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HK Engine Operator Grade 2 study materials
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HK Engine Operator Grade 2 practice questions

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Question 1Marine engine operation and watchkeeping

During a manned engine room watch, at what interval must the engineer on watch normally record the main engine and auxiliary readings in the engine room log?

  1. Only when an alarm is activated
  2. At the end of each watch only
  3. Every hour unless the Chief Engineer directs otherwise Correct answer.
  4. Every four hours

Explanation

Standard watchkeeping practice requires hourly recording of parameters such as exhaust temperatures, pressures, and fuel/lube oil levels so trends can be detected early and compared with previous readings. Longer intervals or event-driven recording would allow developing faults to go unnoticed between entries.

Question 2Marine engine operation and watchkeeping

Which document must the relieving engineer read and countersign before taking over the engine room watch?

  1. The muster list
  2. The ship's articles of agreement
  3. The cargo stowage plan
  4. The engine room log book and standing orders Correct answer.

Explanation

A proper handover requires the relieving officer to read the log book, standing orders, and any night orders, then countersign to confirm acceptance of the watch. This ensures continuity of information about running machinery, defects, and pending work.

Question 3Marine engine operation and watchkeeping

An engineer on watch notices the main engine fuel oil viscosity at the injector pumps has dropped below the specified range. Which immediate action protects the engine?

  1. Reduce the fuel oil heater outlet temperature Correct answer.
  2. Stop the fuel booster pump
  3. Open the fuel oil settling tank drain
  4. Increase the fuel oil heater outlet temperature

Explanation

Viscosity falls when fuel is overheated, so the heater outlet temperature must be reduced to restore the correct viscosity at the injector pumps. Correct viscosity ensures proper atomisation and combustion; excessively hot fuel causes poor spray patterns and possible pump wear.

Question 4Marine engine operation and watchkeeping

What is the purpose of the scavenge air receiver drain on a two-stroke diesel engine?

  1. To remove accumulated oil and water carried over from the turbocharger and air cooler Correct answer.
  2. To supply starting air to the cylinders
  3. To drain cooling water from the cylinder jackets
  4. To release excess scavenge air pressure to atmosphere

Explanation

Moisture and lube oil carried over from the turbocharger and air cooler collect in the scavenge air receiver, and the drain removes this so it is not drawn into the cylinders. Water ingress can cause liner corrosion and poor combustion, while excess oil can lead to scavenge space fires.

Question 5Marine engine operation and watchkeeping

During an unattended machinery space period, the dead man alarm system is activated and not acknowledged within the set delay. What is the designed response?

  1. The bilge pump starts automatically
  2. The generator is automatically started and the main engine is slowed
  3. The main engine continues running and an alarm sounds locally only
  4. The main engine is automatically stopped and the engineer alarm is raised Correct answer.

Explanation

The dead man alarm protects the unattended engine room by first warning the duty engineer, then, if unacknowledged, initiating an automatic slowdown or stop of the main engine and raising an alarm in the accommodation. This prevents the vessel running blind with no engineer available.

Question 6Marine engine operation and watchkeeping

The main engine exhaust gas temperature on one unit rises significantly above the others at constant load. Which fault is most consistent with this reading?

  1. Low cooling water temperature on all units
  2. A leaking exhaust valve or defective fuel injector on that unit Correct answer.
  3. A worn main bearing on the crankshaft
  4. A blocked scavenge air cooler on the whole engine

Explanation

A single unit running hot at constant load usually indicates a combustion fault on that cylinder, such as a leaking exhaust valve, faulty injector, or poor compression. Comparing units isolates the fault, whereas system-wide faults would affect all cylinders.

Question 7Marine engine operation and watchkeeping

Before starting a main engine on starting air, which condition must be confirmed regarding the turning gear?

  1. The turning gear is disengaged and the interlock permits starting Correct answer.
  2. The turning gear motor is running
  3. The turning gear is engaged and the indicator is lit
  4. The turning gear is removed from the engine

Explanation

The turning gear must be fully disengaged, and the interlock must confirm this, before starting air can be admitted; otherwise the engine could turn against the engaged gear and cause severe damage. Most installations have an interlock that blocks starting air while the gear is engaged.

Question 8Marine engine operation and watchkeeping

What is the primary function of the cylinder lubricator on a large slow-speed two-stroke diesel engine?

  1. To lubricate the turbocharger bearings
  2. To deliver metered oil to the cylinder liner walls for boundary lubrication Correct answer.
  3. To supply oil to the crankshaft bearings
  4. To cool the piston crown

Explanation

Cylinder lubricators deliver small, precisely metered quantities of alkaline cylinder oil to the liner surface to neutralise combustion acids and provide boundary lubrication between rings and liner. This function is separate from the system oil that serves the bearings and is not a cooling function.

Question 9Marine engine operation and watchkeeping

A watchkeeper observes that the main engine fuel oil pressure at the injection pumps is fluctuating and lower than normal. Which check should be made first?

  1. The sea water cooling pump suction strainer
  2. The bilge water separator alarm history
  3. The fuel oil service pump discharge pressure and filters for blockage Correct answer.
  4. The starting air compressor unloading valve

Explanation

Fluctuating or low fuel pressure at the injection pumps most directly points to the fuel supply side, so the service pump discharge pressure and filter differential should be checked for blockage or pump fault. This follows the principle of tracing a symptom back along its immediate supply path.

Question 10Marine engine operation and watchkeeping

Why must the main engine be warmed through before being run up to full load after a cold start?

  1. To allow the fuel oil to reach the correct temperature only
  2. To allow the turning gear to be engaged
  3. To avoid thermal shock and uneven expansion of liners, pistons, and turbocharger components Correct answer.
  4. To discharge all starting air from the receivers

Explanation

Gradual warming allows uniform thermal expansion of liners, pistons, and turbocharger parts and lets lubricating oil reach working temperature, preventing thermal stress, seizure, and excessive wear. Sudden loading of cold machinery can cause cracking and scuffing.

Question 11Marine engine operation and watchkeeping

During manoeuvring, the bridge orders a repeated series of engine movements. How should the engineer respond to each telegraph order?

  1. Execute only after the Chief Engineer approves each order
  2. Acknowledge and execute immediately, then record the order and time in the manoeuvring record Correct answer.
  3. Wait for written confirmation before executing
  4. Record the order but delay execution until the next watch

Explanation

Manoeuvring orders must be executed promptly and acknowledged, with each order and its time logged in the manoeuvring record book for later verification. Delays during manoeuvring endanger the vessel, and the record provides an auditable trail of engine movements.

Question 12Marine engine operation and watchkeeping

What is the correct action if the main engine lubricating oil pressure falls to the low alarm set point while the engine is running?

  1. Reduce speed/load and investigate, and prepare for automatic slowdown or stop if pressure continues to fall Correct answer.
  2. Increase engine load to raise oil pressure
  3. Ignore the alarm if bearing temperatures are normal
  4. Stop the lubricating oil pump to reset the alarm

Explanation

Falling lube oil pressure threatens bearing integrity, so load should be reduced and the cause investigated while the automatic slowdown or trip protects the engine if pressure falls further. Continuing at load risks bearing damage and crankcase explosion.

Question 13Marine engine operation and watchkeeping

Which reading best indicates that a turbocharger is fouled on the gas side?

  1. Falling exhaust gas temperature before the turbine
  2. Increasing jacket cooling water outlet temperature
  3. Rising exhaust gas temperature after the turbine at constant load with reduced scavenge air pressure Correct answer.
  4. Rising fuel oil viscosity

Explanation

Gas-side fouling reduces turbine efficiency, so scavenge air pressure falls and exhaust temperature after the turbine rises at constant load. This combination is the classic signature of turbine nozzle or blade fouling and indicates the need for water washing or cleaning.

Question 14Marine engine operation and watchkeeping

During a crankcase inspection, an oil mist detector alarm activates. What is the correct immediate response?

  1. Open the crankcase doors to ventilate the space
  2. Reduce engine speed/stop the engine as per procedure and do not open crankcase doors until conditions are safe Correct answer.
  3. Increase crankcase ventilation fan speed only
  4. Continue running and monitor the detector reading

Explanation

An oil mist alarm indicates possible incipient crankcase explosion, so the engine must be slowed or stopped and the crankcase allowed to cool before any door is opened. Opening doors while hot can admit air and create an explosive mixture, so entry is prohibited until safe.

Question 15Marine engine operation and watchkeeping

What is the main purpose of the jacket cooling water header tank on a diesel engine installation?

  1. To supply cooling water to the fuel injectors
  2. To act as a reservoir for starting air
  3. To store distilled water for boiler feed only
  4. To provide a static head, allow expansion, and vent air from the cooling system Correct answer.

Explanation

The header tank provides a static head on the cooling water pump suction, accommodates thermal expansion of the coolant, and allows air and vapour to escape from the system. Maintaining the correct level and venting are essential to prevent cavitation and hot spots.

Question 16Marine engine operation and watchkeeping

The fuel oil purifier is observed discharging dirty oil continuously to the sludge outlet instead of clean oil to the service tank. Which cause is most likely?

  1. The main engine load has been reduced
  2. The fuel oil service pump is running too fast
  3. The starting air pressure is low
  4. The purifier bowl is incorrectly assembled or the gravity disc is the wrong size Correct answer.

Explanation

Continuous dirty discharge usually indicates incorrect bowl assembly or a gravity disc size that places the interface badly, so oil is lost with the water phase. Correct assembly and the proper gravity disc for the fuel density restore separation.

Question 17Marine engine operation and watchkeeping

What does a rising differential pressure across the main engine lubricating oil filters indicate?

  1. The oil pump is delivering excess flow
  2. The oil cooler is bypassing
  3. The oil viscosity has fallen below specification
  4. The filters are becoming blocked and need cleaning or changeover Correct answer.

Explanation

A rising differential pressure across a filter shows increasing resistance to flow as contaminants accumulate, so the filter should be changed over or cleaned before bypass occurs. If left, the bypass valve may open and allow unfiltered oil to reach the bearings.

Question 18Marine engine operation and watchkeeping

During a blackout, the emergency generator fails to start automatically. Which action should the engineer on watch take first?

  1. Start the main engine immediately
  2. Wait for the bridge to restore power
  3. Attempt to restart the emergency generator manually and check its starting system Correct answer.
  4. Open all circuit breakers on the main switchboard

Explanation

The priority is to restore essential power, so the engineer should investigate and manually start the emergency generator, checking its starting air or battery system. Emergency lighting, steering, and navigation equipment depend on this supply, so delay is hazardous.

Question 19Marine engine operation and watchkeeping

What is the function of the air cooler condensate drain in the scavenge air system?

  1. To drain fuel from the scavenge space
  2. To release starting air after manoeuvring
  3. To supply cooling water to the air cooler
  4. To remove condensed water from the air cooler so it does not enter the scavenge receiver and cylinders Correct answer.

Explanation

Cooling the charge air condenses moisture, which must be drained so it does not enter the scavenge receiver and cylinders where it can cause corrosion and poor combustion. Keeping the drain clear is part of routine watchkeeping.

Question 20Marine engine operation and watchkeeping

The main engine is running at full sea load when the piston cooling oil outlet temperature on one unit rises above normal. Which interpretation is most reasonable?

  1. The starting air receiver pressure is low
  2. The fuel oil viscosity is too high
  3. The piston cooling oil flow to that unit is restricted or the cooling space is fouled Correct answer.
  4. The turbocharger is over-speeding

Explanation

An isolated rise in piston cooling oil outlet temperature points to reduced cooling oil flow or fouled cooling passages on that piston, which risks overheating and cracking of the crown. The unit should be investigated and load adjusted as required.

Question 21Marine engine operation and watchkeeping

Why is it important to keep the starting air receivers drained of condensate regularly?

  1. To increase starting air capacity
  2. To improve fuel atomisation
  3. To prevent water carry-over into the air starting system and valves, which can cause corrosion and malfunction Correct answer.
  4. To reduce the air compressor discharge temperature

Explanation

Condensate accumulating in air receivers can be carried into starting air lines and valves, causing corrosion, sticking, and failure to start the engine when needed. Regular draining keeps the starting air supply dry and reliable.

Question 22Marine engine operation and watchkeeping

During a long ocean passage, the watchkeeper notices the main engine fuel consumption has gradually increased at constant speed and load. Which investigation is most appropriate?

  1. Check exhaust temperatures, scavenge air pressure, and turbocharger condition for fouling or injection faults Correct answer.
  2. Check the emergency fire pump suction
  3. Check the accommodation air conditioning settings
  4. Check the ship's ballast water treatment log

Explanation

A gradual rise in fuel consumption at constant output suggests deteriorating combustion or air supply efficiency, so exhaust temperatures, scavenge pressure, and turbocharger condition should be compared with baseline readings. This trend analysis identifies fouling or injector faults early.

Question 23Marine engine operation and watchkeeping

What is the purpose of the engine room watch alarm system when machinery spaces are periodically unattended?

  1. To control the purifier discharge cycle
  2. To automatically start the main engine
  3. To alert the duty engineer in the accommodation if an alarm occurs and cannot be handled locally Correct answer.
  4. To record fuel consumption for the charterer

Explanation

The watch alarm extends alarms from the engine room to the duty engineer's cabin so that faults are brought to their attention when the space is unattended. If not acknowledged within the set time, the system escalates to other engineers and may initiate slowdown.

Question 24Marine engine operation and watchkeeping

Which action is correct before opening up a main engine cylinder for inspection after a suspected exhaust valve leak?

  1. Ensure the engine cannot be started, isolate starting air, and allow the unit to cool Correct answer.
  2. Increase cylinder lubricator output to maximum
  3. Open the indicator cock and start the engine briefly
  4. Leave the turning gear engaged and running

Explanation

Safe isolation requires that starting air be shut off and the engine secured so it cannot be turned, and the unit must be allowed to cool before opening. This prevents inadvertent starting and burns from hot components during maintenance.

Question 25Marine engine operation and watchkeeping

The main engine fails to start on air although the starting air pressure is normal. Which cause is most likely?

  1. The jacket water header tank is full
  2. The sea water cooling pump is running
  3. The fuel oil service tank level is high
  4. The starting air distributor timing is incorrect or the pilot air valve is faulty Correct answer.

Explanation

With normal air pressure, failure to turn usually lies in the control path: incorrect distributor timing, a faulty pilot air valve, or a blocked starting valve. The air supply itself is confirmed good, so the fault is in distribution or actuation.

Question 26Marine engine operation and watchkeeping

Under the engine room watchkeeping arrangements for a periodically unattended machinery space, what must happen before the space is left unattended?

  1. The engineer on watch must obtain verbal permission from the bridge at each departure.
  2. The chief engineer must personally remain in the engine room at all times.
  3. Only the main engine governor needs to be tested and confirmed working.
  4. The responsible engineer must ensure all alarms and automatic changeover devices are proven operational and the space is checked. Correct answer.

Explanation

Before a periodically unattended machinery space is left, the responsible engineer must confirm that alarms, safeguards and automatic changeover arrangements are functioning, and carry out a final round of the space. This ensures any developing fault will be detected and the machinery protected without an engineer present. Verbal permission from the bridge each time is not the requirement.

Question 27Marine engine operation and watchkeeping

While the main engine is running at sea load, the watchkeeper notices the scavenge air pressure has dropped and the exhaust gas temperature after each unit has risen. Which fault best fits this pattern?

  1. A turbocharger air-side restriction such as a fouled compressor. Correct answer.
  2. Low fuel oil viscosity at the injection pumps.
  3. A partially blocked scavenge air cooler or its water side.
  4. A leaking cylinder starting air valve held slightly open.

Explanation

A restriction on the compressor side of the turbocharger reduces the air delivered to the scavenge space, so scavenge pressure falls and combustion becomes less complete, raising exhaust temperatures. A blocked air cooler would also raise temperatures but normally shows a rise in air cooler differential pressure and a higher air temperature rather than a pure scavenge pressure drop. The pattern of both low scavenge pressure and high exhaust temperature points to reduced turbocharger air output.

Question 28Marine engine operation and watchkeeping

What is the correct procedure for the engineer on watch when the bridge rings 'finished with engines' on the engine room telegraph?

  1. Stop the engine immediately and leave the engine room without further checks.
  2. Keep the engine running until the chief engineer arrives to authorise the stop.
  3. Stop the engine, confirm the telegraph reply, and complete the shutdown checks and log entries. Correct answer.
  4. Acknowledge the order but leave the engine running at manoeuvring speed.

Explanation

'Finished with engines' is the final order of a manoeuvring sequence, so the watchkeeper stops the engine, returns the correct reply on the telegraph, and then carries out the post-shutdown checks such as confirming the turning gear status and recording the event. Acknowledging the order is not optional and the engine must not be left running.

Question 29Marine engine operation and watchkeeping

During a sea passage, the main engine lubricating oil sump level slowly falls while no external leakage is visible. Which cause should the watchkeeper investigate first?

  1. The lubricating oil cooler is leaking sea water into the oil.
  2. A piston cooling oil return is leaking into the crankcase.
  3. A cylinder liner or piston cooling component is allowing oil to enter the scavenge space. Correct answer.
  4. The fuel oil booster pump is drawing oil from the wrong tank.

Explanation

A slow, steady loss of sump oil with no visible external leak commonly means oil is being burned or carried over into the scavenge space, often through a cracked piston cooling pipe or a leaking liner component. The watchkeeper should check scavenge drain inspection and the exhaust for oil carryover. Sea water ingress would raise the level and contaminate the oil rather than lower it.

Question 30Marine engine operation and watchkeeping

Which precaution is essential before any person enters the crankcase of a main engine that has just been stopped?

  1. The crankcase doors are left open to improve ventilation before entry.
  2. The starting air is isolated, the indicator cocks are open and the turning gear is engaged and locked. Correct answer.
  3. The fuel oil booster pump is kept running to maintain circulation.
  4. The engine is warmed through to normal operating temperature.

Explanation

Before crankcase entry, starting air must be isolated and the indicator cocks opened so the engine cannot be turned on air, and the turning gear must be engaged and locked to prevent rotation. These measures protect against the engine being started or turned while a person is inside. Warming the engine or running the fuel pump would create hazards rather than remove them.

Question 31Marine engine operation and watchkeeping

The watchkeeper observes that the main engine fuel oil viscosity at the injection pumps has fallen below the specified range while the engine runs at constant load. What is the most likely effect on combustion?

  1. Injection will be advanced and the engine will run smoother.
  2. Injection will be retarded and combustion will be poor, with possible knocking and higher exhaust temperature. Correct answer.
  3. Combustion will be delayed and exhaust temperature will fall.
  4. Fuel consumption will fall because thinner fuel atomises more easily.

Explanation

Fuel viscosity controls atomisation and the effective injection timing. Too low a viscosity causes the fuel to leak past the pump plunger, retarding injection, and gives poor atomisation, leading to rough combustion, possible knocking and higher exhaust temperatures. The viscosity must be held within the maker's range by adjusting the fuel heater.

Question 32Marine engine operation and watchkeeping

Why must the main engine starting air receivers be charged to the specified pressure before manoeuvring begins?

  1. Because the engine must have sufficient air for the required number of consecutive starts and manoeuvres. Correct answer.
  2. Because the air pressure sets the fuel injection timing.
  3. Because the receiver pressure controls the governor speed setting.
  4. Because the air is used to cool the exhaust valves during low-load running.

Explanation

The starting air receivers must hold enough air at the correct pressure to provide the number of consecutive starts required by classification rules and to support a full manoeuvring sequence. Insufficient air could leave the engine unable to start when the bridge needs it, which is a serious hazard in confined waters. The air does not cool exhaust valves or set injection timing.

Question 33Marine engine operation and watchkeeping

During a manoeuvring sequence the telegraph is answered but the engine does not respond to the command. What is the first action the engineer on watch should take?

  1. Immediately report to the bridge that the engine has failed and await instructions.
  2. Increase starting air pressure and try again without checking anything.
  3. Change over to the emergency steering position and continue manoeuvring.
  4. Check the local control position and the fuel and starting air supplies before reporting. Correct answer.

Explanation

When the engine does not respond, the watchkeeper should quickly check the obvious causes such as whether the local/remote control selector is in the correct position and whether fuel and starting air supplies are available. Only after this rapid check should the bridge be informed, so the report is useful. Blindly increasing pressure or leaving the controls is not a safe response.

Question 34Marine engine operation and watchkeeping

What is the purpose of the engine room dead-man alarm when the machinery space is unattended?

  1. To alert the crew when the bilge high-level switch operates.
  2. To sound an alarm if the duty engineer does not respond within a set period. Correct answer.
  3. To detect a drop in fuel oil pressure at the injection pumps.
  4. To warn the bridge when the main engine speed exceeds the set limit.

Explanation

The dead-man alarm requires the duty engineer to acknowledge it at set intervals; if there is no response within the time limit, an alarm is raised in the accommodation and on the bridge. This protects the ship if the engineer becomes incapacitated while the space is unattended. It does not monitor engine speed, fuel pressure or bilge levels.

Question 35Marine engine operation and watchkeeping

The watchkeeper finds that the main engine jacket cooling water outlet temperature is rising steadily while the inlet temperature and flow remain normal. Which cause is most likely?

  1. The jacket water cooler is fouled on the sea water side.
  2. The engine load has increased and the heat load on the jackets has risen. Correct answer.
  3. The expansion tank is overfilled.
  4. The sea water cooling pump has stopped.

Explanation

If inlet temperature and flow are unchanged but outlet temperature rises, the engine is rejecting more heat, which happens when load increases. The watchkeeper should confirm the load and check that the temperature stabilises within limits. A fouled cooler or stopped sea water pump would show a rise in inlet temperature or reduced cooling, not a normal inlet with a rising outlet.

Question 36Marine engine operation and watchkeeping

Which of the following is the correct action for the engineer on watch when the main engine low lubricating oil pressure alarm sounds but the engine is still running?

  1. Reduce speed to idle and continue watching until the next round.
  2. Stop the engine immediately without checking anything.
  3. Silence the alarm and log it as a spurious signal.
  4. Acknowledge the alarm, check the pressure gauge and pump condition, and be ready to stop the engine if pressure does not recover. Correct answer.

Explanation

On a low lubricating oil pressure alarm the watchkeeper acknowledges it, verifies the actual pressure at the gauge, checks the pump and filters, and takes action to restore pressure. If the pressure continues to fall towards the low-low trip point, the engine must be stopped to prevent bearing damage. Silencing and ignoring the alarm or continuing at load is unsafe.

Question 37Marine engine operation and watchkeeping

What does a steadily increasing differential pressure across the main engine fuel oil filters indicate?

  1. The fuel oil heater is over-performing.
  2. The fuel oil booster pump is delivering too much pressure.
  3. The filters are becoming blocked and require cleaning or changeover. Correct answer.
  4. The fuel oil viscosity is too low.

Explanation

Differential pressure across a filter rises as trapped dirt reduces the open area, so an increasing differential means the element is loading up. The watchkeeper should change over to the standby filter and clean the blocked one before the differential reaches the alarm limit. Viscosity, pump output and heater performance do not directly cause a rising filter differential.

Question 38Marine engine operation and watchkeeping

During a blackout, the emergency generator starts but the emergency switchboard does not energise. Which check should the engineer make first?

  1. The fuel oil purifier operating temperature.
  2. The emergency generator circuit breaker position and the emergency switchboard changeover. Correct answer.
  3. The jacket water expansion tank level.
  4. The main engine starting air pressure.

Explanation

If the emergency generator runs but the emergency switchboard stays dead, the likely cause is that the generator circuit breaker has not closed or the changeover to emergency supply has not operated. The engineer should check the breaker and the automatic changeover before looking elsewhere. The other items are unrelated to emergency power distribution.

Question 39Marine engine operation and watchkeeping

What is the correct response when the main engine crankcase oil mist detector gives a slow, rising reading rather than an instant alarm?

  1. Investigate the trend, check bearing temperatures and be prepared to stop the engine if the reading continues to rise. Correct answer.
  2. Stop the engine immediately and open the crankcase doors.
  3. Ignore it because only the instant alarm requires action.
  4. Increase the detector sensitivity and continue running.

Explanation

A slow rise in oil mist concentration may indicate a developing hot spot or bearing distress. The watchkeeper should investigate the trend, check bearing temperatures and other indicators, and be ready to stop the engine if the reading continues upward. Only a rapid alarm calls for immediate shutdown; opening crankcase doors while hot is dangerous.

Question 40Marine engine operation and watchkeeping

Which document should the engineer on watch consult to confirm the correct warm-up procedure and load limits for the main engine after a long repair?

  1. The engine room log book from the previous voyage.
  2. The bridge night order book.
  3. The cargo loading plan.
  4. The manufacturer's instruction book and the ship's planned maintenance records. Correct answer.

Explanation

Warm-up procedures and load limits after repair are specified by the engine manufacturer's instruction book and reflected in the ship's maintenance records. The watchkeeper must follow those documented limits to avoid thermal stress. The log book, night orders and cargo plan do not define engine operating limits.

Question 41Marine engine operation and watchkeeping

The watchkeeper observes that the main engine exhaust gas temperature after the turbocharger has dropped while the speed and load remain constant. Which cause should be considered?

  1. The turbocharger turbine is fouled on the gas side. Correct answer.
  2. The scavenge air temperature has fallen.
  3. The fuel oil viscosity has increased.
  4. The cylinder lubricator feed rate has been increased.

Explanation

A fouled turbine reduces the energy extracted from the exhaust gas, so the temperature after the turbocharger falls while the engine load is unchanged. The watchkeeper should check turbocharger speed and the pressure drop across the turbine. Fuel viscosity, scavenge air temperature and cylinder lubrication affect combustion but not the post-turbine temperature in this way.

Question 42Marine engine operation and watchkeeping

What is the main purpose of the turning gear interlock on a main engine?

  1. To measure the engine speed for the governor.
  2. To prevent the engine from being started on air while the turning gear is engaged. Correct answer.
  3. To drain condensate from the starting air system.
  4. To lock the crankshaft during normal running.

Explanation

The turning gear interlock prevents the starting air from being admitted while the turning gear is still engaged, which would otherwise damage the turning gear and the engine. The interlock is a safety device that must be proven during maintenance. It does not lock the shaft during running or measure speed.

Question 43Marine engine operation and watchkeeping

During a long sea passage the watchkeeper notices the main engine fuel oil consumption has risen gradually at constant speed and load, with a slight rise in exhaust temperature. Which explanation is most consistent?

  1. The hull is fouling, so the propeller requires more power for the same speed. Correct answer.
  2. The fuel oil flow meter has drifted and the readings are false.
  3. The cylinder lubricator is over-supplied.
  4. The starting air compressor is running more often.

Explanation

If the ship's speed and engine load are held constant but fuel consumption and exhaust temperature creep up, the propeller is demanding more power, which commonly results from hull and propeller fouling. The watchkeeper should record the trend and report it for performance monitoring. A drifting meter would not raise exhaust temperature, and the other items do not explain the trend.

Question 44Marine engine operation and watchkeeping

Which action is required before opening up a main engine cylinder for inspection after a suspected exhaust valve leak?

  1. Run the engine at full load to confirm the leak.
  2. Drain the jacket water system completely and leave it open.
  3. Isolate the starting air, engage and lock the turning gear, and allow the unit to cool. Correct answer.
  4. Remove the cylinder head while the engine is still hot.

Explanation

Before opening a cylinder, the starting air must be isolated, the turning gear engaged and locked, and the unit allowed to cool to avoid burns and thermal distortion. These steps protect personnel and the component. Running at full load would worsen the leak, and removing a head while hot is dangerous.

Question 45Marine engine operation and watchkeeping

What is the function of the scavenge air receiver drain in a large two-stroke engine?

  1. To remove condensed water and oil carried over from the air cooler and cylinders. Correct answer.
  2. To provide cooling water to the air cooler.
  3. To supply additional air to the turbocharger.
  4. To regulate the scavenge air pressure.

Explanation

The scavenge air receiver drain removes condensate and carried-over oil that collect in the scavenge space, preventing water carryover into the cylinders and reducing fire risk. It must be checked and drained regularly on watch. It does not supply air, regulate pressure or carry cooling water.

Question 46Marine engine operation and watchkeeping

The main engine governor has been set to constant speed but the engine speed fluctuates slightly with each revolution. Which cause is most likely?

  1. One fuel injection pump is delivering an uneven quantity. Correct answer.
  2. The governor oil level is too high.
  3. The starting air receiver pressure is low.
  4. The jacket water temperature is low.

Explanation

Cyclic speed fluctuation at constant governor setting usually points to one unit delivering uneven power, often from an injection pump fault or a sticking fuel valve. The watchkeeper should compare exhaust temperatures and indicator diagrams across units. Governor oil level, starting air and jacket temperature do not produce per-revolution fluctuation.

Question 47Marine engine operation and watchkeeping

What should the engineer on watch do if the main engine cannot be started on air even though the starting air pressure at the receiver is normal?

  1. Check the starting air valve operation and the control air supply to the starting system. Correct answer.
  2. Open the indicator cocks and turn the engine by hand.
  3. Increase the fuel oil rack setting and try again.
  4. Reduce the starting air pressure to avoid over-speeding.

Explanation

With normal receiver pressure but no start, the fault lies between the receiver and the cylinders, such as a stuck starting air valve, a blocked pilot air line or a control air failure. The watchkeeper should check the valve operation and control air supply. Increasing fuel or reducing pressure does not address the cause.

Question 48Marine engine operation and watchkeeping

Why is it important to record main engine operating parameters in the engine room log at regular intervals during a sea watch?

  1. To calculate the crew's overtime hours.
  2. To provide a trend record that allows faults to be detected early and performance to be assessed. Correct answer.
  3. To satisfy the classification society's annual survey only.
  4. To replace the need for alarm systems.

Explanation

Regular logging builds a trend record of temperatures, pressures and consumption, so gradual changes such as fouling or wear can be spotted before they become failures. It also supports performance assessment and maintenance planning. It does not replace alarms nor serve only for surveys.

Question 49Marine engine operation and watchkeeping

During manoeuvring, the bridge orders a series of rapid engine movements. What is the correct watchkeeping practice for the engineer?

  1. Leave the engine room controls on automatic and attend to other machinery.
  2. Increase the fuel rack limit to speed up the response.
  3. Delay each movement until the engine has stabilised at the previous setting.
  4. Carry out each order promptly, confirm the reply on the telegraph, and monitor starting air, fuel and cooling parameters closely. Correct answer.

Explanation

During manoeuvring the engineer must execute each telegraph order promptly and confirm the reply, while closely watching starting air consumption, fuel pressure and cooling temperatures because of the rapid load changes. Delaying orders or leaving the controls unattended risks a manoeuvring casualty. The fuel rack limit must not be altered to force a faster response.

Question 50Marine engine operation and watchkeeping

The main engine is running at sea load when the cylinder cooling water outlet temperature on one unit rises sharply while the others remain normal. Which cause should be investigated first?

  1. The main sea water cooling pump has stopped.
  2. A cylinder liner cooling passage or the unit's outlet valve is restricted. Correct answer.
  3. The jacket water system pressure is too high.
  4. The expansion tank is empty.

Explanation

A sharp rise on a single unit while the others stay normal points to a local restriction in that unit's cooling passage or outlet valve, reducing flow through that cylinder. The watchkeeper should reduce load if necessary and investigate that unit. A stopped sea water pump or empty expansion tank would affect all units, not one.