeared with Petroleum Jelly.

181 What would cause an Excessive High Pressure in a Refrigeration System?

Faults that would cause over pressure are; lack of cooling to the condenser, remedy is to increase cooling waterflow through the condenser, or unblock any fouling on the cooling water side of the condenser.Choked expansion valve, which could be caused by dirt impurities in the system, or freezing of the expansion valve,

caused by water in the system, remedy is to clean expansion valve, clean system of impurities, rid system of

moisture.

182 How often is the Emergency Steering Tested?

Emergency Steering is Tested at least once every 3 months.

183 What is meant by the Term, Type Ex'p'?

Ex'p' = Pressurisation.

This is where Equipment is Pressurised to prevent any gases entering Equipment.

184 Describe three on board tests for main engine lubricating oil.

The flow stick test; this is where the viscosity of the lubricating oil is tested.

Two samples of oil are used for this test, one from the system, and the other, fresh new oil. The flow stick containstwo reservoirs, one for the system sample and one for the new fresh oil, these reservoirs are filled and the samples

are allowed to reach the same temperature.The flow stick is then tilted from the horizontal and the oil flows down two parallel channels, when the fresh oilreaches a reference point, the flow stick is returned to the horizontal.The distance traveled by the used system oil is compared to that of the new, fresh oil and if the used oil is between

the two used oil comparison points, the used system oil is still in good condition.

The % water in oil test is used to give an indication if any of water in the lubricating oil, here a fixed amount of oilis sampled from the system, which is 5ml and placed in a capsule where there is a 15ml solution of white and

reagent. A lid incorporating a pressure gauge that is calibrated to read % water in oil is then screwed onto thecapsule to form an air tight seal.

The capsule is then shaken vigorously for 1 minute, then left to stand, any water in the lubricating oil will react withthe white spirit and reagent causing a rise in pressure that will be read on the pressure gauge as % water in thelubricating oilSee Sketch

Another test is; Microbiological degradation of oil test, this test will give an indication of an infestation ofmicrobiological organisms in the lubricating oil.The test makes use of slides that are coated with a special gel, which is dipped in the sample of lubricating oil, the

slide is then placed in a test tube, sealed and left to incubate, any growth that comesAbout in the incubation period is then compared to a chart to indicate any infestation by microbiological organisms.

185 What is Cross Flow Scavenging


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In Cross Flow Scavenging, the Incoming Air is directed upwards, pushing the Exhaust Gases before it. TheExhaust Gases then travel down and out of the Exhaust Port. Advantage is no Exhaust Valve.

186 What would you do if the Lub Oil Temperature started to Rise?

Inform Bridge and reduce load on Engine, Investigate Problem, which could be a Fouled Cooler.

187 How can you Reverse the Direction of a Motor?

By swapping any two supply line connections over.

188 At what Temperature does the MCA state that Fuels must be kept in Storage Tanks?

14C under their Flash Point.

189 What Safety Equipment should there be at a Bunker Station.

Safety Equipment that should be found at a Bunker Manifold are a Foam Fire Extinguisher, Oil Spill Gear such as

Spill Absorbent and there should also be communications of some sort.


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190 How would you test a watertight door for watertight intergrity?

A watertight door is checked for watertight integrity by means of a simple hose test, but on construction are

hydrostatically tested.

191 With regards flammable mixtures, explain lower and upper flammable limits.

The meaning of lower flammable limits is where the mixture is below the flammable range and is too lean and

incapable of burning.As where upper flammable limit is where the mixture is too rich and incapable of burning.Between these limits is the flammable range.

192 What is the function of the High Pressure cut out in a refrigeration system?

The function of the HP cut out is to shut the compressor down in the event of an over pressure on the condenserside of the compressor, and can only be manually reset.

193 Briefly explain how High Expansion Foam is produced.

High expansion foam is produced by means of a Foam Generator, where from Foam Concentrate and Seawater,

1000 times quantity is achieved. The generator blows air through a net sprayed with foam concentrate and water.

The vastly expanded foam is then diverted away to the space to be protected. The foam is an insulator and anabsorber of radiant heat; it also excludes oxygen from the fire.

194 What precautions should be taken when working aloft?

Where possible, staging or a ladder should be used and secured firmly. A safety harness and lifeline must be used. Ifpossible a safety net should be rigged.Tools should be carried up in secure containers or belts specially designed for carrying tools to prevent them falling

and causing injury to anyone.The area below the work site is to be roped off with warning signs, people working aloft.Care should also be taken when working aloft that tools are placed in secure positions to prevent them dropping onanyone.

Hazards should be identified, such as, ships whistle, radars, antennas, which should all be isolated while aloft anddo not operate signs placed.

195 How is Leakage in the High Pressure PipeLine between the Fuel Pump and Injector, detected?

Leakage between the Double Skin/Wall of the High Pressure PipeLine between the Fuel Pump and Injector isdetected as this space between the Double Skin/Walled Pipe is led via Drain Line to a Small Tank fitted with a

Level Alarm.

196 What is the Importance of "M" Notices?

M" Notices are important as they convey very useful information such as:

Merchant Shipping Notices (MSNs): which will only be used to convey mandatory information, which must becomplied with under British Legislation.Merchant Guidance Notes (MGNs): which will provide advice and guidance to relevant parties in order to improvethe Safety of Shipping and of Life at Sea.

Marine Information Notes (MINs): which will provide information to a more limited audience such as TrainingEstablishments or Equipment Manufacturers.

197 What Limit does the MCA state that the lower limit of Flash Point of Fuels used on board Ship should be?

65C

198 Why is Overlap necessary on Air Start Valves?


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Overlap is necessary as if there was no Overlap it would be possible for the Engine to stop in a position where no

Valves are Open, i.e. unable to Start.

199 What is the Principle Operation of a Flame Detector?

As Flame has a characteristic Flicker Frequency of 25Hz, use is made of this fact to trigger an alarm. Flickering

radiation from flames reaching the detector lens/filter unit, which only allows infra-red rays to pass and be focusedupon the cell. The signal from the cell goes into the selective amplifier, which is tuned to 25Hz, then to a time

delay unit (to minimise incidence of False Alarms) then to an alarm circuit.

200 What is the composition of inert gas after the Scrubber Tower on an Inert Gas System.

Oxygen: 0-1% (Alarm at 5%)Carbon-monoxide: 0Carbon Dioxide: 14-15%

Nitrogen: 85

201 Sketch and describe the Battery CO2 System.

The system shows a Battery CO2 System for a Machinery Space. On opening the release cabinet, this will sound

the alarm in the Engine Room, warning personnel that release is imminent and that they should vacate the Engine

Room. Opening of the cabinet will also stop ventilation. Before release of CO2, a head count must be done to seeall personnel are accounted for and the Machinery Space must be sealed.When the operating handle is pulled, this opens a set of CO2 starting bottles, which in turn supply CO2 to an

operating piston via a safety valve. The piston in turn allows the battery of CO2 bottles to be released to theEngine Room. This is known as a "One Shot" method.


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202 Where are CO2 Extinguishers not permitted ?

CO2 Extinguishers are not permitted in the accommodation, because of their oxygen depleting effect in enclosed

rooms.

203 What %/Ratio Halon is required to extinguish a Fire in a Compartment?

5%

204 Why are CO2 Extinguishers not permitted in the accommodation.

Because if used in a confined space, it could be lethal.

205 What is the purpose of the Crankcase Oil Mist Detector?

The purpose of the Oil Mist Detector is to detect the build up of Oil Mist in the Crankcase, generated from a HotSpot. The Detector will then give an Alarm, either Shut Down or Slow the Engine Down and give and indication of

which Unit the Oil Mist is generated.


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206 How would you test a hollow rudder for watertight intergrity?

A hollow rudder would be tested in drydock by filling the rudder with water and checking it for leaks, a smallpressure may be applied to aid this, ie a head of pressure from a stand pipe of 2metres or 0.2 BAR air pressure.

207 In an air conditioning system, describe the conditions that could lead to legionella growth and list the

precautions in the maintenance of an air conditioning system to reduce the risk of legionnaires disease beingcontracted.

The conditions that could lead to legionella bacterial growth are dirty air filters at the air inlet, pools of water belowthe evaporator that become stagnant, or water becoming stagnant in the humidifiers of the water type.Precautions necessary in the maintenance of AC systems to reduce the risk of legionnaires disease

being contracted is to ensure the system is clean, i.e. . provide adequate drainage below evaporators for the removalof water. Weekly inspections of the system and cleaning of air filters, when necessary with super chlorinatedsolution, drainage areas also being cleaned with this solution at least every three months. If using water typehumidifiers, regular sterilization of them is required. ( steam humidifiers being the preferred choice ).

208 Give a Shipboard use of Cupro-Nickel and the Properties that make it suitable for this use.

Heat Exchanger Tubes.

It has good corrosive qualities and very good heat transfer qualities.

209 What is the Pressure of a Start Air Receiver?

25-40 bar depending on the type of Engine.

210 How is the Bilge Injection Valve brought into Operation?

To bring the Bilge Injection Valve into operation during an Emergency, the Valve is opened fully and the SeaInjection or Suction Valve is fully closed. After it is established the Bilge Injection Valve is capable of lowering

the water level in the Engine Room, the Sea-water Injection Valve or Suction Valve may be opened slowly. Thisshould be done in stages so that the Tank Tops are not pumped dry, as this would cause the sea water pump to loosesuction.

211 What is Compression and Explain what Happens.

Compression is where the Air that is drawn into the Cylinder is compressed on the upward Stroke of the Piston,both Inlet and Exhaust Valves being closed on this Stroke. As the Air is compressed by the Rise of the Piston, the

Air Temperature is consequently raised. As the Piston reaches the TDC, Fuel is Injected, causing Ignition and veryrapid rise in Pressure of the Gases forcing the Piston down.

212 What type of Fire Detection Equipment did you have on board your Ship?

Flame Detector

Smoke DetectorHeat Detector

213 What testing and maintenance is done regarding Soda Acid and Foam Extinguishers?

The extinguisher containers are pressure vessels, therefore require testing.Containers are initially tested to 25 bar every year for five years and thereafter at four yearly intervals to 20 bar.On Soda Type Extinguishers 20% of contents should be discharged per year and replenished with Foam Type 50%.

Where practical the operating mechanism of portable extinguishers should be examined every three months.

214 What would be your first indication that there was water in the Sump?

Your first indication would be from your Lub Oil Purifier.Or even possibly from water in Lub Oil Tests, if done Regularly.

215 Sketch and describe a CO2 Extinguishers.


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A CO2 Extinguishers consists of a very strong container that is used to store liquid carbon dioxide under pressure.

A central tube provides the outlet passage for the carbon dioxide, which is released either by a plunger-bursting discor a valve operated trigger. The liquid changes to a gas as it leaves the Extinguisher and passes through a swivel

pipe or hose to a discharge horn.

216 On what type of Fire would you use a Soda Acid Extinguisher (Water)?

This type of Extinguisher would be used on Class A Fires: Fires burning wood, glass fibre, upholstery andfurnishings.

217 Explain how the Emergency Generator starts up in the Event of Total Power Failure.

The Start-up of the Emergency Generator is initiated by an Electrical Relay, which monitors the normal MainsPower Supply. Falling Mains Frequency or Voltage causes the "start-up" relay to operate the Generator StartingEquipment. The Prime Mover may be electrically cranked from it's own 24V battery and starter motor or air started

from it's own air reservoir fitted local to the Generator Engine. A manual start-up may also be initiated by pushbuttons in the Main Control Room and in the Emergency Generator Room.Also when power loss occurs, the Breaker feeding the Emergency Switchboard from the Main Switchboard opens.This Breaker is interlocked with the Emergency Generator Breaker, which is normally open under normal

circumstances, but in the event of Total Power Failure, this breaker will close when the Breaker feeding the


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Emergency Board from the Main Board opens. Thus the Emergency Generator will feed the Emergency

Switchboard.

218 What are the two Brakes on a Lifeboat Winch?

The two brakes on a Lifeboat are a centrifugal brake and a weighted brake known as a "Dead-Man's Brake" i.e.

once you let go of the braking lever, the brake will come into action stopping the fall of the Lifeboat.

219 What would you do if you had High Jacket Water Cooling Temperatures?

Inform Bridge and then reduce Engine Load and Investigate Problem:Which could be insufficient Flow through Cooler due to Fouled Cooler or Faulty Thermostatic Valve.

220 What are the two types of CO2 Fixed Installations used on board ships for Fire Fighting?

The two types of systems are: Battery System and Bulk System.

221 Sketch and describe the Chemical Foam type of Extinguisher.

The main container is filled with sodium bicarbonate solution and a long inner polythene container is filled with

aluminium sulphate. The inner container is sealed by a cap, held in place by a plunger. When the plunger is

unlocked by turning it, the cap is released. The extinguisher is then inverted for the

class 4 eoow

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