WorksheetsMCQ Assessment: Gas Turbine Propulsion
Total questions: 60
Worksheet time: 30mins
What cycle does a marine gas turbine operate on?
Otto cycle
Brayton cycle
Diesel cycle
Rankine cycle
Which component mixes fuel with compressed air for ignition?
Combustion chamber
Compressor
Turbine
Reduction gearbox
What is the primary purpose of the lubrication system?
Compress air for combustion
Transmit power to the propeller
Detect fire in the turbine room
Maintain bearing and component temperatures
Which system directs air to the compressor while filtering contaminants?
Fuel system
Air intake and filtration system
Control system
Cooling system
What is the first step in safe turbine startup?
Engage starter
Introduce fuel
Power-up control systems
Purge combustion chamber
What must be checked for proper startup regarding fuel?
Viscosity, purity, and cetane number
Only temperature
Which turbine type extracts energy from combustion gases?
Low-pressure turbine
High-pressure turbine
Both A and B
None of the above
What does EGT stand for?
Engine Gas Temperature
Exhaust Gas Temperature
Electric Generator Test
Engine Gear Transmission
Which safety precaution is mandatory before operating the turbine?
Post warning signs and restrict access
Reduce cooling water flow
Block intake ducts
Disable alarms
Which system ensures sensor calibration and interlock engagement?
Fuel system
Exhaust system
Lubrication system
Control and monitoring system
Why is pre-lubrication performed before turbine startup?
To circulate oil and protect bearings
To ignite the fuel-air mixture
To measure exhaust temperature
To power the reduction gearbox
What is the main purpose of purging the combustion chamber?
Increase fuel pressure
Remove residual fuel vapors
Warm up turbine blades
Why should air intake and exhaust passages be free from obstructions?
To prevent oil leaks
To ensure proper combustion and turbine efficiency
To reduce vibration in the gearbox
To cool the control system
Why must maintenance logs be reviewed before startup?
To determine fuel, lubricating oil and water consumptions
To calibrate sensors automatically and ensure safe operation
To calculate turbine efficiency considering all recorded parameters
To ensure previous issues are resolved and safe operation
What is the reason for gradual fuel introduction during startup?
To prevent overtemperature and hot start
To increase lubrication oil flow
To speed up turbine rotation
To test emergency stop systems
Why are temperature and pressure limits monitored during operation?
To ensure turbine efficiency and prevent damage
To measure ambient air quality
To test exhaust system capacity
To maintain gearbox alignment
How does the reduction gearbox contribute to propulsion?
Generates electricity
Transmits turbine output to the propeller
Increases fuel pressure
Controls exhaust temperature
Why is FOD (Foreign Object Debris) clearance important?
Prevents oil contamination
Prevents compressor and turbine damage
Ensures proper lubrication
Calibrates sensors
Why should emergency shutdown procedures be reviewed with the engineering team?
To increase fuel efficiency
To adjust gearbox alignment after a period of time not in use
To speed up startup sequence
To ensure safe response to abnormal conditions
What is the purpose of the control and monitoring system?
Automates startup and regulates turbine performance
Delivers fuel to combustion chamber
Extracts energy from exhaust gases
Directs cooling water flow
If a turbine fails to achieve light-off, which system should be inspected first?
Cooling water system
Lubrication system
Fuel delivery and ignition system
Air intake filter
During startup, exhaust gas temperature rises rapidly. What should the operator do?
Immediately abort start to prevent overtemperature
Introduce more fuel
Ignore until self-sustaining speed
Stop lubrication pumps
A foreign object is detected in the intake duct. What is the correct procedure?
Remove obstruction before starting
Start turbine at low power
Increase air intake speed to dislodge it
Purge fuel system immediately
How should an engineer verify pre-lubrication effectiveness?
Activate control panel alarms
Check exhaust gas temperature
Inspect combustion chamber
Measure oil pressure and flow
A vibration sensor indicates misalignment during startup. What is the best response?
Continue startup cautiously
Shut down turbine and inspect shaft alignment
Increase cooling flow
Adjust fuel flow
How can air quality and temperature affect turbine performance?
Poor quality reduces combustion efficiency
High quality prevents bearing damage
Temperature only affects lubrication
Air quality affects gearbox lubrication
If emergency stop is tested during pre-start, what should be checked?
Fuel valve pressure
Starter disengagement and turbine halt
Bearing oil temperature
Control panel calibration
A fuel filter is partially clogged. How should this be handled?
Clean or replace filter before startup
Increase fuel pressure to compensate
How does aligning the propeller shaft with the gearbox affect operation?
Enhances fuel flow
Increases exhaust temperature
Prevents abnormal vibration and mechanical damage
Adjusts control system sensors
During low-power warm-up, why is monitoring TIT important?
To ensure thermal stability and avoid overheating
To check fuel pressure
To purge the combustion chamber
To calibrate vibration sensors
After startup, EGT is higher than normal while RPM is stable. Which component is likely responsible?
Lubrication oil high viscosity
Dirty air intake filter
Fuel system delivering excess fuel
Insufficient cooling water flow
If oil pressure drops while turbine is running, what could be the root cause?
Foreign object in intake
Misaligned shaft
Excess fuel
Pump malfunction or leak
An engineer observes vibration after light-off. How can the problem be diagnosed?
Verify fuel cetane number to confirm performance
Check for FOD, misalignment, or structural damage
Purge the combustion chamber and check fuel filter
Hot start occurs frequently. Which operational factor is most critical to analyze?
Fuel flow rate and starter acceleration
Oil temperature
Cooling water pressure
Shaft alignment
During inspection, air intake ducts show minor corrosion. What analysis should be performed?
Increase fuel flow to compensate for the corrosion
Ignore because it is a normal wear and tear of the component
Evaluate impact on airflow and turbine efficiency
Reduce RPM during startup and then observe after a period of time
Starter fails to disengage after self-sustaining speed. Which subsystem analysis is needed?
Starter system and interlocks
Lubrication system
Cooling system
Exhaust system
Why analyze previous logbook entries before startup?
Identify recurring issues and preventive measures
Verify exhaust gas temperature
Align propeller shaft
Test fuel system pressure
If control system alarms repeatedly, what analysis should be conducted?
Purge combustion chamber and then operate engine again
Sensor calibration, interlock status, and wiring integrity
Lubricate bearings to eliminate friction that possibly causes the alarms
Replace fuel filter and then restart the system
What can be inferred (concluded) if self-sustaining speed is delayed?
Control system functioning imperfectly
Excess lubrication that adds load to the moving components
Due to normal wear and tear of the engine
Possible insufficient air pressure, fuel delivery issues, or starter inefficiency
During startup, compressor surge is observed. Which factors should be analyzed?
Airflow, FOD, and compressor blade condition
Oil flow rate
Fuel temperature only
Cooling system pressure
Design a pre-start checklist that ensures turbine readiness. Which elements must be included?
Perform a basic visual check to verify leaks around the engine
Inspect lubrication systems and cooling water levels after engaging startup
Fuel, lubrication, cooling, control, safety systems, and FOD clearance all confirmed
Test the electrical circuits prior addressing any other operational requirements
How could a startup sequence be modified to prevent hot start in cold environments?
Limit the air intake and skip any temperature monitoring to accelerate ignition
Initiate the sequence without pre-lubrication or system temperature verification
Gradually introduce fuel while pre-warming key components
Override starter interlocks and engage full power immediately
Combining vibration and oil pressure monitoring, what proactive strategy can be implemented?
Continue operation until vibration levels become critical and alarms are triggered
Schedule early shutdown and maintenance interventions before catastrophic component failure
Reduce cooling water flow as a first response to abnormal readings
How can control and monitoring data be synthesized to improve efficiency?
Prioritize monitoring lubricating oil system parameters without reviewing other operational indicators
Monitor exhaust temperature in relation to changes in fuel demand
Adjust fuel flow, RPM, and load application dynamically based on sensor trends and real-time performance data
Bypass erratic sensor readings and rely on manual visual inspections to ensure correct parameter readings
Integrating fire detection and emergency stop systems, what procedure ensures safety?
Ensure that safety signage are posted or clearly marked around the equipment
Conduct isolated extinguisher checks without linking them to shutdown protocols
Inspect ventilation systems regularly to skip alarm and trip circuit verification
Activate alarms, confirm emergency shutdown readiness, and restrict access before and during startup operations
How can previous startup failures be used to design preventive measures?
Analyze the root causes of past incidents and incorporate improved procedures, staff training, and revised protocols
Continue utilizing existing procedures that has always been working, ensuring design perfection
Focus on lubrication checks even without addressing other contributing factors
Monitor exhaust gas temperature and consider system history or performance trends while in normal operation
Synthesize safe startup steps for a ship operating in high ambient temperatures. Which approach is correct?
Bypass lubrication checks and rely on natural convection cooling for faster startup
Introduce fuel quickly to achieve faster turbine acceleration regardless of heat load
Verify fuel, oil, cooling systems, and air quality, and monitor EGT closely to prevent thermal stress
Reduce ventilation rates to maintain pressure in the intake system and to prevent unnecessarily cooling of the system
How can multiple system checks be combined to ensure operational readiness?
Inspect the fuel system pressure after carrying out filter maintenance to ensure no fluctuations will occur during operation
Limit pre-start checks to compressor alignment and ignore emergency subsystems
Observe turbine inlet temperature trends after verifying auxiliary system readiness
Conduct sequential inspections, verify interlocks, test emergency shutdown systems, and log all results for reference
Designing a training scenario for engineers, what elements should it include?
Cover lubrication system procedures and deviate from emergency protocols
Focus on combustion chamber purging and temperature checks before and after startup
Startup sequence, abnormal condition handling, emergency response, and system troubleshooting exercises
Emphasize vibration monitoring data while addressing other diagnostic skills
How can a synthesis of cooling and lubrication system data improve turbine lifespan?
Do not ignore sensor data and rely entirely on manual operational adjustments
Monitor RPM exclusively while analyzing thermal balance or lubrication performance
Optimize oil and water flow rates to maintain safe component temperatures and minimize wear
Focus on exhaust gas behavior even without correlating it to component heat transfer
A turbine is started without purging the combustion chamber. What is the risk assessment?
Minor efficiency reduction that might slightly affect output but not safety-critical operations
No operational risk provided ignition occurs promptly
Only affects lubrication system and bearing wear
High risk of fire or explosion due to unburned fuel accumulation
Which action best demonstrates adherence to safe startup protocols?
Bypassing interlocks to shorten startup duration and achieve faster readiness
Verifying all interlocks, safety devices, and emergency shutdown systems before initiating startup
Relying on operator experience to override automatic safety checks
Ignoring auxiliary system readiness to expedite main system startup
How would you evaluate the effectiveness of a new turbine control system?
Compare startup performance, alarm responsiveness, and sensor accuracy against established benchmarks
Carry out sensor calibration to ensure that the RPM stays within limits
Measure fuel flow during a single startup attempt and then use it to compute future consumption
Check exhaust temperature trends and ensure that other diagnostics are unnecessary
If vibration persists after alignment, what is the safest course of action?
Operate at reduced power until the next maintenance period to minimize downtime
Increase fuel flow to stabilize turbine speed and reduce vibration amplitude
Shut down the system and conduct a thorough mechanical inspection before resuming operation
Delay analysis until the next scheduled voyage since the system is still running
How should abnormal EGT readings during startup be judged?
Abort the startup immediately and troubleshoot to prevent severe damage
As acceptable variation as long as turbine load is within rated capacity
Reduce oil pressure and cooling water flow to stabilize internal conditions
Ignore and continue startup since the readings may normalize after ignition
When evaluating turbine readiness, which factor is most critical?
Only shaft alignment and gearbox torque transmission efficiency
Only lubrication pressure and oil temperature within normal range
All safety, fuel, lubrication, cooling, and control systems are operational and verified
Only exhaust system backpressure and gas discharge measurements
Assessing the risk of starting a turbine in high ambient temperature with borderline oil pressure involves:
Recognizing a high risk of equipment damage due to inadequate lubrication.
Assuming normal operation as long as the turbine starts.
Ignoring oil pressure if temperature is within limits.
Expecting improved oil pressure as the turbine warms up.
Which practice reflects the best evaluation of safety compliance during operation?
Continuous monitoring and immediate corrective action in response to abnormal conditions
Bypassing interlocks for convenience if no alarms are triggered
Skipping alarm checks to save time during startup procedures
Operating without control system data as long as mechanical systems appear functional
A turbine repeatedly experiences hot starts. What evaluation action is most appropriate?
Increase cooling water flow during startup to prevent combustion instability
Ignore the condition and continue since the turbine still achieves ignition
Review fuel control settings, starter operation, and operator procedures to identify root causes
Only adjust lubrication pressure and oil filter flow rate
Which decision ensures operational safety when a foreign object is detected in the intake duct?
Purge the combustion chamber only before attempting ignition
Start the turbine carefully at low power to prevent intake surge
Proceed without checking to avoid delaying operational schedule
Stop immediately and remove the object before initiating startup
