Certification Assistance for Marine Engineers

Canadian First Class ME 
Engineering Knowledge - Motors (3)

In Canada, Transport Canada administers the Marine Engineering examination process; visit the Training Page for details on the process. The actual exam consist of nine (9) questions randomly drawn from a question bank of the various subject. Six (only) must be answered in a 3.5hrs time frame. The exam questions are similar to these, presented below, and are drawn heavily from similar question in the Reed's Marine Engineering series of books. 
Brought to you by www.dieselduck.net comments to [email protected]
Transport Canada has ask us to advise users of this webpage to keep in mind that these questions are not the exact questions found in their exams. Martin's Marine Engineering Page - www.dieselduck.net is not affiliated with Transport Canada and these questions have been gathered from various sources.

A visitor reported that the following questions showed up on his exam in June 2007...

1. Describe a centrifugal separator; what is the difference between purifier and clarifier? Why is the water supplied. Why is the oil preheated?

2. Describe the supercharging of a four stroke diesel engine. Explain the difference between pulse and constant pressure supercharging.

3. Describe a fuel oil system suitable for a marine Donkey boiler. Provide full explanation of all the parts involved.

4. What limits the power of a diesel engine? What would happen if we only increase the amount of fuel injected in cylinder per cycle?

5. Which are the conditions for a good combustion? What would be the reasons for : black smoke, white smoke, blue smoke. What problems would you suspect and how would you remedy them?

6. In a cylinder head, sometimes cracks occur. Why and where are they likely to occur? How would you identify a cracked cylinder head?

7. How the timing is done for a fuel pump, exhaust and inlet valve for a four stroke diesel engine? Provide a full explanation.

8. If you would have to use sea water in a boiler, what precautions would you take? How would you check the density, how would you maintain it within the limits and which are these limits?

9. How would you inspect and overhaul an air starting bottle? Where would you find corrosion and why?

M001.  On a 2-stroke diesel engine why is a scavenge pump used?  Describe an air scavenge system using a reciprocating pump.  How is it driven.  How much greater is the capacity of the pump as required by the engine and why?



M002.  What would be the advantage of a two stroke diesel engine having a direct drive to the scavenge pump, or having an indirect driven rotary scavenge pump.  Would there be any heat loss to the exhaust gases?


M003.  Describe a supercharger and it's operation.  What is it's effect on the following:

a) pressures

b) temperatures

c) mean effective pressures

d) power

e) thermal efficiency

f) fuel consumption


M004.  What is meant by supercharging?  How is it accomplished?  What is it's effect on pressures and temperatures.


M005.  What is the definition of a supercharger?  Describe the different methods of supercharging a diesel engine. State the advantages.


M006.  Describe a system of super or pressure charging used by a 4-stroke marine diesel engine exhaust gas turbocharger. What is meant by "overlap" as applied to this type of system. Why is overlap necessary?



M007.  Give a considered and reasoned account for the types of failure to the main engine turbo-charger listed below.

a) a fractured turbine casing

b) the rapid development of a severe vibration problem

c) the abrupt stopping of the machine during normal operation while accompanied by a great deal of noise


M008.  Discuss the advantages and disadvantages of port vs valve scavenging.  Explain how uniflow scavenging is effected.  What types of engines are suited to this form of scavenging?


M009.  Describe a scavenge pump for a two stroke engine. What is it's capacity and operating pressure?  Is water cooling necessary?

REF:   83


M010.  Describe a turbo charger you are familiar with.



M011.  Describe a rotary scavenge pump.  How does reverse operation work?



M012.  Sketch and describe a rotary lobe type blower suitable for supplying air to a large reversible diesel engine. Describe the means of controlling air when the engine is reversed.


M013.  Sketch and describe a direct-dirven blower.  What arrangements are made for astern running?


M014.  Sketch and describe an exhaust gas turbocharger.  Why is exhaust outlet temperature higher than the cylinder exhaust temperature


M015.  Describe fully the construction and operation of a scavenge pump for a two cycle diesel engine.  Is cooling necessary and at what air pressure does the pump operate?



M016.  Sketch and describe the under-piston method of supercharging in a 4-stroke diesel engine.  What effect does this have on efficiency?  What are the faults of this system?


M017.  Discuss the causes and prevention of scavenge fires.


M018.  Why in some cases is scavenge air allowed to flow into the cylinder after the exhaust closes?  Show what arrangements are made to provide for such a flow.


M019.  What are the most influential physical characteristics required of the principal bearings for high speed, medium speed and slow speed diesel engines.  Who do the following details relate to these characteristics:

a) thin bearing shells

b) fluid film lubrication

c) surface finish

d) alignment


M020.  Describe the construction of a large, double acting diesel engine.  How is it strengthened


M021.  Describe a large two stroke opposed-piston diesel engine.  State the advantages and disadvantages of same.


M022.  Describe with aid of sketches the following types of bedplates as used for a large I.C. engine:

a) bedplate cast in section

b) fabricated steel bedplate

State the stresses to which these bedplates are subjected and explain  how bedplates are secured to the hull of the ship.


M023.  Sketch a transverse section through an engine in way of the tie-bolts, showing how the whole structure is held together.  Give reasons why tie-bolts are situated as shown. Explain why tie-bolts are not fitted in all engines.


M024.  Sketch and describe a tie bolt.  How is it fitted in a large diesel engine and why?  What type of diesel engine does not require tie bolts and why?


M025.  How is a crankshaft constructed.  What physical tests are done on it?



M026.  Sketch the following types of engine crankshafts:

a) solid forged

b) completely built up

c) semi built up

State what materials are used and the relative merits.  Give the normal shrinking allowances.


M027.  Sketch and describe a built-up crankshaft.  What materials are used and what tests are carried out on the materials?  What stresses are crankshafts subjected to?


M028.  If marks resembling flaws were noticed in a shaft of a crankpin, what tests would you prefer to see if it is suitable for use?  What would cause the flaws?



M029.  Discuss the principal forces a large diesel engine crankshaft must withstand while in service and how the stresses resulting from these forces are kept within acceptable limits by good design and operation criteria. Discuss the manner in which the crankshaft may be overstressed and the difficulties arising there from.


M030.  What is torsional vibration in a crankshaft?  What are the dangers of running at critical speed and what is done to prevent it?



M031.  Should you find a flaw on a diesel engine crankshaft when inspecting explain the test done to determine the seriousness of the flaw.  Give reasons how flaws occur.



M032.  Sketch and describe the method of securing the piston rod to the piston of a large diesel engine of:

a) 4 stroke single acting type

b) 2 stroke double acting type


M033.  Sketch the lower piston crosshead arrangement as adopted in Doxford opposed piston engine.  How is the piston rod attached to the crosshead and explain why this method is used?



M034.  Describe the various cams found on a four-stroke engine.  How are they fitted to the shaft?  What would be the effect of weardown, and how could this be corrected?


M035.  What is the calorific value of diesel fuel?  Give the percentages of heat losses and for useful work.  State the methods of heat recovery.


M036.  Discuss the purpose of purifying fuel oil.  Sketch a two centrifuge fuel oil system including settling tanks, double bottom tanks, etc.  What routine service is required of purifiers?


M037.  Describe the action of any type of oil separator you are familiar with.  What is the difference in operation in a separator and a clarifier?  Why is the oil preheated?  What is the reason for priming with fresh water?


M038.  Sketch and describe a common rail fuel system as fitted to a diesel engine.  How is delivery of the fuel controlled?


M039.  Why are fuel pumps located near injectors?  If fuel lines are unequal length how do you balance fuel delivery? What adjustments are made to adjust for long lines?



M040.  Sketch and describe a fuel pump plunger helix release type as fitted for solid fuel.  State type of material used and explain how this type of pump is driven and regulated.



M041.  Sketch and describe a fuel injection pump suitable for an airless injection diesel engine (Bosch type).  Describe fully how it operates and how the gravity of fuel is regulated.  State the materials it is made of.


M042.  Sketch and describe a jerk (Bosch type) fuel pump and mention material used.  How is the pump driven?  How does the helical plunger control the fuel delivered?





M043.  Explain why abrupt, precise injector action is required and how it is achieved.  Explain why injector action deteriorates progressively with time in service.


M044.  What factors govern the power output developed by a large diesel engine?  Would it not be possible to just inject more fuel into the cylinder in order to obtain more horsepower?


M045.  State the necessary alterations required to convert a diesel engine to burn high viscosity bunker fuel from low viscosity fuel.  State advantages and disadvantages of high viscosity fuels.


M046.  Describe what would be necessary inside a diesel cylinder for good combustion.  What is the cause of:

a) black smoke

b) white smoke

c) blue smoke

Give remedies for each.


M047.  Sketch a draw card and light spring diagram from a 4-stroke diesel engine.  Why are these cards taken?  What do they show?



M048.  Draw a timing diagram for a 4 stroke diesel engine and produce an indicator diagram


M049.  Sketch the timing diagram of a 2-stroke marine engine showing the crank angles at essential points on the diagram.


M050.  Sketch an indicator card of a single acting 4-stroke diesel, listing the various pressures and temperatures.  Draw in dotted lines showing the effects of a leaky exhaust valve.


M051.  Draw an indicator card for a four stroke diesel engine showing pressures and temperatures at critical points.  Show on duplicate card by dotted lines, the effects of leaky piston rings, early fuel injection and late fuel injection.


M052.  Sketch and describe an indicator card with normal compression pressure and high firing pressure.  What results would you expect?  What is the cause of low compression? What is the couse of high compression?


M053.  Sketch an indicator diagram for a diesel engine showing the effects of supercharging.


M054.  In reference to Doxford engines:

a) Explain the advantages claimed for opposed piston engines.  Why do two pistons of such an engine have different stroke lengths.

b) Outline the difference between a diesel engine and opposed piston diesel engine.

c) Describe the cycles and principals of an opposed piston engine. 

d) What are the advantages and disadvantages of this type of engine?

e) Sketch an indicator card you would expect to get from this type of engine.


M055.  Draw an "out of phase" diagram for a large 2-stroke slow speed cycle engine.  Describe in detail the part of the cycle showing on this diagram.  Using the diagram explain the effects of burning high and low grade fuels  (when fuel injection timing is not altered).  Explain how good ignition and combustion can be obtained when using low grade fuel.


M056.  Describe the principle of operation and sequence of four stroke and two stroke diesel engines.  Give timing diagrams, degrees and the make of each engine.


M057.  Describe the firing order of 6 cylinder 2-stroke and 4-stroke engines.  Give the reasons that govern the firing order of an engine.



M058.  Explain how the fuel pump and exhaust and inlet valves are timed on a four stroke type engine.



M059.  Explain how cylinder powers can be balanced in a medium speed engine.  What effects will be noted if an engine is operated unbalanced for long periods of time?


M060.  What are the causes and remedies of a multi-cylinder engine having one exhaust temperature higher than normal?


M061.  When using the following terms, what do they mean:

a) low speed and heavy duty diesel engine

b) medium speed and heavy duty diesel engine

c) high speed and heavy duty diesel engine

Indicate what would be the R.P.M. for each.  What advantages and disadvantages would each one have?  Where would these units be best employed?


M062.  What are the pressures and temperatures in a four stroke diesel engine running full speed at the following critical instances:

a) air at begining of compression stroke

b) air at end of compression

c) burning gases at end of combustion period

d) burning gases at end of expansion period

e) gases at exhaust valve outlet


M063.  Describe how you would time a fuel pump for a diesel engine.  Name the type of pump and describe how you would increase the fuel capacity in this pump


M064.  Consider an engine fitted with a chain driven camshaft.

a) what effect has the stretching of the chain upon engine performance and maintenance?

b) How is the chain tension adjusted to its initial value after stretching?

c) How is the engine timing corrected after adjustment of the chain?

d) What is the most common cause of failure and at what part of the chain does this usually occur?


M065.  Describe the purpose and operation of an over speed governor.



M066.  Compare load sensing and speed sensing governor. Why load sensing governor is employed with speed sensing governor.



M067.  How are the cylinder lubricators fitted in a large marine diesel engine that has a water jacket.  How is thermal expansion allowed for. Where is the location of the lubricator outlet in relation to the piston rings on the piston. Why is this position necessary?



M068.  Sketch and describe a wet liner for a four-stroke engine showing how it is sealed to allow for expansion.



M069.  Sketch and describe a cylinder liner from a large 2- stroke diesel engine which is water cooled.


M070.  Sketch and describe a cylinder liner for a heaby two stroke diesel engine.  What test is it given after construction and how is it fitted?  How is it sealed when fitted in the cylinder of an engine?


M071.  Describe the construction of a flywheel suitable for a 14" (355.60 mm) shaft.  How is it fitted?  What are the advantages of a flywheel?  Why could it be reduced in weight for some diesel engines?


M072.  Describe the construction of a cylinder including the head and liner.



M073.  A 4-stroke cylinder head has cracked.  Where would be the most likely place for the crack to occur? How would you inspect the head.  What repairs would you make and what precautions would you take to prevent reoccurrence?


M074.  Explain how cylinder liners and head covers develop crackd, stating possible causes.  What symptoms would indicate these cracks.


M075.  Some piston rings are made with an eccentric shape where the radial thickness is greatest diametrically opposite the gap.  Describe the manufacturing process of these eccentric piston rings. What advantages do these rings have over other types of piston rings?



M076.  What causes a shoulder to form in the ring grooves of pistons and how would you remedy the defect?


M077.  What might cause the piston of an internal combustion engine to overheat?  What steps are taken to return it to normal condition?


M078.  How would you know if a piston was in danger of seizing?  What would be the causes and the remedy?


M079.  Describe reversing system for a heavy fuel oil engine. How does it work.  Sketch the cams.



M080.  Describe a reverse system for a set of H.F.O. engines (slow speed)



M081.  Sketch and describe a jacket and piston cooling water system for a marine diesel engine.  How is expansion of the water allowed for?


M082.  Sketch and describe a water cooling system for a large engine.  Give cooling temperatures for piston and jacket water.  What are the disadvantages of sea water cooling?



M083.  Describe a system for piston cooling using oil as a medium.  State the advantages over fresh and salt water systems.  Why is it necessary to have the oil analyzed periodically?



M084.  Describe a lubricating oil system for a diesel engine.



M085.  Sketch and describe a lube oil system for a large diesel engine.



M080.  Sketch and describe the lubrication oil system of any diesel engine with which you are familiar.


M086.  Sketch and describe a diesel electric propulsion system for a ship and state how the propeller shafting is reversed.



M087.  Sketch and describe an air start system where the valves operate pneumatically.  What is meant by overlap?  How much overlap is required?



M088.  Describe with a simple sketch an air starting system. How is the overlap provided for, and why is it required? What is overlap?


M089.  Sketch and describe a flywheel that would be fitted to a large marine diesel engine.  Show in the sketches how it is fitted and secured.  What is the purpose of the flywheel? Recently some engine makers have considerably reduced the size of the flywheel.  Explain how this can be done.



M090.  Describe a de-tuner and explain it's purpose and operation.


M091.  Describe any type of hydraulic coupling, stating the type of fluid used in this coupling.


M092.  Describe an electro-magnetic coupling as used in reduction gearing from a diesel engine.  What is the advantage of reduction gearing?


M093.  Sketch and describe a multi-stage air compressor, naming all parts.  What possible dangerous conditions could occur?


M094.  Sketch and describe a 3-stage air compressor.  Why are intercoolers fitted?  What qualities are required by air compressor lubrication oils?  What dangers can arise from improper compressor lubrication?


M095.  Explain why it is necessary to have intercoolers on a multi-stage air compressor.  What attention do these require to keep them in a good and safe working condition?  Sketch and describe the construction of an intercooler suitable for a working pressure of 2400 kPa.  State the materials.


M096.  Explain isothermal, adiabatic and polytropic terms in a diesel engine air compressor.  What are the practical limitations?  M063.  How can an engine be started with air at a lower pressure than maximum compression pressure?


M097.  Discuss the causes of explosions in compressed air pipes, blast air lines, and crankcases.


M098.  Describe how bearing weardown and liner clearances are taken.


M099.  Describe the preparations necessary for the overhaul of a 400 horsepower four stroke, diesel engine.  What faults can you expect to find?


M100.  Describe the construction and principle of operation of a diesel engine silencer.



M101.  Explain clearance volume and swept volume referring to an engine cylinder.  What is compression ratio?  How would changes in clearance volume affect the engine?  Compare compression ratios for a gas and diesel engine.


M102.  What is the meaning of:

a) mechanical efficiency

b) overall efficiency

c) brake thermal efficiency

d) indicated efficiency

Give % for the above.



M103.  Sketch and explain how the brake power is received from a dynamometer and explain how the mechanical efficiency of the engine is determined.




M104.  Describe a shop trial on a heavy oil engine.  How are the indicated power and brake power determined?  How is the efficiency calculated?  What thermal efficiency would you expect?  What should be the approximate fuel consumption per brake power?


M105.  Discuss the advantages and disadvantages of using the following as cooling media:

a) fresh water

b) sea water

c) oil

State the effects should there reach a high temperature.



M106.  Describe a water tube boiler as fitted on a motor ship.  Name the fittings on the boiler and their purpose. Name the materials used in boiler.



M107.  Describe in detail the construction ao any vertical boiler used for auxiliary service aboard a notor ship.  Give details of all riveted joints with the aid of sketches


M108.  What are the probable causes of collapse of combustion chamber crowns in cylinder boilers at sea under full steaming conditions?  What defects would be looked for when the boiler is opened up for inspection?


M109.  Give an account of an examination of the combustion side of an auxiliary boiler.  State what defects are likely to be found and the corrective measures taken.


M110.  Describe how the following conditions are prevented in auxiliary boilers:

a) feed contamination by oil from heating coil drums

b) internal corrosion

c) furnace blow back

d) uptake fire.


M111.  You have joined a vessel as Chief Engineer.  Describe what inspection you would carry out on the auxiliary waste heat and oil fired boiler.  Mention faults you may expect to find and the possible cause of each defect.


M112.  Describe how you would prepare a Scotch Marine boiler for inspection and the possible defects you would look for.


M113.  Sketch an auxiliary boiler suitable for using with oil firing and exhaust heating.  Show clearly the mechanism for changing over the two methods of heating.  Discuss the

reasons for flue-gas explosions and how these occurrences may be prevented.


M114.  What is boiler grooving?  What causes it and how is it prevented?  Describe a repair required on a grooving defect.


M115. a) What governs the size of safety valves?

b) What is meant by accumulation of pressure

c) How is it contracted

d) What is satisfactory accumulation

e) What is the normal lift of the valve

M116.  Sketch and describe a high-lift safety valve.  State the advantages of this valve over a regular safety valve.

M117.  Describe the nature and purpose of the tests carried out on the feed and boiler water of an auxiliary boiler. State what type of boiler is considered and the source of "make up" feed.  Suggest causes for the fluctuations in the test results obtained.  Explain the effects of inadequate water treatment on the boiler.

M118.  What are the causes of burners being extinguished in oil fired boilers?

M119.  State the causes of furnace explosions.

Brought to you by www.dieselduck.net comments to [email protected]
Transport Canada has ask us to advise users of this webpage to keep in mind that these questions are not the exact questions found in their exams. Martin's Marine Engineering Page - www.dieselduck.net is not affiliated with Transport Canada and these questions have been gathered from various sources.