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.
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Disclaimer
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?
REF:DEC90
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?
REF:DEC88
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.
REF:MAR87 REF:MAY91
M011. Describe a rotary scavenge pump. How does reverse operation work?
REF:JUN88 REF:APR91
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?
REF:MAR83
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?
REF:JUL88
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?
REF:MAR87
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?
REF:MAY91
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.
REF:DEC90
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?
REF:DEC90
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?
REF:JAN87 REF:APR91
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.
REF:MAR87 REF:DEC88
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?
REF:MAR83 REF:JUN88
REF:JUL88 REF:NOV88
REF:DEC90
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?
REF:JUN88
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.
REF:JAN87 REF:JUN90
M058. Explain how the fuel pump and exhaust and inlet valves are
timed on a four stroke type engine.
REF:MAR83 REF:MAY91
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.
REF:APR91 REF:JUN91
M066. Compare load sensing and speed sensing governor. Why load
sensing governor is employed with speed sensing governor.
REF:DEC88
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?
REF:DEC88 REF:JUN91
M068. Sketch and describe a wet liner for a four-stroke engine
showing how it is sealed to allow for expansion.
REF:MAR83
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.
REF:JUN83
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?
REF:DEC88 REF:JUN91
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.
REF:MAR87
M080. Describe a reverse system for a set of H.F.O. engines (slow
speed)
REF:JUN88
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?
REF:MAR83 REF:APR91
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?
REF:JUN83
M084. Describe a lubricating oil system for a diesel engine.
REF:MAR83
M085. Sketch and describe a lube oil system for a large diesel
engine.
REF:JUN88
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?
REF:DEC88
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.
REF:DEC88
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.
REF:MAR83
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.
REF:MAR83
M103. Sketch and explain how the brake power is received from a
dynamometer and explain how the mechanical efficiency of the engine is
determined.
REF:MAR83 REF:JUL88
REF:FEB91
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.
REF:DEC90
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.
REF:APR91
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.