MDE Flash Cards – SVE Study

MDE Unit 1 four strokes

1. Purpose of the Compression Stroke

Question: What is the primary purpose of the compression stroke in a four-stroke marine diesel engine?

C) To compress the air in the cylinder

8. Exhaust System in Diesel Engines

Question: What is the role of the exhaust system connected to the cylinder during the exhaust stroke?

C) It channels the exhaust gases out of the engine

8. Intake Stroke in Diesel vs. Gasoline Engines

Question: How does the intake stroke in a marine diesel engine differ from that in a gasoline engine?

A) Diesel engines intake pure air, while gasoline engines intake an air-fuel mixture

4. Effect on Air Temperature During Compression Stroke

Question: What happens to the temperature of the air inside the cylinder during the compression stroke in a marine diesel engine?

C) It increases

6. Compression Ratio in Diesel Engines

Question: Why is the compression ratio typically higher in diesel engines compared to gasoline engines?

C) To ensure the air is hot enough to ignite the fuel

7. Role of the Power Stroke in Engine Operation

Question: Why is the power stroke considered the most critical stroke in the operation of a four-stroke marine diesel engine?

C) It generates the force needed to produce mechanical work

5. Timing of Fuel Injection

Question: When is fuel typically injected into the cylinder of a marine diesel engine?

C) At the end of the compression stroke

8. Common Issues During Compression Stroke

Question: What could be a possible cause of reduced compression in a marine diesel engine?

C) Worn piston rings or cylinder liner

5. Pressure Changes During Exhaust Stroke

Question: What happens to the pressure inside the cylinder during the exhaust stroke of a four-stroke marine diesel engine?

C) It decreases as the piston moves upward

5. Energy Conversion During Power Stroke

Question: What type of energy is primarily converted into mechanical work during the power stroke of a marine diesel engine?

A) Chemical energy from the fuel

7. Engine Governors

Question: What is the primary function of the governor in a marine diesel engine?

B) To control the engine’s speed

5. Timing of the Intake Stroke

Question: When does the intake stroke begin in the four-stroke cycle of a marine diesel engine?

C) Immediately after the exhaust stroke

4. Air-Fuel Mixture in Intake Stroke

Question: What is drawn into the cylinder during the intake stroke in a marine diesel engine?

C) Pure air

3. Piston Movement in Intake Stroke

Question: In which direction does the piston move during the intake stroke of a four-stroke marine diesel engine?

B) Downward away from the cylinder head

2. Cooling Systems

Question: What is the most likely cause of an increase in jacket water temperature in a marine diesel engine?

C) Insufficient coolant circulation

6. Starting Systems

Question: Which of the following methods is commonly used to start a large marine diesel engine?

B) Compressed air start

7. Role of the Compression Stroke in Power Output

Question: How does the compression stroke affect the power output of a marine diesel engine?

C) It prepares the air for combustion, indirectly contributing to power output

3. Piston Movement in Compression Stroke

Question: In which direction does the piston move during the compression stroke of a four-stroke marine diesel engine?

B) Upward toward the cylinder head

6. Compression Ratio in Diesel Engines

Question: Why is the compression ratio typically higher in diesel engines compared to gasoline engines?

C) To ensure the air is hot enough to ignite the fuel

1. Combustion in Marine Diesel Engines

Question: What is the main purpose of the turbocharger in a marine diesel engine?

B) To increase the engine’s air intake pressure

3. Valve Operation During Power Stroke

Question: Which valves are open during the power stroke of a four-stroke marine diesel engine?

D) Both valves are closed

4. Fuel Injection Systems

Question: In a marine diesel engine, what is the purpose of the fuel injector?

C) To atomize the fuel and inject it into the combustion chamber

1. Purpose of the Power Stroke

Question: What is the primary purpose of the power stroke in a four-stroke marine diesel engine?

C) To convert the energy from combustion into mechanical work

9. Scavenge Systems

Question: What is the purpose of the scavenging system in a two-stroke marine diesel engine?

B) To remove exhaust gases and fill the cylinder with fresh air

2. Piston Movement During Power Stroke

Question: In which direction does the piston move during the power stroke of a four-stroke marine diesel engine?

B) Downward away from the cylinder head

4. Effect on Air Temperature During Compression Stroke

Question: What happens to the temperature of the air inside the cylinder during the compression stroke in a marine diesel engine?

C) It increases

2. Valve Operation During Exhaust Stroke

Question: During the exhaust stroke of a four-stroke marine diesel engine, which valve is open?

B) Exhaust valve

Components in a Cross-Section of a Four-Stroke Diesel Engine Piston

Question: In a cross-section view of a four-stroke diesel engine piston, which of the following components are typically visible?

A) Piston crown, piston rings, and piston skirt

3. Lubrication Systems

Question: Which of the following is the primary function of a lubricating oil system in a marine diesel engine?

C) To reduce friction between moving parts

6. Pressure in the Cylinder During Intake

Question: What happens to the pressure inside the cylinder during the intake stroke of a four-stroke marine diesel engine?

B) It decreases slightly

10. Supercharging

Question: Which of the following is a benefit of supercharging in a marine diesel engine?

B) Increased engine efficiency and power output

1. Purpose of the Exhaust Stroke

Question: What is the primary purpose of the exhaust stroke in a four-stroke marine diesel engine?

C) To expel combustion gases from the cylinder

Factors Influencing Atomization

Question: Which of the following factors influence the atomization of fuel in a marine diesel engine?

A) Fuel temperature and injection pressure

Factors Influencing Penetration

Question: Which of the following factors primarily influence the penetration of fuel in the combustion chamber of a marine diesel engine?

A) Fuel temperature and injector nozzle design

Penetration in Fuel Combustion

Question: What does the term "penetration" refer to in the context of fuel combustion in a marine diesel engine?

B) The distance fuel droplets travel into the combustion chamber before igniting

Atomization in Fuel Combustion

Question: What is meant by the term "atomization" in the context of fuel combustion in a marine diesel engine?

B) The conversion of fuel into fine droplets to enhance combustion efficiency

5. Timing of Fuel Injection

Question: When is fuel typically injected into the cylinder of a marine diesel engine?

C) At the end of the compression stroke

Compression Ratio in Fuel Combustion

Question: What does the term "compression ratio" refer to in the context of fuel combustion in a marine diesel engine?

C) The ratio of the maximum to the minimum volume of the combustion chamber during the engine cycle

Transfer of Gas Force from Piston Crown to Crankshaft

Question: How is the force generated by the combustion gases transferred from the piston crown to the crankshaft in a four-stroke diesel engine?

A) Through the connecting rod which converts the linear motion of the piston into rotational motion

4. Timing of the Exhaust Stroke

Question: When does the exhaust stroke occur in the four-stroke cycle of a marine diesel engine?

B) Immediately after the power stroke

7. Significance of the Intake Stroke

Question: Why is the intake stroke crucial for the operation of a four-stroke marine diesel engine?

B) It ensures the cylinder is filled with a fresh charge of air for combustion

4. Combustion Process in Power Stroke

Question: What initiates the power stroke in a four-stroke marine diesel engine?

C) Spontaneous ignition of the fuel due to high pressure and temperature

3. Piston Movement During Exhaust Stroke

Question: In which direction does the piston move during the exhaust stroke of a four-stroke marine diesel engine?

A) Upward toward the cylinder head

2. Valve Operation During Compression Stroke

Question: During the compression stroke of a four-stroke marine diesel engine, which valves are closed?

A) Both intake and exhaust valves

8. Temperature Changes During Power Stroke

Question: What happens to the temperature inside the cylinder during the power stroke of a four-stroke marine diesel engine?

D) It starts high and decreases as the piston moves downward

7. Potential Issues During Exhaust Stroke

Question: What could happen if the exhaust valve fails to open properly during the exhaust stroke of a marine diesel engine?

C) The combustion gases will remain in the cylinder, causing poor performance

8. Fuel Systems

Question: Which of the following is a common cause of fuel injection pump failure in marine diesel engines?

B) Contaminated fuel

5. Exhaust Systems

Question: What is the primary purpose of the exhaust valve in a marine diesel engine?

A) To release burned gases from the combustion chamber

7. Role of the Compression Stroke in Power Output

Question: How does the compression stroke affect the power output of a marine diesel engine?

C) It prepares the air for combustion, indirectly contributing to power output

2. Valve Operation During Compression Stroke

Question: During the compression stroke of a four-stroke marine diesel engine, which valves are closed?

A) Both intake and exhaust valves

3. Piston Movement in Compression Stroke

Question: In which direction does the piston move during the compression stroke of a four-stroke marine diesel engine?

B) Upward toward the cylinder head

Factors Influencing Compression Ratio

Question: Which of the following factors primarily influence the compression ratio in a marine diesel engine?

A) Cylinder volume and piston design

2. Valve Operation During Intake Stroke

Question: During the intake stroke of a four-stroke marine diesel engine, which valve is open?

B) Intake valve

6. Exhaust Stroke and Engine Efficiency

Question: How does the exhaust stroke impact the overall efficiency of a marine diesel engine?

D) It maintains efficiency by ensuring complete removal of exhaust gases

Working Principle of the Four-Stroke Cycle

Question: Which of the following correctly describes the working principle of the four-stroke cycle in a marine diesel engine?

C) Intake, Compression, Power, Exhaust

8. Common Issues During Compression Stroke

Question: What could be a possible cause of reduced compression in a marine diesel engine?

C) Worn piston rings or cylinder liner

1. Purpose of the Compression Stroke

Question: What is the primary purpose of the compression stroke in a four-stroke marine diesel engine?

C) To compress the air in the cylinder

1. Purpose of the Intake Stroke

Question: What is the primary purpose of the intake stroke in a four-stroke marine diesel engine?

C) To draw fresh air into the cylinder

6. Timing of the Power Stroke

Question: When does the power stroke occur in the four-stroke cycle of a marine diesel engine?

C) Immediately after the compression stroke

1 / 59

MDE Unit 2 Piston Rings

Desirable Properties of Piston Rings

Question: Which of the following are THREE desirable properties of piston rings in a marine diesel engine?

A) High thermal conductivity, low wear rate, and effective sealing

Correcting Slight Loss of Timing Drive Tension

Question: How can slight loss of tension in engine timing belts or chains be corrected?

B) By adjusting the tensioner or idler pulleys to restore proper tension

Components of a Timing Chain Link

Question: What components are typically found in a timing chain link?

A) Chain links, rollers, and side plates

5. Timing Chain Tensioner Function

Question: What is the role of the timing chain tensioner in the timing chain system?

B) To maintain the correct tension in the timing chain

1. Sources of Thermal Efficiency Losses

Question: In a diesel engine, where may thermal efficiency losses commonly occur?

B) In the combustion chamber and exhaust system

2. Role of Rollers in a Timing Chain

Question: What role do rollers play in a timing chain system?

B) They reduce friction and wear between the chain and sprockets

6. Timing Chain Guide Purpose

Question: What is the purpose of the timing chain guide?

B) To guide the timing chain and prevent it from deviating from its path

1. Chain Tension Check

Question: During a drive inspection of a chain-driven camshaft, why is it important to check the chain tension?

C) To prevent excessive wear and noise, and to ensure proper timing

Materials Used for Piston Rings

Question: Which of the following materials are commonly used for manufacturing piston rings in marine diesel engines?

A) Cast iron, chrome-plated steel, and high-carbon steel

6. Influence of Turbocharger on Efficiency

Question: How does a turbocharger impact the thermal and mechanical efficiency of a diesel engine?

B) It increases the engine’s intake air pressure, leading to improved combustion efficiency and power output

3. Impact of Incomplete Combustion on Efficiency

Question: How does incomplete combustion affect the thermal efficiency of a diesel engine?

B) It results in a loss of energy and increases exhaust gas temperature

2. Chain Wear Examination

Question: What is the purpose of examining the wear of a chain in a chain-driven camshaft system?

C) To determine if the chain has stretched or elongated, affecting timing

5. Chain Lubrication Inspection

Question: What should be checked regarding chain lubrication during a camshaft drive inspection?

A) The amount of chain lubrication and its distribution

4. Purpose of Timing Chain Sprockets

Question: What is the purpose of the sprockets in a timing chain system?

B) To guide and drive the timing chain, synchronizing engine components

6. Camshaft Gear Teeth Condition

Question: During a drive inspection, why should the condition of the camshaft gear teeth be examined?

A) To check for cracks or damage that might affect the gear's engagement with the chain

Importance of Clearances for Piston Rings

Question: Why are the clearances necessary for efficient piston ring functioning in a marine diesel engine?

A) To allow for thermal expansion, prevent binding, and ensure smooth operation

Clearances for Efficient Piston Ring Functioning

Question: Which of the following THREE clearances are necessary for efficient piston ring functioning in a marine diesel engine?

A) End clearance, radial clearance, and side clearance

Necessity of Piston Rings

Question: Why are piston rings necessary in a marine diesel engine?

B) To maintain a seal between the piston and cylinder wall, control oil consumption, and support combustion pressure

2. Mechanical Efficiency Losses

Question: What are common sources of mechanical efficiency losses in a diesel engine?

B) In the friction between engine components and parasitic losses from accessories

4. Inspection for Chain Slippage

Question: How does checking for chain slippage contribute to the maintenance of a chain-driven camshaft system?

C) It detects if the chain has skipped teeth, affecting engine timing

1. Function of Timing Chain Links

Question: What is the primary function of the chain links in a timing chain system?

D) To transmit rotational motion between the sprockets

Effects of Loss of Timing Drive Tension

Question: How does a loss of tension in engine timing belts or chains affect the engine?

B) It can lead to incorrect valve timing, causing engine misfires and potential damage

Types of Piston Ring Ends

Question: Which of the following are THREE different types of piston ring ends used in marine diesel engines?

B) Flat, rounded, and serrated

Piston Ring End Clearance

Question: Why is piston ring end clearance necessary in a marine diesel engine?

A) To allow for thermal expansion and prevent the rings from binding in the cylinder

3. Function of Side Plates in a Timing Chain

Question: What is the function of the side plates in a timing chain?

A) To keep the chain aligned and secure

4. Effects of Engine Friction on Mechanical Efficiency

Question: What effect does engine friction have on mechanical efficiency?

B) It decreases the engine’s power output and mechanical efficiency

5. Role of the Cooling System in Efficiency

Question: How does the cooling system impact the thermal efficiency of a diesel engine?

B) It prevents overheating, which helps maintain optimal combustion temperatures and efficiency

3. Alignment of the Camshaft and Crankshaft

Question: Why is it important to check the alignment of the camshaft and crankshaft during a drive inspection?

C) To ensure proper timing and efficient engine operation

1 / 28

MDE Unit 3 Chain and Belt driven camshaft timing, tappets

Four-Stroke Timing Diagram

Question: What does a four-stroke timing diagram illustrate?

B) The synchronization of valve openings and closings with the piston positions during the four-stroke cycle

1. Valve Operation during the Intake Stroke

Question: In a four-stroke engine timing diagram, what happens to the intake valve during the intake stroke?

B) The intake valve is open to allow air-fuel mixture into the cylinder

1. Function of Timing Chain Links

Question: What is the primary function of the chain links in a timing chain system?

D) To transmit rotational motion between the sprockets

2. Role of Rollers in a Timing Chain

Question: What role do rollers play in a timing chain system?

B) They reduce friction and wear between the chain and sprockets

2. Valve Operation during the Compression Stroke

Question: What is the position of the valves during the compression stroke in a four-stroke engine timing diagram?

B) The intake valve is closed, and the exhaust valve is closed

Components of a Timing Chain Link

Question: What components are typically found in a timing chain link?

A) Chain links, rollers, and side plates

6. Timing Chain Guide Purpose

Question: What is the purpose of the timing chain guide?

B) To guide the timing chain and prevent it from deviating from its path

5. Timing of Fuel Injection

Question: In a four-stroke timing diagram, when does the fuel valve typically operate?

A) Just before the intake valve closes and the compression stroke begins

5. Chain Lubrication Inspection

Question: What should be checked regarding chain lubrication during a camshaft drive inspection?

A) The amount of chain lubrication and its distribution

Purpose of Double (Nested) Valve Springs

Question: Why might double (nested) valve springs be fitted in a four-stroke diesel engine?

C) To prevent valve float at high engine speeds and ensure consistent valve operation

4. Purpose of Timing Chain Sprockets

Question: What is the purpose of the sprockets in a timing chain system?

B) To guide and drive the timing chain, synchronizing engine components

Importance of Tappet Clearances

Question: Why is maintaining proper tappet clearance important in an engine?

C) To ensure proper valve operation, avoid excessive wear, and maintain engine performance

3. Alignment of the Camshaft and Crankshaft

Question: Why is it important to check the alignment of the camshaft and crankshaft during a drive inspection?

C) To ensure proper timing and efficient engine operation

6. Timing of Valve Openings and Closings

Question: How is the timing of the valve openings and closings shown in a four-stroke timing diagram?

B) As overlapping lines representing the duration each valve is open or closed relative to the piston position

3. Valve Operation during the Power Stroke

Question: In a four-stroke engine timing diagram, what occurs with the valves during the power stroke?

C) The intake valve remains closed, and the exhaust valve remains closed

Effects of Too Small Tappet Clearance

Question: What are the effects of having too small a tappet clearance on the exhaust valves of a four-stroke diesel engine?

B) Overheating of the valves, potential for incomplete valve closure, and increased wear on the valve train

6. Camshaft Gear Teeth Condition

Question: During a drive inspection, why should the condition of the camshaft gear teeth be examined?

A) To check for cracks or damage that might affect the gear's engagement with the chain

2. Chain Wear Examination

Question: What is the purpose of examining the wear of a chain in a chain-driven camshaft system?

C) To determine if the chain has stretched or elongated, affecting timing

Procedure for Setting Tappet Clearance

Question: What is the correct procedure for setting tappet clearance on diesel engine inlet/exhaust valves?

D) Measure the clearance with the engine cold, adjust the tappets using a feeler gauge, and then recheck the clearance with the engine at top dead center of the compression stroke.

Meaning and Purpose of Valve Overlap

Question: What does the term "valve overlap" refer to, and what is its purpose in an engine?

B) Valve overlap refers to the period when both the intake and exhaust valves are open simultaneously. Its purpose is to enhance the engine’s performance by improving the scavenging of exhaust gases and increasing the intake of fresh air.

4. Valve Operation during the Exhaust Stroke

Question: What is the position of the valves during the exhaust stroke in a four-stroke engine timing diagram?

B) The intake valve remains closed, and the exhaust valve opens

1. Chain Tension Check

Question: During a drive inspection of a chain-driven camshaft, why is it important to check the chain tension?

C) To prevent excessive wear and noise, and to ensure proper timing

3. Function of Side Plates in a Timing Chain

Question: What is the function of the side plates in a timing chain?

A) To keep the chain aligned and secure

5. Timing Chain Tensioner Function

Question: What is the role of the timing chain tensioner in the timing chain system?

B) To maintain the correct tension in the timing chain

4. Inspection for Chain Slippage

Question: How does checking for chain slippage contribute to the maintenance of a chain-driven camshaft system?

C) It detects if the chain has skipped teeth, affecting engine timing

Effects of Loss of Timing Drive Tension

Question: How does a loss of tension in engine timing belts or chains affect the engine?

B) It can lead to incorrect valve timing, causing engine misfires and potential damage

Effects of Too Large Tappet Clearance

Question: What are the effects of having too large a tappet clearance on the exhaust valves of a four-stroke diesel engine?

B) Poor engine performance, increased valve train wear, and potential for valve damage

Correcting Slight Loss of Timing Drive Tension

Question: How can slight loss of tension in engine timing belts or chains be corrected?

B) By adjusting the tensioner or idler pulleys to restore proper tension

1 / 28

MDE Unit 4 turbo charger

4. Possible Cause: Intake System Blockage

Question: What is a potential cause of reduced boost pressure if there is a blockage in the intake system?

A) A blocked or restricted intake pipe or manifold

2. Disadvantages of Pulse Systems

Question: What is a potential disadvantage of using a pulse system in a turbocharged diesel engine?

A) Increased complexity and cost due to additional components and tuning requirements

2. Impact of Air Cooler on Engine Performance

Question: How does an air cooler improve the performance of a diesel engine when fitted after a turbocharger?

A) By reducing fuel consumption and increasing power output

1. Advantages of Pulse Systems

Question: What is one of the main advantages of using a pulse system in a turbocharged diesel engine?

B) It enhances the efficiency of the turbocharger by improving turbine response and reducing turbo lag

Components of a Resilient/Flexible Engine Mounting

Question: In a cross section through a resilient/flexible mounting for a diesel engine, what are the MAIN components typically found? (Select THREE)

A) Mounting brackets, B) Vibration isolators, D) Rubber or elastomeric pads

2. Malfunctioning Turbocharger or Worn Turbine Blades

Question: What is a basic maintenance routine that could help with a malfunctioning turbocharger or worn turbine blades?

A) Check and clean the turbocharger air intake and exhaust areas

Purpose of Tube Fins in Air Coolers

Question: What is the purpose of tube fins in air coolers?

A) To increase the surface area for heat exchange, enhancing the cooling efficiency

1. Basic Function of a Turbocharger

Question: What is the primary function of a turbocharger in a main engine?

B) To increase the air intake pressure, allowing more air to enter the engine cylinders

2. Possible Cause: Turbocharger Failure

Question: What could be a reason for a reduction in boost pressure over time in a turbocharged engine?

A) A malfunctioning turbocharger or worn turbine blades

3. Damaged or Clogged Charge Air Cooler

Question: What is an economical maintenance routine to address a damaged or clogged charge air cooler?

A) Inspect and clean the charge air cooler, and replace it if necessary

Thrust Bearing in Turbochargers

Question: Why is a thrust bearing necessary in a large medium-speed diesel engine turbocharger?

B) To absorb axial forces generated by the high-speed rotation of the turbocharger's compressor and turbine wheels

Turbocharger Cooling

Question: How is the turbocharger typically cooled in a marine diesel engine?

B) By the circulation of lubricating oil through the turbocharger bearings and water jackets

Purpose of Labyrinth Glands in Turbochargers

Question: What is the primary purpose of labyrinth glands in the construction of a diesel engine turbocharger?

B) To prevent the leakage of lubricating oil and seal the gap between the rotating shaft and stationary components

Indications of Poor Turbocharger Performance

Question: What are possible indications of poor turbocharger performance? (Select FOUR)

A) Increased turbo lag and delayed acceleration, B) Excessive exhaust smoke or black smoke from the engine, D) Unusual whining or rattling noises from the turbocharger, F) Reduced power output and overall engine performance

Purpose of Fins on Charge Air Cooler Tubes

Question: Why are fins attached to the tubes of a charge air cooler?

A) To increase the surface area for heat dissipation and enhance the cooling efficiency of the air

Pulse System in Turbochargers

Question: What is meant by the term "pulse system" in the context of large medium-speed diesel engine turbochargers?

B) A system that utilizes a series of exhaust gas pulses to improve the efficiency of the turbocharger by enhancing turbine response and performance

Purpose of the Nozzle Ring in Turbochargers

Question: What is the primary purpose of the nozzle ring in a main engine turbocharger?

B) To direct and accelerate exhaust gases onto the turbine wheel for improved energy extraction

1. Possible Cause: Air Leak

Question: What is one possible cause of reduced boost pressure at the inlet manifold in a turbocharged engine fitted with a charge air cooler?

B) An air leak in the intake system or charge air cooler

3. Cooling Medium for Air Coolers

Question: What medium is commonly used to cool the air in an intercooler fitted after a turbocharger?

B) Engine coolant (water or antifreeze)

5. Turbocharger Efficiency

Question: How can the efficiency of a turbocharger be improved?

B) By optimizing the turbine and compressor design to reduce energy losses

1. Air Leak in Intake System or Charge Air Cooler

Question: What is a simple and economical maintenance routine to address an air leak in the intake system or charge air cooler?

A) Tighten all intake and charge air cooler clamps and inspect for visible damage

Purpose of the Volute Casing in Turbochargers

Question: What is the primary purpose of the volute casing in a main engine turbocharger?

B) To collect and direct compressed air from the compressor wheel into the engine's intake manifold

Location of Thrust Bearing in Turbochargers

Question: Where is the thrust bearing typically fitted in a large medium-speed diesel engine turbocharger?

C) On the shaft between the compressor side and the bearing housing

Lubrication of Thrust Bearing in Turbochargers

Question: How is the thrust bearing typically lubricated in a large medium-speed diesel engine turbocharger?

D) By the engine’s lubricating oil system, which circulates oil through the turbocharger bearing housing

5. Maintenance of Air Coolers

Question: What is an important maintenance task for ensuring the efficient operation of air coolers in a turbocharged diesel engine?

B) Cleaning the air cooler to remove any buildup of dirt or oil

Turbocharger Lubrication

Question: How is a turbocharger typically lubricated in a marine diesel engine?

B) By circulating engine lubricating oil through the turbocharger bearings under pressure

Purpose of the Diffuser in Turbochargers

Question: What is the primary purpose of the diffuser in a main engine turbocharger?

B) To slow down the high-velocity air exiting the compressor and convert its kinetic energy into pressure

4. Turbocharger and Exhaust Gases

Question: What role do exhaust gases play in the operation of a turbocharger?

B) They power the turbine, which drives the compressor

Purpose of Zinc Anodes in Air Coolers

Question: What is the purpose of zinc anodes in air coolers?

B) To prevent corrosion by providing a sacrificial material that corrodes instead of the cooler components

3. Impact on Engine Performance

Question: How does a turbocharger affect the performance of a diesel engine?

B) It increases the engine's power output by compressing more air into the cylinders

Purpose of the Diffuser in Turbochargers

Question: What is the primary purpose of the diffuser in the construction of a diesel engine turbocharger?

C) To slow down the high-velocity air exiting the compressor and convert kinetic energy into increased pressure

3. Possible Cause: Charge Air Cooler Issues

Question: Which issue related to the charge air cooler could cause a decrease in boost pressure?

A) A damaged or clogged charge air cooler

4. Blocked or Restricted Intake Pipe or Manifold

Question: What is a simple maintenance task to address a blocked or restricted intake pipe or manifold?

A) Inspect and clean the intake pipe and manifold to remove any obstructions

3. Troubleshooting Pulse System Issues

Question: What could be a symptom of a problem with the pulse system in a turbocharged diesel engine?

B) Reduced engine responsiveness and increased turbo lag

5. Effect of Pulse System on Exhaust Temperature

Question: How does a pulse system typically affect the exhaust temperature in a turbocharged diesel engine?

C) It may increase exhaust temperature by optimizing the utilization of exhaust gases

Special Considerations for Engine Installation with Resilient/Flexible Mountings

Question: What is a special consideration necessary with respect to engine installation when using a resilient/flexible mounting for a diesel engine?

D) Properly securing the resilient/flexible mounts to prevent excessive movement and alignment issues

2. Components of a Turbocharger

Question: Which of the following components are essential parts of a turbocharger?

A) Compressor wheel and turbine wheel

Purpose of the Thrust Bearing in Turbochargers

Question: What is the primary purpose of the thrust bearing in the construction of a diesel engine turbocharger?

B) To absorb and manage the axial forces generated by the high-speed rotation of the turbocharger shaft

Possible Causes of Poor Turbocharger Performance

Question: What are possible causes of poor turbocharger performance? (Select FOUR)

A) A clogged air filter, C) An air leak in the intake system, D) A worn-out or damaged turbocharger turbine, E) A restricted exhaust system

Purpose of the Inducer in Turbochargers

Question: What is the primary purpose of the inducer in the construction of a diesel engine turbocharger?

B) To draw in and compress the intake air before it enters the compressor wheel

4. Consequence of a Faulty Air Cooler

Question: What is a likely consequence if an air cooler fails or becomes inefficient on a turbocharged diesel engine?

C) Higher intake air temperature, leading to reduced engine efficiency and increased risk of knocking

5. Possible Cause: Boost Control Issues

Question: What boost control issue could lead to a decrease in boost pressure in a turbocharged engine?

A) A faulty wastegate or boost control valve

Cooling the Air Outlet from the Turbocharger

Question: Why should the air outlet from the turbocharger be cooled before entering the diesel engine cylinder?

B) To lower the temperature of the air, increasing its density and improving combustion efficiency

4. Maintenance of Pulse Systems

Question: What is an important maintenance consideration for ensuring the proper function of a pulse system in a turbocharged engine?

B) Ensuring proper alignment and integrity of the pulse piping and valves

1. Purpose of Air Coolers After Turbochargers

Question: Why are air coolers (intercoolers) typically fitted after the main engine turbochargers?

B) To decrease the temperature of the intake air, increasing its density and improving engine efficiency

5. Faulty Wastegate or Boost Control Valve

Question: What routine maintenance can be performed to address a faulty wastegate or boost control valve?

A) Inspect and clean the wastegate and boost control valve, and check for proper operation

Purpose of Vent Cocks in Air Coolers

Question: What is the purpose of vent cocks in air coolers?

A) To allow the release of trapped air or gases from the cooling system

Possible Reasons for Reduced Charge Air Cooler Performance

Question: What are possible reasons why the performance of a charge air cooler may be reduced?

A) Accumulation of dirt and debris on the cooler fins

1 / 48

MDE Unit 5 injectors

Question 3: What defect can lead to erratic engine operation and knocking?

A) Incorrect spray pattern

Preventing Fuel Spray from High-Pressure Pipe Failure in Scroll Type Fuel Injection Pumps

Question: In scroll type fuel injection pumps, how is fuel oil prevented from spraying out if the high-pressure pipe fails in service?

A) By using a pressure relief valve to divert excess fuel

4. Effects of Fuel Pressure on Nozzle Operation

Question: How does high fuel pressure affect the operation of a diesel engine fuel nozzle?

B) It increases the spray pattern's spread and improves atomization

Purpose of the Delivery Valve in Scroll Type Fuel Injection Pumps

Question: What is the purpose of the delivery valve in scroll type fuel injection pumps?

C) To prevent backflow of fuel from the high-pressure side to the low-pressure side

Fuel Metering in Scroll Type Fuel Pumps

Question: How does a scroll type fuel pump meter fuel for high and low loads?

C) By varying the displacement of the scroll mechanism

1. Operation of a Diesel Engine Fuel Nozzle

Question: What is the primary function of a diesel engine fuel nozzle?

B) To inject fuel into the combustion chamber at high pressure

2. Purpose of Fuel Atomization

Question: Why is fuel atomization important in a diesel engine fuel nozzle?

B) To ensure the fuel mixes thoroughly with air for efficient combustion

Question 4: Which defect in a fuel injector can cause reduced fuel efficiency and increased fuel consumption?

B) Poor injector atomization

Defects in Main Engine Fuel Injectors

Question 1: What is a common defect in fuel injectors that results in poor engine performance and increased exhaust smoke?

A) Clogged nozzle orifices

Main Components of a Fuel Injector Nozzle

Question: What are the MAIN components found in a cross section through the nozzle of a fuel injector? (Select THREE)

A) Nozzle tip, C) Needle valve, E) Spring

5. Common Issues with Diesel Fuel Nozzles

Question: What is a common issue that can affect the performance of a diesel engine fuel nozzle?

A) Clogged nozzle orifices

Effects of Advanced Fuel Injection in Four-Stroke Engines

Question: What are the effects of advanced fuel injection in a four-stroke engine?

B) Improved power output and reduced exhaust emissions

Question 2: Which defect in a fuel injector can cause fuel to leak into the combustion chamber continuously?

C) Leaking nozzle seals

Components of a Scroll Type Fuel Pump

Question: Which of the following labels the MAIN components of a scroll type fuel pump?

A) Scroll mechanism, camshaft, delivery valve, and pump housing

Understanding Penetration

Question: What does the term "penetration" refer to in the context of diesel engine fuel injection?

A) The depth to which fuel droplets penetrate into the combustion chamber

Effects of Low Compression Pressure in Four-Stroke Engines

Question: What are the effects of low compression pressure in a four-stroke engine?

A) Increased fuel consumption and reduced power output

Purpose of the Delivery Valve in Bosch or Jerk Type Fuel Injection Pumps

Question: What is the purpose of the delivery valve in Bosch or Jerk type fuel injection pumps?

B) To prevent fuel leakage back into the pump after injection

Effects of Retarded Fuel Injection in Four-Stroke Engines

Question: What are the effects of retarded fuel injection in a four-stroke engine?

A) Increased engine knocking and reduced power output

3. Fuel Nozzle Construction

Question: Which component of a diesel engine fuel nozzle is responsible for controlling the spray pattern of the fuel?

A) The nozzle tip

Varying Delivered Quantity in Scroll Type Fuel Injection Pumps

Question: In scroll type fuel injection pumps, how is the delivered quantity of fuel varied?

C) By modifying the position of the scroll or cam mechanism

Question 5: What is a possible defect in fuel injectors that may result in a rough engine idle and excessive exhaust smoke?

B) Leaking nozzle tip

Controlling Delivered Fuel Quantity in Bosch or Jerk Type Pumps

Question: In Bosch or Jerk type fuel injection pumps, how is the delivered quantity of fuel oil controlled?

C) By changing the position of the plunger within the pump cylinder

Defects in Diesel Engine Fuel Nozzles

Question: What are some defects that diesel engine fuel nozzles may encounter during service? (Select THREE)

A) Clogged nozzle orifices, B) Leaking nozzle seals, D) Corrosion or erosion of the nozzle tip

Understanding Atomization

Question: What is meant by atomization in the context of diesel engine fuel injection?

B) The process of breaking down fuel into fine droplets for efficient mixing with air

Fuel Metering in Scroll Type Fuel Pumps

Question: How does a scroll type fuel pump meter fuel for high and low loads?

C) By varying the displacement of the scroll mechanism

1 / 25

MDE Unit 6 crank case

Checks and Investigations for Increased Crankcase Pressure

Question 1: What is the first step an engineer should take when investigating increased crankcase pressure?

B) Check the crankcase ventilation system for blockages or malfunctions

Question 5: What is a potential consequence of not addressing high crankcase pressure promptly?

C) Risk of engine damage and potential failure

Circumstances Causing Relief Valves to Operate in Diesel Engine Crankcases

Question: Under what circumstances might relief valves in a diesel engine crankcase operate?

B) When there is excessive blow-by gas pressure or high crankcase pressure

Question 2: If the crankcase pressure is high, what should be checked to ensure proper sealing and pressure control?

B) Engine gaskets and seals

Question 3: What additional investigation should be conducted if crankcase pressure remains high despite checking the ventilation system and seals?

B) Examine the piston rings and cylinder walls for wear or damage

Question 4: What tool should be used to check for excessive blow-by gases that might be contributing to high crankcase pressure?

B) Cylinder compression tester

Crankcase Explosion Relief Door Components

Question: Which of the following lists the MAIN components of a crankcase explosion relief door?

A) Relief door, pressure spring, locking pin, and gasket

Purpose of Relief Valves in Diesel Engine Crankcases

Question: Why are relief valves fitted to diesel engine crankcases?

C) To prevent excessive pressure buildup and avoid crankcase damage

Further Actions After Crankcase Oil Mist Detector Activation

Question: After shutting down the engine due to activation of the crankcase oil mist detector, what additional actions should the on-watch engineer take?

B) Check for signs of oil leaks and inspect the crankcase ventilation system

High Crankcase Pressure Implications and Actions

Question: If the daily engine log shows that the engine crankcase pressure gauge is indicating a much higher value than the normal reading, what are the implications and immediate actions that should be taken?

B) High crankcase pressure may indicate potential issues such as excessive blow-by or ventilation problems; immediately shut down the engine and inspect the crankcase ventilation system and seals.

Safety Detection System in Diesel Engine Crankcases

Question: What is a common safety detection system that may be fitted to diesel engine crankcases?

C) Crankcase pressure sensor

Actions After Crankcase Oil Mist Detector Activation

Question: What actions should the on-watch engineer take when the engine crankcase oil mist detector activates?

B) Shut down the engine immediately and investigate the cause

1 / 12

MDE Unit 7 overspeed trip testing proceedures

9. Propeller Shaft Bearing Temperature Sensor

Question: Why is a temperature sensor fitted to the propeller shaft bearing?

B) To detect overheating in the bearing that could lead to failure

Question 4: What happens to the centrifugal overspeed trip mechanism if the engine speed returns to normal after an overspeed condition?

B) The trip mechanism automatically resets once the speed decreases

Overspeed Trip of the Centrifugal Type

Question 1: What is the primary purpose of an overspeed trip of the centrifugal type in a diesel engine?

C) To prevent engine damage by stopping the engine if it exceeds a predetermined speed

6. Vibration Sensor

Question: What is the purpose of a vibration sensor on a propulsion engine?

B) To monitor and detect abnormal vibrations that could indicate mechanical failure

Manual Testing of HT Cooling Water High-Temperature Alarm

Question 1: What is the first step in manually testing the set point for the high-temperature alarm on a diesel generator’s HT cooling water system?

C) Gradually heat the HT cooling water while monitoring the temperature

Question 2: Which safety cut-out is designed to prevent engine operation in the event of low oil pressure?

A) Oil pressure cut-out

Manual Testing of HT Cooling Water High-Temperature Shutdown

Question 2: How is the high-temperature shutdown set point manually tested on a diesel generator?

B) By gradually heating the HT cooling water until the shutdown occurs

5. Oil Mist Detector

Question: What is the reason for fitting an oil mist detector in a propulsion engine’s crankcase?

B) To detect the presence of oil mist that could indicate a crankcase explosion risk

Oil Pressure Cut-Out

Question 2: How does an oil pressure cut-out function in a diesel engine?

C) Monitors oil pressure and stops the engine when pressure is too low

Question 5: Which safety cut-out is specifically designed to detect and prevent excessive exhaust gas temperatures?

A) Exhaust temperature trip

Question 5: Which of the following is a common maintenance check for the centrifugal overspeed trip mechanism?

B) Inspecting the condition of the centrifugal weights and springs

Restoring Normal Operation After Testing

Question 4: What is the final step after manually testing the HT cooling water high-temperature alarm and shutdown on a diesel generator?

C) Reset the alarm and shutdown systems and return the HT cooling system to normal operation

7. Emergency Stop Button

Question: Why is an emergency stop button fitted to a propulsion engine control system?

B) To quickly shut down the engine in case of an emergency

Restoring Normal Operation After Testing

Question 4: After manually testing the lubricating oil low-pressure alarm and shutdown using a pressure calibrator, what should be the next step?

B) Reconnect the pressure sensor and reset the alarm and shutdown systems to their normal settings

4. Shaft Brake

Question: Why might a shaft brake be fitted to a propulsion engine?

B) To prevent the propeller from rotating when the engine is stopped

Overspeed Trip

Question 1: How does an overspeed trip function in a diesel engine?

B) Uses centrifugal force to activate the cut-out when speed exceeds the limit

Final System Check After Testing

Question 5: What is the purpose of performing a final system check after testing the lubricating oil low-pressure alarm and shutdown?

C) To confirm that the pressure alarm and shutdown system are functioning correctly after being reset

2. High-Temperature Alarm

Question: Why is a high-temperature alarm fitted to the cooling system of a propulsion engine?

B) To alert the crew of excessive engine temperature that could cause overheating and damage

Verifying Set Points on HT Cooling Water Alarm and Shutdown

Question 3: After manually testing the high-temperature alarm and shutdown set points, what should be done to verify the accuracy of these set points?

B) Record the temperatures at which the alarm and shutdown occurred and compare them with the set points

1. Low Oil Pressure Alarm

Question: What is the primary reason for fitting a low oil pressure alarm to a propulsion engine?

C) To warn of inadequate lubrication that could lead to engine damage

3. Overload Clutch

Question: What is the purpose of an overload clutch in a gearbox arrangement?

B) To protect the gearbox from damage due to excessive torque

Question 4: What is the purpose of a low fuel level cut-out in a diesel engine?

C) To stop the engine if the fuel level falls below a certain point

Question 3: What component of the centrifugal overspeed trip mechanism is responsible for detecting excessive engine speed?

B) The centrifugal governor

Question 2: How does a centrifugal overspeed trip mechanism operate?

C) It relies on centrifugal force to actuate a trip mechanism that stops the engine when a certain speed is exceeded

Safety Cut-Outs/Trips for Diesel Engines

Question 1: What is the primary function of an overspeed trip in a diesel engine?

B) To stop the engine if it exceeds a specified speed

High Coolant Temperature Trip

Question 3: How does a high coolant temperature trip function in a diesel engine?

C) Senses coolant temperature and halts engine operation when overheating occurs

Manual Testing of Lubricating Oil Low-Pressure Shutdown

Question 2: During the manual testing of the lubricating oil low-pressure shutdown set point, what should you do if the shutdown does not activate at the expected pressure?

C) Verify the calibration of the pressure calibrator and retest

8. Gearbox Temperature Sensor

Question: What is the role of a gearbox temperature sensor in a propulsion engine arrangement?

B) To detect excessive heat that could damage the gearbox components

Verifying Set Points on Lubricating Oil Low-Pressure Alarm and Shutdown

Question 3: How should the set points be verified after manually testing the lubricating oil low-pressure alarm and shutdown?

B) Compare the alarm and shutdown activation pressures with the specified set points

Low Fuel Level Cut-Out

Question 4: How does a low fuel level cut-out function in a diesel engine?

B) Stops the engine when the fuel level drops below a certain threshold

Manual Testing of Lubricating Oil Low-Pressure Alarm

Question 1: What is the first step in manually testing the set point for the low-pressure alarm on a diesel engine’s lubricating oil system using a pressure calibrator?

C) Gradually decrease the applied pressure using the pressure calibrator while monitoring the alarm system

10. Lube Oil Filter Differential Pressure Gauge

Question: What is the purpose of a differential pressure gauge on the lube oil filter in a propulsion engine?

B) To monitor the pressure difference across the filter and indicate when it needs cleaning or replacement

Question 3: What does a high coolant temperature trip do in a diesel engine?

B) It shuts down the engine if the coolant temperature exceeds a set threshold

1 / 33

MDE Unit 8 terminology

What does the term "overlap" refer to in the context of a diesel engine?

A) The period during which both the intake and exhaust valves are open

What does the term "afterburning" refer to in the context of a diesel engine?

B) The continuation of combustion after the fuel injection has ended

What is the purpose of a tell-tale ring in a tube-type heat exchanger?

B) To provide a visual indication of leakage between the shell and tube sides

What does the term "piston stroke" refer to in a diesel engine?

A) The distance the piston moves from the top dead centre (TDC) to the bottom dead centre (BDC)

What is the purpose of anodes in a tube-type heat exchanger?

B) To protect the heat exchanger from corrosion by acting as a sacrificial material

What does the term "clearance volume" refer to in a diesel engine?

B) The volume of the cylinder above the piston when it is at top dead centre (TDC)

What does the term "calorific value" refer to in the context of a diesel engine?

A) The amount of heat energy released during fuel combustion

What does the term "scavenging" refer to in the context of a diesel engine?

B) The process of removing exhaust gases from the cylinder and replacing them with fresh air

What does the term "swept volume" refer to in a diesel engine?

B) The volume of air or fuel mixture that is displaced by the piston during one complete stroke

What is the purpose of baffle plates in a tube-type heat exchanger?

B) To direct the flow of the fluid, increasing turbulence and improving heat transfer efficiency

What does "top dead centre" (TDC) refer to in the context of a diesel engine?

B) The point where the piston is at its highest position in the cylinder

What does the term "viscosity" refer to in the context of a diesel engine?

C) The measure of the fuel's resistance to flow, affecting its ability to be pumped and atomized

What is the purpose of a vent cock in a tube-type heat exchanger?

A) To release air or gas trapped inside the heat exchanger to prevent air locking

What does the term "compression" refer to in the context of a diesel engine?

B) The reduction in volume of air or air-fuel mixture in the cylinder before ignition

What is the purpose of a sliding tube plate in a tube-type heat exchanger?

B) To facilitate easy cleaning and maintenance of the heat exchanger

What does the term "expansion" refer to in the context of a diesel engine?

B) The increase in volume of gases after combustion, driving the piston downward

What does "bottom dead centre" (BDC) refer to in the context of a diesel engine?

B) The point where the piston is at its lowest position in the cylinder

What does the term "compression ratio" refer to in a diesel engine?

B) The ratio of the volume of the cylinder when the piston is at bottom dead centre (BDC) to the volume when the piston is at top dead centre (TDC)

What does the term "density value" refer to in the context of a diesel engine?

B) The mass of the fuel per unit volume, indicating its concentration

What does the term "cetane number" refer to in the context of a diesel engine?

C) The measure of the fuel's ignition delay time and its ease of ignition

1 / 20

MDE Unit 9 oil, crude oil , fuel

With reference to microbial infestation of distillate fuel, which of the following is necessary for microbes to survive and grow?

C) Presence of water and suitable organic material

5. What is the function of a fuel oil heater in the distillate fuel supply system?

B) To maintain the fuel temperature to prevent wax formation

1. Which section of the MSDS for distillate fuel oil provides information on how to handle fires involving the fuel?

B) Fire-Fighting Measures

4. How can solid contaminants in distillate fuel oil lead to problems with fuel injectors?

B) They cause injector clogging and uneven fuel delivery

2. What is the primary purpose of regulating the temperature of bunker fuel storage in the engine room according to SOLAS guidelines?

B) To enhance the fuel’s energy content

What does the term "cloud point" refer to in fuel terms?

B) The temperature at which fuel becomes visibly cloudy due to the formation of wax crystals

How can fuel system and engine-related problems caused by microbial contamination be avoided?

A) Regularly inspect and clean fuel tanks and systems to remove water and sludge

4. Which distillation product is commonly used for cleaning and degreasing mechanical parts on a vessel?

B) Solvent

4. How does removing contaminants from distillate fuel oil help maintain engine performance?

A) It prevents clogging of fuel filters and injectors

With reference to diesel engine fuel, which of the following actions should be taken if microbial contamination is severe?

B) Replace the contaminated fuel and clean the fuel system thoroughly

3. What engine performance issue can arise from microbial contamination in distillate fuel oil?

B) Misfiring and rough engine operation due to clogged injectors

What potential problem can arise from the presence of wax in distillate fuel?

C) Blockage of fuel filters and lines in cold temperatures

2. In an MSDS for distillate fuel oil, which section would provide information about the potential health effects of exposure to the fuel?

C) Health Hazards Identification

With reference to diesel engine fuel, which of the following methods is effective in avoiding microbial contamination?

B) Using biocides to kill microorganisms in the fuel

With reference to diesel engine fuel, what does the term "microbial contamination" mean?

C) The growth of microorganisms, such as bacteria or fungi, in the fuel

Why is it important to know the flash point of the bunker fuel stored on board?

B) To ensure safe handling and prevent fire hazards

1. Which of the following methods is commonly used to determine the flashpoint of bunker fuel?

B) The Open Cup Method

4. What information might the "Fire-Fighting Measures" section of an MSDS include about protective equipment for firefighters?

A) Recommended types of respirators and personal protective equipment

With reference to microbial infestation of distillate fuel, which of the following are potential problems that can occur in a diesel engine?

B) Clogging of fuel filters and corrosion of fuel system components

3. Under SOLAS regulations, which of the following best describes the temperature control measures for bunker fuel storage in the engine room?

B) Bunker fuel must be maintained at a temperature below its flashpoint to prevent fire hazards

1. What is a common problem caused by solid contaminants in distillate fuel oil?

B) Corrosion and erosion of fuel system components

5. What potential problem does cooling distillate fuel oil help to mitigate after engine use?

B) The risk of fuel vaporization and associated safety hazards

5. How should firefighters handle fuel spills that occur during a fire involving distillate fuel oil, based on the "Fire-Fighting Measures" section of the MSDS?

A) Spread absorbent materials over the spill and use proper disposal methods

How can fuel system and engine-related problems caused by fuel incompatibility be avoided?

B) Ensure that any new fuel or additives are tested for compatibility with the existing fuel

How does contamination of fuel oil by sodium typically affect the fuel system?

B) It causes the formation of deposits on combustion surfaces and can lead to engine knock

3. What safety device in a distillate fuel supply system is designed to prevent overpressure conditions?

B) Pressure Relief Valve

According to ISO 8217, how do aluminium and silicon oxides typically get into marine fuel oil?

B) From the use of additives or contaminants introduced during refining

2. How do solid contaminants in distillate fuel oil affect the fuel filters?

B) They cause clogging and reduced efficiency of the filters

In the context of microbial infestation of distillate fuel, what is meant by the term "microbe"?

C) A microscopic organism, such as bacteria or fungi, that can grow in fuel

With reference to microbial infestation of distillate fuel, which of the following methods can be used to identify the presence of microbes?

C) Using fuel analysis tests to detect microbial contamination and sludge formation

How can fuel system and engine-related problems be avoided with reference to the cloud point of fuel?

A) Use fuel with a cloud point lower than the minimum operating temperature of the engine

4. How can microbial contamination in distillate fuel oil lead to corrosion problems?

A) Microbial activity produces acids that can corrode metal components

4. What should be done if someone ingests distillate fuel oil, according to the "First-Aid Measures" section of an MSDS?

B) Do not induce vomiting; seek immediate medical attention

1. Why is distillate fuel oil often treated before use in diesel engines?

B) To remove impurities and contaminants that can cause engine damage

3. Which of the following is a primary reason for removing water from distillate fuel oil before it is used in a diesel engine?

B) Water can lead to microbial growth and fuel degradation

3. How does cooling distillate fuel oil help in maintaining the integrity of fuel handling systems?

A) By preventing thermal degradation of the fuel and reducing the risk of fire

4. Which section of the MSDS for distillate fuel oil details the potential physical and chemical hazards associated with the fuel?

A) Stability and Reactivity

According to ISO 8217, what effect do aluminium and silicon oxides in marine fuel oil typically have on engine performance?

B) They cause abrasive wear and damage to engine components

How can the potential problem associated with a low flashpoint in distillate fuel be avoided?

B) By storing the fuel at temperatures well below its flashpoint

5. What kind of information related to emergency response might be included in the MSDS for distillate fuel oil?

A) Procedures for dealing with fuel spills and leaks

4. How can water contamination in distillate fuel oil lead to injector problems?

B) It causes injector clogging and uneven fuel delivery

4. What is the recommended practice for monitoring the temperature of bunker fuel storage according to SOLAS standards?

B) Installing automatic temperature monitoring systems with alarms

2. Which product derived from crude oil distillation is typically used for heating and cooling systems on a vessel?

C) Gas Oil

1. What type of hazard information is commonly found in a material safety datasheet (MSDS) for distillate fuel oil?

C) Health hazards and safety precautions

2. What type of information would you find in the "First-Aid Measures" section of an MSDS for distillate fuel oil if someone has inhaled the vapors?

C) Steps to take for moving the person to fresh air and seeking medical attention

3. What engine performance issue can arise from solid contaminants in distillate fuel oil?

B) Decreased engine performance due to clogged injectors

1. Which component of a typical distillate fuel supply system is responsible for regulating the pressure of the fuel before it enters the engine?

C) Fuel Pressure Regulator

1. Which of the following products obtained from the distillation of crude oil is commonly used as fuel for marine diesel engines?

B) Heavy Fuel Oil (HFO)

3. In the Cleveland Open Cup (COC) flashpoint test, how is the temperature at which the fuel emits a flammable vapor determined?

A) By heating the fuel and periodically applying a small flame above the surface

2. What is the primary purpose of the Cleveland Open Cup (COC) method in determining the flashpoint of bunker fuel?

B) To measure the temperature at which the fuel emits vapor that can ignite briefly

3. If distillate fuel oil gets into a person's eyes, what does the MSDS recommend in the "First-Aid Measures" section?

A) Flush eyes with water for at least 15 minutes and seek medical attention

3. What is a typical use of the product "Marine Diesel Oil" (MDO) on board a vessel?

B) As a fuel for auxiliary engines and generators

3. In the event of a fire involving distillate fuel oil, what precaution should be taken according to the "Fire-Fighting Measures" section of the MSDS?

C) Wear appropriate protective clothing and breathing apparatus

1. Which section of the MSDS for distillate fuel oil provides information on the actions to take if the fuel comes into contact with skin?

B) First-Aid Measures

4. Which device in the fuel supply system helps in detecting and addressing water contamination in the fuel?

B) Water Separator

What does the term "flashpoint" refer to in the context of bunker fuel stored on board?

B) The temperature at which the fuel emits enough vapor to ignite briefly when exposed to a flame

2. How does microbial contamination in distillate fuel oil affect the fuel filters?

B) It leads to clogging and reduced effectiveness of the filters

What potential problem can arise if the flashpoint of distillate fuel is too low?

B) Higher risk of vaporization and fire hazards

How does microbial contamination of fuel oil typically affect the fuel system?

B) It causes the formation of sludge, clogging fuel filters, and contributing to corrosion

How can potential problems caused by microbes in distillate fuel be avoided?

B) By using biocides to kill and control microbial contamination

How can fuel system and engine-related problems associated with the cloud point be avoided?

A) Select fuel with a cloud point lower than the minimum expected ambient temperature

1. According to SOLAS requirements, what is the maximum allowable temperature for bunker fuel storage in the engine room?

B) 70°C

2. How does water in distillate fuel oil affect the fuel filters?

B) It causes clogging and reduced efficiency of the filters

What potential problem can arise from microbial contamination in distillate fuel?

B) Corrosion of fuel system components and formation of sludge

5. Why might distillate fuel oil be treated to reduce its sulfur content before use in engines?

A) To prevent corrosion and damage to engine components

What does the term "compatibility" refer to in fuel terms?

A) The ability of different fuels to blend together without causing adverse reactions

4. Why is it important to cool distillate fuel oil if it has been exposed to high temperatures during engine operation?

A) To reduce the fuel’s thermal expansion and prevent pressure buildup in storage tanks

5. Which first aid measure is recommended for treating inhalation exposure to distillate fuel oil according to the MSDS?

B) Move the person to an area with fresh air and seek medical advice

3. What engine performance issue can arise from water contamination in distillate fuel oil?

B) Misfiring and rough engine operation

3. What example of hazard information might be listed in the "Health Hazards Identification" section of an MSDS for distillate fuel oil?

B) Precautions to avoid skin contact and inhalation

4. What is a key feature of the closed cup method for determining the flashpoint of bunker fuel?

B) The test is conducted in a sealed container to minimize vapor loss

2. What is one common treatment process applied to distillate fuel oil before it is used in engines?

A) Filtration to remove particulate matter and sediment

1. Why might distillate fuel oil need cooling after it exits the engine?

B) To prevent overheating and potential damage to downstream components

2. What type of extinguishing media is recommended in the "Fire-Fighting Measures" section of the MSDS for distillate fuel oil?

B) Dry chemical powder or carbon dioxide (CO2)

2. In a typical distillate fuel supply system, what is the purpose of a fuel oil transfer pump?

B) To transfer fuel from the storage tank to the day tank or engine

How can potential problems associated with wax in distillate fuel be avoided?

B) By storing the fuel at temperatures above the cloud point

How can fuel system and engine-related problems caused by sodium contamination be avoided?

A) Regularly monitor and control sodium levels in the fuel

5. Which product from the distillation of crude oil is used for lubrication of machinery and engines on board a vessel?

C) Lubricating Oil

2. What is a common reason for cooling distillate fuel oil after it leaves the engine but before it reaches storage or further use?

A) To prevent the formation of deposits and waxes in the fuel

With reference to diesel engine fuel, which of the following are potential problems that can occur if the fuel is contaminated with microbes?

B) Clogging of fuel filters and increased wear on engine components

1. What problem can microbes in distillate fuel oil cause in the fuel system?

B) Formation of sludge and growth of microbial biomass

1. What is a common problem caused by water contamination in distillate fuel oil?

B) Corrosion and rusting of fuel system components

According to ISO 8217, how are aluminium and silicon oxides typically removed from marine fuel oil?

A) By using a centrifuge to separate solid particles from the fuel

1 / 83

MDE Unit 10 lubricating oil

How can problems with inadequate oil flow or circulation in a gearbox be remedied? (Select THREE)

A) Regularly inspect and clean the oil filters, C) Increase the oil level to the recommended amount, E) Replace worn or damaged oil pumps

Question 5:

Why is it important for lubricating oil to have a high oxidation resistance?

A) To prevent oil degradation and maintain performance over time

1. What are the potential effects of excessive lubrication in a diesel engine?

C) Increased risk of oil foaming: Which can lead to reduced lubrication efficiency and potential engine damage.

Question: Which of the following are indications that lubricating oil is suffering from microbial degradation? (Select FOUR)

A) Presence of sludge in the oil, B) Unusual or foul odor from the oil, C) Increase in oil viscosity, D) Discoloration of the oil

5. Which contaminant is typically associated with high levels of silicon in diesel engine lubricating oil?

B) Increased wear from abrasive particles

4. What is the primary concern with high levels of water contamination in diesel engine lubricating oil?

B) Promotes corrosion and rust formation on engine components

5. Which lubrication method is typically used in medium-speed diesel engines to ensure consistent oil delivery and cooling?

B) Forced circulation lubrication

Question 2: Which of the following contaminants is most likely to enter diesel engine lubricating oil due to wear and tear of engine components?

B) Metallic particles

1. Which of the following contaminants in diesel engine lubricating oil can lead to increased wear on engine components?

A) Water, C) Silicon

Question 4: Which of the following is a recommended action to prevent the oxidation of diesel engine lubricating oil?

B) Keeping the oil free from moisture

1. What is ONE disadvantage of using grease as a lubricant in a plain bearing?

A) Grease can become less effective at high temperatures compared to oil.

4. In forced circulation lubrication systems, how is oil delivered to the cylinder liners?

B) By a mechanical pump that circulates oil through the engine

2. What effect does the presence of fuel dilution in diesel engine lubricating oil typically have?

C) Leads to increased oil consumption and potential for engine damage

How can problems with excessive friction due to worn or misaligned gears in a gearbox be remedied? (Select TWO)

A) Replace worn or damaged gears, C) Adjust or realign misaligned gears

3. What is the primary advantage of forced circulation lubrication over splash lubrication in medium-speed diesel engines?

B) Ensures more uniform oil distribution and control of oil flow

Question 1: What is one of the most effective methods for maintaining the condition of diesel engine lubricating oil?

C) Maintaining proper oil temperature

Question 3: Which factor is a primary contributor to fuel dilution in diesel engine lubricating oil during service?

A) Prolonged idling of the engine

Why are large quantities of lubricating oil used in a gearbox?

A) To ensure adequate cooling and prevent overheating of gearbox components

1. Which of the following is a common method for lubricating cylinder liners in medium-speed diesel engines?

B) Forced circulation lubrication

1. Which of the following are functions of lubricating oil in a diesel engine? (Select FOUR)

A) Reduces friction between moving parts, B) Acts as a coolant to lower engine temperatures, C) Cleans the engine by removing contaminants, F) Prevents corrosion and rust on engine parts

Question 5: What role does maintaining proper oil levels play in keeping diesel engine lubricating oil in a satisfactory condition?

C) It ensures adequate lubrication of engine components.

Which property of lubricating oil is crucial for preventing metal-to-metal contact between engine components?

A) Viscosity

3. How does the presence of soot in diesel engine lubricating oil affect engine performance?

B) Increases the risk of abrasive wear and reduces oil life

1. What are the potential effects of insufficient lubrication in a diesel engine?

A) Increased friction and wear: Leads to overheating and premature component failure.

Question 2: Which of the following practices is essential for preventing contamination of diesel engine lubricating oil?

B) Regular oil analysis and monitoring

Question 2:

Why is a high flash point important for lubricating oil used in diesel engines?

A) To prevent premature ignition and reduce fire risk

Which of the following are possible causes of excessive lubricating oil temperature in a gearbox when operating at normal speeds? (Select FOUR)

A) Inadequate oil flow or circulation, B) Excessive friction due to worn or misaligned gears, C) High ambient temperature, E) Insufficient oil level

1. What is ONE advantage of using grease as a lubricant in a plain bearing?

A) Grease provides continuous lubrication without the need for external oil supplies.

How can problems with high ambient temperature affecting a gearbox be remedied? (Select THREE)

A) Improve ventilation or cooling systems around the gearbox, B) Use high-temperature resistant lubricants, D) Reduce the gearbox's operational speed

Question: Upon detecting the early signs of microbial degradation in the main engine lubricating oil, which TWO actions should be taken?

B) Add a biocide to the lubricating oil, D) Monitor the oil condition more frequently

Question 3: How can the accumulation of sludge and deposits in diesel engine lubricating oil be minimized?

B) Ensuring proper filtration and regular filter changes

Question 3:

What does a low pour point in lubricating oil signify?

A) The oil remains fluid and pumpable at low temperatures

1. What are the main functions of diesel engine lubricating oil? (Select all that apply)

A) Reduces friction between engine components, C) Cools engine components by carrying away heat, D) Cleans engine parts by suspending contaminants, F) Protects engine parts from corrosion and rust

Question 4: How might microbial contamination occur in diesel engine lubricating oil during service on a marine vessel?

C) Presence of water in the oil

Question 1: What is a common cause of water contamination in diesel engine lubricating oil during service on a marine vessel?

B) Condensation of water vapor

How can problems with insufficient oil level in a gearbox be remedied? (Select TWO)

A) Add oil to the gearbox until it reaches the recommended level, D) Regularly check and maintain the oil level

1. What does hydrostatic lubrication refer to in engine lubrication systems?

A) A method where oil is forced under pressure between surfaces to create a lubricating film, eliminating metal-to-metal contact.

1. What does boundary lubrication refer to in lubrication systems?

B) A lubrication condition where the lubricant film is so thin that surfaces make intermittent contact, and additives in the oil help reduce wear.

2. How does splash lubrication work for cylinder liners in medium-speed diesel engines?

B) Oil is splashed onto the cylinder liners by the movement of engine components

Question 4:

Which property of lubricating oil is important for neutralizing acids formed during combustion?

B) Total Base Number (TBN)

1 / 40

MDE Unit 11 oil filters

What is a common cause of oil losses in a centrifugal separator?

C) Incomplete separation of contaminants

Question 2: How does a coalescer filter separate water from distillate fuel oil?

C) By using a series of filter media that cause small water droplets to merge into larger droplets, which are then easily separated.

Question 2:

What is the main component in a centrifugal lubricating oil filter that creates the necessary centrifugal force?

B) A rotating bowl or rotor

Which of the following is a common cause of water contamination in diesel engine lubricating oil?

C) A leaking cylinder head gasket

Which of the following factors influence the efficiency of a centrifugal separator in a diesel engine's lubrication system?

A) Rotor speed, oil temperature, viscosity of the oil, and the amount of contaminants present

Question 3:

How can the presence of water in the lubricating oil be detected on board a vessel?

B) By conducting a crackle test

How can temperature control contribute to minimizing oil losses in a separator?

A) By maintaining the oil within an optimal temperature range to prevent degradation

Question 5:

Which onboard test can be used to assess the viscosity of lubricating oil in a medium-speed diesel engine?

B) Viscometer test

Why is it important to use the correct type of oil for a specific separator?

B) To match the oil viscosity with the separator’s operational requirements

Question 1: What is the primary function of a coalescer type distillate fuel oil filter?

B) To separate water from fuel by causing small water droplets to combine into larger droplets.

Question 5:

What happens to the clean oil after it passes through a centrifugal lubricating oil filter?

A) It is returned directly to the engine's lubrication system

How does water in engine oil affect the oil's lubricating properties?

B) It causes the oil to lose its ability to lubricate effectively

Question: Which of the following best explains the principle of operation of a coalescer lubricating oil filter?

D) The filter causes small droplets of water or other liquids to merge into larger droplets, which are then separated from the oil.

What maintenance practice can help prevent water contamination in the engine lubricating oil?

B) Ensuring proper engine warm-up before operation

Which operational practice can help reduce oil carryover in a centrifugal separator?

B) Regularly monitoring and adjusting the separator’s speed

Which factor primarily influences the discharge frequency of an engine lubricating oil purifier?

B) The level of contaminants in the oil

Question 3: What happens to the larger water droplets formed in a coalescer type filter?

B) They are collected in a water separator and drained off.

Question 4:

Which of the following best describes the process by which a centrifugal filter operates?

C) Oil is spun at high speed to separate contaminants based on density

What is one effective method to minimize oil losses due to incomplete separation in a centrifugal separator?

C) Regularly cleaning and maintaining the separator

Question 2:

What is the purpose of conducting a blotter spot test on lubricating oil on board?

C) To detect the presence of contaminants such as soot and water

Which of the following is a common cause of water contamination in diesel engine lubricating oil?

C) A leaking cylinder head gasket

What effect does high operational speed have on oil losses in a centrifugal separator?

B) It increases the likelihood of oil carryover

How does the capacity of the oil purifier affect its discharge frequency?

A) A larger capacity purifier will have a lower discharge frequency

How does the type of contaminants in the oil influence the discharge frequency of the purifier?

A) Different types of contaminants require a different discharge frequency

Question 3:

In a centrifugal type lubricating oil filter, how are the contaminants typically collected and separated from the oil?

B) They are collected on the inner wall of the rotating bowl

Which operational issue can result in oil carryover in a centrifugal separator?

B) Inadequate maintenance of the separator

Question 4:

Which of the following actions can prevent the deterioration of lubricating oil in a large medium-speed diesel engine?

B) Regularly replacing the oil filters

Question 3:

How is the condition of lubricating oil in a large medium-speed diesel engine typically monitored?

B) By regularly testing the oil's viscosity, water content, and acid number

How can water in engine oil impact engine performance?

B) It can lead to engine knocking and reduced performance

Which component failure is likely to introduce water into the engine lubricating oil?

C) A damaged water pump

What is one of the primary effects of water contamination in engine oil?

B) Increased oil viscosity

How can water ingress through the engine’s cooling system affect the lubricating oil?

B) It can cause the oil to become foamy

Question 2:

What is the main purpose of using a centrifugal separator in a large medium-speed diesel engine's lubricating oil system?

B) To remove water and particulate contaminants from the oil

Which of the following is a potential consequence of water contamination in engine oil on engine components?

B) Enhanced corrosion of engine parts

Question 1:

Which of the following is the primary function of a centrifugal type lubricating oil filter in a diesel engine?

C) To remove contaminants from the oil by using centrifugal force

Question 1:

Which of the following methods is commonly used on board to assess the condition of lubricating oil in a large medium-speed diesel engine?

C) Onboard testing for water content and acid number

Question 4:

Why is it important to regularly measure the Total Base Number (TBN) of lubricating oil on board?

B) To assess the oil’s ability to neutralize acids

What problem can water in engine oil cause in terms of oil circulation?

D) It can reduce oil flow through the engine

Why might oil losses occur due to operational temperature issues in a separator?

B) Because high temperatures can cause oil degradation and carryover

Question: Which of the following best explains the principle of operation of a magnetic lubricating oil filter?

B) The filter employs a magnetic field to attract and remove ferrous particles from the oil.

Question: Which of the following best explains the principle of operation of a plate edge (e.g., Auto-Klean) lubricating oil filter?

B) The filter uses a series of closely spaced metal plates to trap and remove solid particles from the oil as it passes through.

Question 4: Which of the following is a key advantage of using a coalescer type filter in a distillate fuel oil system?

B) It is capable of removing both solid and water contaminants simultaneously.

Question 1:

Which of the following practices is essential to maintain the lubricating oil in optimum condition in a large medium-speed diesel engine?

B) Periodically cleaning the oil using a centrifugal separator

How can seal and joint failures contribute to oil losses in a separator?

B) By allowing oil to escape through leaks

Question: Which of the following best explains the principle of operation of a centrifugal lubricating oil filter?

C) The filter uses centrifugal force to separate contaminants from the oil.

Which factor regarding oil condition affects the discharge frequency of a lubricating oil purifier?

D) The oil’s contamination level

How can condensation in the engine contribute to water contamination of the lubricating oil?

C) It occurs when the engine is not run at high enough temperatures

How can ensuring proper sealing and joint integrity help in minimizing oil losses in a separator?

A) By preventing oil leakage through seal and joint failures

What role does the oil flow rate play in determining the discharge frequency of a lubricating oil purifier?

B) A higher flow rate results in higher discharge frequency

1 / 49

MDE Unit 12 heat exchangers

Question:

State THREE advantages of plate-type heat exchangers compared to tube-type heat exchangers.

A) Higher heat transfer efficiency, smaller footprint, and easier maintenance

Question 5:

Which component in a plate-type heat exchanger directs the flow of fluids and ensures proper distribution across the plates?

D) The distribution ports

Question 1:

Which of the following is a key component of a plate-type heat exchanger?

B) Gasketed plates

Question 2:

In a plate-type heat exchanger, how are the plates typically arranged?

A) Stacked horizontally with alternating flow channels

Question 2:

What is the primary function of the gaskets or seals in a plate-type heat exchanger?

B) To ensure the fluids do not mix and to prevent leakage

Question 3:

What is the primary purpose of gaskets in a plate-type heat exchanger?

D) To maintain the structural integrity of the plates

Question 4:

What is the purpose of the flow distribution plates in a plate-type heat exchanger?

A) To direct the fluid evenly across the entire plate surface

Question:

With reference to plate-type heat exchangers, what is the purpose of the plates being corrugated?

B) To increase the surface area for heat transfer

Question 3:

In a plate-type heat exchanger, where are the fluid inlet and outlet connections typically located?

A) On the sides of the heat exchanger

Question:

With reference to plate-type heat exchangers, which materials are commonly used for the plates and seals?

C) Plates: Stainless steel; Seals: Nitrile rubber

Question 4:

In a typical plate-type heat exchanger, what is the common flow configuration?

C) Counter-current flow

Question 1:

In a plate-type heat exchanger, how are the plates arranged to facilitate heat transfer?

B) Plates are arranged in a single stack with alternating flow channels

Question 5:

Which component in a plate-type heat exchanger helps to maintain the spacing between the plates?

B) The bolts and frame

Question:

With reference to plate-type heat exchangers, what is the purpose of tell-tales?

B) To provide an early warning of seal failure

1 / 14

MDE Unit 13 cooling systems

Question 5:

In a keel type cooling water system, which component ensures that the engine's freshwater cooling circuit is effectively isolated from the seawater system?

A) Heat Exchanger

Question 1:

Which of the following is a key condition for the effectiveness of a fresh water cooling system treatment program?

A) Periodic chemical analysis and adjustment of treatment levels

Question 3:

What does a high temperature drop across the water cooler indicate?

C) Effective heat removal by the cooler

Question 1:

What could be a cause of decreased performance in a diesel engine water cooler?

B) Clogged or fouled cooling passages

What is the primary function of the inhibitor used in fresh water cooling treatment?

B) To prevent the formation of scale and corrosion

Question 4:

What is the primary purpose of the seawater strainer in a keel type cooling water system?

A) To filter and remove debris from seawater

Question 2:

In a keel type cooling water system, which component is used to pump seawater through the keel cooler?

B) Centrifugal Pump

Question 1:

What is the primary purpose of the heat exchanger in a typical diesel engine cooling water system?

C) To transfer heat from the engine coolant to the external cooling medium

Question 4:

To maintain an effective fresh water cooling system treatment program, it is important to:

A) Regularly clean the system to prevent buildup of contaminants

Question 1:

Which of the following is the main component of a keel type cooling water system that helps to dissipate heat from the engine?

B) Keel Cooler

Question 5:

What is the purpose of the cooling water pump in a diesel engine cooling water system?

C) To ensure the circulation of cooling water through the engine and heat exchanger

Question 4:

How can an airlock in the cooling system affect the performance of a diesel engine water cooler?

C) It can cause localized overheating and reduced cooling efficiency

Question 2:

What is the function of the header tank in a diesel engine cooling water system?

B) To allow for expansion and contraction of the coolant

Question 2:

What is a necessary condition for ensuring proper treatment of a fresh water cooling system?

A) Regular monitoring and maintenance of the system’s temperature

Question:

With reference to main engine cooling water systems, what type of pumps are typically used, and why?

A) Centrifugal pumps - They are preferred for their ability to handle large volumes of water and maintain a steady flow rate with minimal pulsation.

Question 3:

What impact does a malfunctioning thermostat have on the performance of a diesel engine water cooler?

C) Decreases the effectiveness of temperature regulation

Question 5:

What is the impact of low coolant flow rate on the performance of a diesel engine water cooler?

D) Increased coolant temperature at the cooler outlet

Question:

With reference to main engine cooling water systems, what is the primary purpose of the header tank?

B) To provide a reservoir for excess coolant and maintain system pressure

Question 4:

Which parameter is essential for evaluating the efficiency of a diesel engine water cooler, in addition to temperature difference?

B) The pressure drop across the cooler

Question 3:

Which condition contributes to the effectiveness of a fresh water cooling system treatment program?

A) Ensuring the use of treatment chemicals that are compatible with the system

Question 3:

Why are circulation pumps used in a diesel engine cooling water system?

C) To maintain a constant flow of coolant through the engine and heat exchanger

Question:

Which of the following safety considerations is most important when handling inhibitors used in cooling systems?

A) Wearing personal protective equipment (PPE) such as gloves and goggles

Question 4:

What is the role of the thermostat in a diesel engine cooling water system?

A) To regulate the coolant flow based on temperature

Question 1:

How is the performance of a diesel engine water cooler typically measured?

C) By the temperature difference between the inlet and outlet water

Question 2:

Which instrument is commonly used to measure the temperature difference across a diesel engine water cooler?

D) Thermocouple or temperature sensor

Question 2:

Which condition might result in a water cooler showing a higher-than-normal temperature difference across its inlets and outlets?

C) Blocked cooling water passages

Question 3:

Which component of the keel type cooling water system is used to manage the pressure and temperature of the coolant?

A) Expansion Tank

Question 5:

Which maintenance issue could cause a water cooler to exhibit higher pressure drops and reduced performance?

B) Fouled or dirty cooler surfaces

Question:

With reference to main engine cooling water systems, why might both heaters and coolers be fitted?

A) To adjust the coolant temperature to match the engine's operational requirements and prevent freezing or overheating

1 / 29

MDE Unit 14 start systems

Question 6:

Which component prevents the starter motor from operating when the engine is already running?

D) Starter inhibitor switch

Question 2:
During which stroke of a four-stroke diesel engine cycle is the air start valve usually open?

B) Compression stroke

Question 4:
What is the significance of the crank angle at which the air start valve closes on a four-stroke diesel engine?

B) It prevents the backflow of exhaust gases into the starting air system

Question 2:

Which of the following components is typically included in a diesel engine hydraulic oil start system?

A) Hydraulic pump

Question 3: During an attempt to start a large marine diesel engine, you find that no air is being delivered to the cylinders. What could be a likely cause?

C. Closed starting air supply valve.

Question 2:
What is the function of the starting air interlock in a direct air start medium-speed diesel engine?

C) To prevent starting if the main starting air valve is not fully open

Question 1:
What is the primary purpose of regularly checking the air pressure in the air motor starting system?

A) To ensure the air motor operates at the correct speed

Question 4:
What is a common sign that the air motor’s exhaust port needs to be inspected or cleaned?

A) Reduced engine starting speed

Question 4: What should be inspected if there is air leakage during the start sequence of a marine diesel engine?

B. Starting air valve condition.

Question 1:
At what approximate crank angle does the air start valve typically begin to open on a four-stroke diesel engine during the starting process?

A) 0° (TDC)

Question 2:

Which component of the electric starting system provides the electrical power needed to turn the starter motor?

C) Battery

Question 4:
Which safety device in the air starting system is responsible for releasing excess air to the atmosphere in case of an overpressure condition?

A) Safety valve

Question 1: When initiating the start sequence on a large medium-speed marine diesel engine with individual air starting valves, the engine fails to start. Which of the following is the first check you should perform?

B. Check if the main starting air receiver is pressurized.

Question 1:

What is the primary function of the solenoid in a solenoid-operated, battery-powered electric starting system?

B) To engage the starter motor with the engine’s flywheel

Question 2: If an engine does not start when initiating the start sequence, and the air start lever is in the correct position, what should be the next step?

A. Check for leaks in the starting air system.

Question 3:
In an air starting system, the interlock system is designed to:

A) Ensure that the engine cannot be started unless the turning gear is disengaged

Question 1:
Which of the following interlocks is most commonly fitted to a direct air start medium-speed diesel engine to prevent the engine from starting if the turning gear is engaged?

B) Turning gear engagement interlock

Question 4:

Which of the following describes the role of the starter motor in the electric starting system?

C) To crank the engine and initiate combustion

Question 5: Which of the following could cause a failure to start in a large marine diesel engine due to an issue with the air starting system?

A. Air start valve stuck in the open position.

Question 7:

What is the purpose of the starter relay in an electric starting system?

C) To amplify the current to the starter motor

Question 3:
How does the timing of the air start valve's opening relate to the inlet and exhaust valves' operation in a four-stroke diesel engine?

A) The air start valve opens when both inlet and exhaust valves are closed

Question 4:

What role does the hydraulic accumulator play in the hydraulic oil start system of a diesel engine?

C) It maintains hydraulic pressure for starting the engine

Question 5:

Which safety interlock prevents the hydraulic oil start system from operating if certain conditions are not met?

A) Hydraulic pressure switch

Question 3:

How is the solenoid activated in a solenoid-operated starting system?

D) By a current flowing through its coil

Question 1:

What is the primary function of the hydraulic oil start system in a diesel engine?

C) To initiate the engine’s start-up by engaging the starting mechanism

Question 3:
Which interlock prevents a medium-speed diesel engine from being started if the engine's crankcase doors are open?

B) Crankcase door interlock

Question 3:
Why is it important to inspect the condition of the air motor’s drive gear during routine maintenance?

B) To ensure the gear is properly aligned with the engine's flywheel

Question 3:

Which interlock is commonly found in a diesel engine hydraulic oil start system to ensure safe operation?

B) Hydraulic fluid level sensor

Question 1:
Which of the following is a safety device commonly fitted to the air starting system of a large medium-speed marine diesel engine?

A) Pressure relief valve

Question 6:

In a hydraulic oil start system, what is the purpose of the hydraulic control valve?

A) To regulate the flow of hydraulic fluid to the starting motor

Question 5:

What happens when the starter switch is turned on in a solenoid-operated starting system?

B) The solenoid engages the starter motor and the engine cranks

Question 2:
Which of the following is a key maintenance task for the air motor to prevent corrosion and ensure long-term reliability?

A) Lubricating the air motor components regularly

Question 5:
During a routine check, what should be done if moisture is found in the air motor's air supply line?

B) Drain the moisture and inspect the air dryer or moisture separator

Question 2:
What is the primary function of the non-return valve in the air starting system of a medium-speed marine diesel engine?

A) To prevent backflow of air into the receiver

Question 4:
The low lube oil pressure interlock in a direct air start medium-speed diesel engine is designed to:

B) Prevent starting if lube oil pressure is below a safe threshold

1 / 35

MDE Unit 15 piston cylinder liners

Question 4:

What is the purpose of removing the fuel injectors before removing a cylinder head on a four-stroke diesel engine?

C) To relieve pressure within the combustion chamber

Question 1:

What is the first step in the procedure for renewing a bottom end bearing on a diesel engine?

B) Draining the engine oil and coolant

Question 2:

What should be done if the piston’s ring grooves show excessive wear during inspection?

C) Replace the piston and rings together

Question 4:

Why is it important to check for any unusual noises during the initial startup of an engine with a new liner?

B) To detect any potential misalignment or improper fitting of components

Question 5:

What fault in a piston pin can cause operational issues in a diesel engine?

B) Excessive clearance or wear

Question 5:

What is the significance of checking the piston for signs of piston ring land deformation during inspection?

B) To verify the piston’s ability to maintain proper compression

Question 1:

What is the first precaution to take before starting an engine for the first time after maintenance?

B) Verify all bolts and fasteners are properly tightened

Question 2:

Why is it important to ensure that the engine has adequate oil pressure before starting it for the first time?

C) To protect the engine from damage

Question 6:

What should be checked and adjusted if necessary during the initial startup of an engine with a new liner?

B) Fuel injection timing

Question 5:

What is a common method to check for warping or distortion in a cylinder liner during calibration?

B) Use a dial gauge to measure any deviations from the cylindrical shape

Question 5:

What should be done immediately after unbolting the cylinder head on a four-stroke diesel engine?

A) Tap the cylinder head lightly to break the seal

Question 3:

What should be checked regarding the cooling system before an initial engine startup?

A) Ensure the coolant is at the correct level

Question 4:

During inspection, if the piston shows signs of excessive carbon build-up, what should be the next step?

B) Use a chemical carbon remover to clean the piston

Question 1:

What is the first step to take when preparing to remove a four-stroke diesel engine cylinder head?

D) Release stored energy, including air and hydraulic pressures

5. Why is it important to mark the location of each cylinder head bolt during removal?

B) To prevent mixing up the bolts during reassembly.

Question 4:

What precaution should be taken with the electrical system before starting the engine?

B) Inspect all wiring connections

Question 3:

Which tool is commonly used to measure the wear of the cylinder liner?

D) Bore gauge

Question 2:

What is a common sign of piston ring wear that can be observed during inspection?

B) Excessive oil consumption

Question 4:

What should be done if scoring is found on the cylinder liner during inspection?

C) Replace the cylinder liner or recondition it

Question 7:

What is a common tool used to measure the clearance between the new bottom end bearings and the crankshaft?

C) Feeler gauge

Question 2:
Why is it essential to relieve the cylinder pressure before removing the cylinder head of a four-stroke diesel engine?

B) To avoid accidental ejection of the head

Question 3:

What should be checked if the inner diameter of the cylinder liner is found to be out of tolerance during calibration?

B) Recheck the measurement for accuracy

2. What is the primary reason for ensuring the engine is cooled down before removing the cylinder head?

A) To prevent distortion of the cylinder head.

4. What should be done with the coolant before removing the cylinder head?

B) Drain the coolant to prevent it from spilling into the cylinders.

Question 3:

Which of the following should be done after releasing stored energy and locking the engine turning gear, but before unbolting the cylinder head?

B) Drain the cooling system

Question 5:

What is a recommended practice for the first engine oil change after installing a new cylinder liner?

B) Wait until the engine has run for a specified number of hours before changing the oil

Question 3:

How should the piston’s skirt be inspected to check for ovality or distortion?

A) Use a micrometer to measure the diameter at various points

Question 3:

If a cylinder liner shows signs of excessive taper, what does this indicate?

C) Uneven wear due to poor lubrication

1. Which of the following is the first step in preparing to remove a diesel engine cylinder head?

D) Secure all necessary permits and ensure the engine is properly isolated.

3. Which safety precaution is most critical when handling the cylinder head removal?

B) Wear appropriate personal protective equipment (PPE).

Question 2:

What is a typical fault observed on a piston that might indicate engine problems?

B) Worn piston rings

Question 3:

Which type of lubrication is critical to verify before starting an engine with a new cylinder liner?

C) Engine oil lubrication

Question 7:

What should be done if the engine does not start or exhibits abnormal behavior during the initial startup?

B) Shut down the engine and perform a thorough check

Question 4:
Before removing a cylinder head on a four-stroke diesel engine, why should the cooling system be drained?

C) To avoid leakage into the combustion chamber

Question 2:

During the initial startup of an engine with a new liner, what is important to check frequently?

D) Oil pressure and temperature

Question 6:

What is a common procedure to check the piston for proper fit in the cylinder liner?

B) Check piston for free play in the liner

Question 4:

Which calibration technique is used to measure the wall thickness of a cylinder liner?

A) Using a micrometer to measure the outer and inner diameters

Question 2:

When measuring the outer diameter of a cylinder liner for calibration, which tool is most appropriate?

B) Micrometer

Question 7:

What should be examined on the piston pins during inspection?

B) Wear and clearance

Question 6:

What should be done if there is a significant amount of debris or metal particles found in the oil pan during the bearing replacement process?

B) Clean the debris from the oil pan and replace the oil filter

Question 4:

What is an important consideration when installing new bottom end bearings?

B) Using the correct torque specifications for the bearing caps

Question 6:

During initial startup, why is it important to monitor the engine for unusual noises or vibrations?

B) To ensure the engine runs smoothly

Question 1:

When inspecting a removed diesel engine piston, what is the primary purpose of checking the piston for scoring or scratches?

B) To assess if the piston has been damaged by foreign objects

Question 2:

Why is it necessary to lock the engine turning gear before removing a cylinder head?

B) To prevent the crankshaft from rotating

Question 5:

During the inspection of the piston, what should be checked for proper condition?

A) Piston skirts

Question 1:

When inspecting a cylinder liner after removing the piston, which of the following should be checked for wear or damage?

B) Cylinder liner surface

Question 7:

What is a potential fault to look for on a piston during inspection that may affect engine compression?

B) Worn piston rings or ring lands

Question 3:

When replacing the bottom end bearings, what should be checked before installing the new bearings?

A) The condition of the crankshaft journals

Question 6:

What fault might be detected in a cylinder liner that suggests coolant leakage?

C) Darkened oil with a milky appearance

Question 1:

What is the first step in calibrating a removed diesel engine cylinder liner?

C) Clean the liner thoroughly

Question 1:
Which of the following is the first safety precaution to take before removing a four-stroke diesel engine cylinder head?

C) Release all stored energy, including air and hydraulic pressures

Question 4:

During piston inspection, what fault might be indicated by scoring on the piston skirts?

B) Insufficient oil supply

Question 5:

After replacing the bottom end bearings, what is a key step before starting the engine?

A) Refilling the engine oil and coolant

Question 1:

Which of the following is a common fault that can be found on a cylinder liner during inspection?

B) Cylinder liner scoring or scratches

Question 1:

What is the primary precaution to take during the initial startup of an engine with a new cylinder liner to ensure proper seating?

A) Increase the engine speed gradually

Question 3:
What is the purpose of locking the engine turning gear before removing a cylinder head?

A) To prevent the crankshaft from rotating

Question 5:

Before starting an engine for the first time after maintenance, why is it important to check the oil level and quality?

B) To ensure proper lubrication and performance

Question 2:

Which component must be removed to access the bottom end bearings of a diesel engine?

A) The oil pan

Question 5:
Which of the following safety equipment is recommended when removing a cylinder head from a four-stroke diesel engine?

C) Safety goggles and a hard hat

Question 6:

If a cylinder liner is found to be out of specification after calibration, what is a typical corrective action?

C) Refurbish or replace the liner

1 / 60

MDE Unit 16 engine faults

Question 4:

What should be checked if low lubricating oil pressure is suspected due to oil level issues?

B) Oil level in the engine

Question 1: What is the first action that should be taken if a high bearing temperature is detected in a diesel engine during operation?

C) Reduce engine speed and load to minimize heat generation

Question: How can a leaking cylinder air start valve be detected while the engine is running?

D) By monitoring for a hissing sound near the air start valve manifold

Question 3:

What is a critical step in preparing the fuel system of a main propulsion engine before going to sea?

C. Purging air from the fuel lines to prevent engine misfires

Question 4:
How can you minimize abnormal turbocharger vibration caused by shaft misalignment?

B) By regularly checking and adjusting the shaft alignment

Question 4:
How does a fluid coupling protect the marine engine from shock loads?

B) By absorbing and dissipating energy through the fluid, reducing stress on the engine

Question:
Which of the following are possible causes for white smoke in marine diesel engines? (Select TWO)

A. Water in the fuel, E. Cold starting of the engine

Which of the following are possible causes for black smoke in marine diesel engines? (Select TWO)

A. Excessive fuel injection, B. Insufficient air supply

Question 4: After stopping the engine due to high bearing temperature, what is a critical check that should be performed before restarting?

B) Inspect the bearing for signs of overheating or damage

Question:
Which of the following is an effective remedy for excessive fuel injection in marine diesel engines?

D. Reduce the fuel pump delivery rate

Question 6:

What could be a mechanical cause of unstable engine speed, and how can it be fixed?

A) Worn camshaft; replace the camshaft

Question 2: After shutting down the engine due to a leaking air start valve, what should be done next?

B) Inspect the valve and seating area for damage or debris

Question 7:

If an engine is overheating due to a failing radiator fan, what should be the corrective action?

B) Repair or replace the radiator fan

Question 2:
What immediate action should be taken if the air start pipework is becoming extremely hot?

C. Check for and clear any obstructions in the pipework

Question 7:

If unstable engine speed is caused by a malfunctioning governor, what is the recommended solution?

C) Replace the governor

Question:
Which of the following is an effective remedy for the burning of lubricating oil in marine diesel engines?

A. Replace worn piston rings

Question 3:

Which of the following is a potential reason for fluctuating oil levels in the main engine sump during operation?

C. Variations in engine load

Question 3:
Which maintenance practice can help minimize the chances of turbocharger vibration?

B) Regularly cleaning the turbine and compressor wheels

Question 4:

Which condition may lead to a cylinder air start valve leak?

B) Corrosion or pitting of the valve components

Question 5:

Before leaving port, why is it important to conduct a test run of the main propulsion engine?

B. To ensure that all systems are operating correctly and respond as expected

Question 2:

If a diesel engine is experiencing unstable speed due to air intake issues, what is the most likely cause?

B) Dirty or blocked air filter

Question 1:

Which of the following could cause a sudden drop in the oil level of a main engine sump?

A. Oil leakage from a defective gasket or seal

Question 5:

If low lubricating oil pressure is caused by excessive oil viscosity, what is the recommended action?

B) Change the oil to a lower viscosity grade

Question 3:

What could be a potential cause of a leaking cylinder air start valve?

B) Debris lodged in the valve seat

Question 3:

What is a potential cause of unstable engine speed related to the engine's electronic control system?

B) Faulty engine control unit (ECU)

Question 1:

Which of the following is a possible cause of knocking noise in a diesel engine during operation?

A. Incorrect fuel injection timing

Question 4:
What might cause abnormal turbocharger vibration at a steady speed in a diesel engine?

B) Worn bearings in the turbocharger

Question 5:
To reduce the likelihood of abnormal turbocharger vibration, which of the following should be done during routine maintenance?

B) Inspect for and promptly replace damaged or loose turbine blades

Question 1:
What is a potential consequence of the air start pipework becoming extremely hot?

B. Damage to the pipework or surrounding components

Which of the following are possible causes for blue smoke in marine diesel engines? (Select TWO)

B. Burning of lubricating oil, D. Worn piston rings

Question 1:
What is a potential cause of abnormal turbocharger vibration at a steady speed in a diesel engine?

B) Loose or damaged turbine blades

Question 1:

Which of the following is a common cause of a leaking cylinder air start valve?

B) Worn or damaged valve seating

Question 5:

Which of the following scenarios could lead to a false high oil level reading in the main engine sump?

C. Improperly seated dipstick

Question 4:

A diesel engine is producing a thumping noise during operation. Which of the following is a probable cause?

A. Broken engine mounts

Question 4:

How can issues with the fuel supply system lead to unstable engine speed, and what is the appropriate remedy?

A) Fuel contamination; replace the fuel filter

Question 2:

What might cause the oil level in a main engine sump to rise unexpectedly?

A. Water contamination in the oil

Question 4: A possible cause of high bearing temperatures due to operational issues could be:

C) Overloading the engine beyond its design capacity

Question 2: What could be a reason for high bearing temperatures in a diesel engine due to issues with the lubricating oil?

A) Low oil viscosity

Question:
With reference to fluid couplings for the main propulsion shaft, how may the transmitted torque be varied?

B) By changing the fluid viscosity in the coupling

Question:
Which of the following is an effective remedy for insufficient air supply in marine diesel engines?

A. Clean or replace the air filters

Question 5:

If unstable engine speed is caused by a problem with the turbocharger, what should be checked?

A) Turbocharger oil supply

Question 1:
Which of the following is an effective way to minimize the risk of abnormal turbocharger vibration in a diesel engine?

B) Ensuring proper alignment of the turbocharger shaft

Question 3:
In a fluid coupling, what role does the impeller play?

A) It acts as the driving component, transmitting power from the engine.

Question 5: Which of the following could cause high bearing temperatures due to maintenance-related issues?

C) Insufficient clearance between the bearing and shaft

Question 2:
Which fluid is most commonly used in a fluid coupling for marine propulsion?

B) Engine oil

Question 1:

What is a common cause of low lubricating oil pressure in a diesel engine?

B) Oil pump failure

Question 3:

What action should be taken if low coolant levels are causing engine overheating?

B) Add coolant to the system

Question 1:

What is a common cause of diesel engine overheating related to the cooling system?

C) Clogged radiator or coolant passages

Question 3: High bearing temperatures in a diesel engine can result from:

C) Contaminated lubricating oil

Question 2:

Which of the following is a remedy for low lubricating oil pressure due to worn engine bearings?

C) Rebuild or replace the engine bearings

Question 3:

Which of the following could cause a whining noise in a diesel engine during operation?

C. Damaged turbocharger

Question 3:
Which safety precaution should be taken when dealing with hot air start pipework?

A. Allow the pipework to cool before handling

Question 2: If high bearing temperature persists after reducing engine load, what should be the next step?

B) Check the lubricating oil flow and pressure

Question 1: Which of the following is a potential cause of high bearing temperatures in a diesel engine?

B) Improper alignment of the bearing

Question:
How can the problem of excessively hot air start pipework on a diesel engine be minimized?

B. Ensure proper insulation of the pipework

Question 4:

How can a malfunctioning water pump lead to overheating, and what is the recommended solution?

B) It can restrict coolant flow; replace the water pump

Question 4:

Which of the following is an important check to perform on the main propulsion system's gearbox before departure?

D. All of the above

Question 6:

What could be the effect of a malfunctioning oil pressure relief valve on oil pressure, and how should it be addressed?

A) It can cause high oil pressure; adjust or replace the relief valve

Question 3:
How can the likelihood of abnormal turbocharger vibration due to bearing wear be minimized?

B. Ensuring adequate lubrication and regular inspection of turbocharger bearings

Question 6:

What could be a consequence of a blocked or restricted air intake on engine temperature, and how can it be fixed?

A) It can cause overheating; clean or replace the air filter

Question:

Which of the following actions can help avoid spurious sump level alarms in a marine diesel engine?

A. Regular calibration and testing of the level sensor

Question 1:

Which of the following checks should be performed on the main propulsion system's lubricating oil system before going to sea?

D. All of the above

Question 1: What is the first step to take upon discovering a leaking cylinder air start valve while the engine is running?

C) Shut down the engine and isolate the affected cylinder

Question 1:
Which of the following is a method to minimize the risk of abnormal turbocharger vibration due to unbalanced rotors?

B. Regularly balancing the turbocharger rotor assembly

Question 3:

How can a blocked oil filter lead to low lubricating oil pressure, and what is the appropriate remedy?

A) It restricts oil flow; replace the oil filter

Question 4:

A decrease in the oil level of a main engine sump over time might indicate which of the following?

A. Oil consumption due to combustion chamber blow-by

Question 2:

Before departure, which of the following actions should be taken to ensure the correct operation of the main engine cooling water system?

D. All of the above

Question 5:
What happens if the fluid level in a fluid coupling is too low?

C) The coupling will slip excessively, reducing power transmission.

Question 1:

What could be a common cause of unstable engine speed related to the fuel system?

B) Malfunctioning fuel injectors

Question 3: If debris is found to be the cause of the air start valve leak, what is the recommended procedure?

B) Clean the valve and seating area, and then reinstall

Question 2:

If a diesel engine is overheating due to a malfunctioning thermostat, what is the appropriate remedy?

B) Replace the thermostat

Question 4: What should be done if the air start valve continues to leak after cleaning and inspection?

B) Replace the air start valve with a new one

Question 2:
What maintenance practice can help prevent abnormal turbocharger vibration caused by fouling?

C. Ensuring regular cleaning of the turbine and compressor blades

Question 2:

What could be a likely cause of a rattling noise coming from the top end of a diesel engine?

A. Loose or worn-out valve lifters

Question 3: Which of the following could be a possible cause of high bearing temperature in a diesel engine?

B) Improper alignment of the bearing

Question:
How can combustion defects in a diesel engine be diagnosed?

B. By inspecting the color of exhaust smoke

Question 4:
What is the most effective way to reduce the risk of abnormal turbocharger vibration caused by misalignment during assembly?

B. Ensuring precision alignment during turbocharger installation

Question 2:
Which of the following could lead to abnormal turbocharger vibration in a diesel engine operating at a steady speed?

C) Misalignment of the turbocharger shaft

Question 2:

Which of the following could cause a cylinder air start valve to leak?

B) Build-up of carbon deposits on the valve

Question 1:
What is the primary function of a fluid coupling in a marine propulsion system?

B) To allow for smooth transmission of power by using fluid dynamics

Question 3:
Abnormal turbocharger vibration while operating at a steady speed could be caused by:

B) Build-up of deposits on the turbine wheel

Question 5:

If a diesel engine is overheating due to excessive engine load, what should be done to remedy the situation?

A) Reduce engine load

Question 5:

What might be the cause of a high-pitched squealing noise in a diesel engine?

A. Loose or worn-out fan belt

Question:
What is a common remedy for improving cold starting of marine diesel engines?

C. Ensure the use of preheaters or glow plugs

Question 2:
To prevent abnormal turbocharger vibration, it is important to regularly:

B) Inspect and replace worn bearings in the turbocharger

Question:
The air start pipework on a diesel engine attached to the cylinder head is becoming extremely hot. What is the most probable cause?

D. Blockage or restriction in the air start pipework

Question 7:

How can a leaking oil line or gasket contribute to low lubricating oil pressure, and what is the appropriate solution?

A) It allows oil to escape; repair or replace the damaged line or gasket

1 / 87

MDE Unit 17 Fluid Couplings

Question:
With reference to fluid couplings, what is the effect of increasing oil flow between the impellors?

C) Enhanced torque transmission and reduced slip

Question 3:
With reference to fluid couplings for the main propulsion shaft, what is an advantage regarding vibration damping?

B) Enhanced vibration damping capability

Question 3:
Which component in a fluid coupling helps to maintain a controlled amount of coupling fluid and manage its flow?

A) Stator

Question 4:
To mitigate the effects of high oil temperature in a fluid coupling system, what action might be taken?

C) Improve the cooling system to manage oil temperature

Question 1:
With reference to fluid couplings, what is a common effect of angular misalignment on the coupling performance?

D) Excessive vibration and potential damage

Question 4:
What is the primary function of the coupling fluid in a fluid coupling?

B) To transfer torque between the engine and the gearbox

Question 3:
What is a likely consequence of angular misalignment in a fluid coupling system in terms of efficiency?

B) Decreased operational efficiency due to uneven torque distribution

Question 1:
With reference to fluid couplings, what is the primary effect of increased oil temperature on the performance of the coupling?

C) Reduced viscosity and potential slippage

Question 2:
In a fluid coupling, what role does the turbine play?

C) To receive fluid flow from the impeller and transmit torque to the gearbox

Question 2:
What is a potential consequence of increased oil temperature in a fluid coupling system?

C) Greater risk of fluid overheating and damage

Question 2:
With reference to fluid couplings for the main propulsion shaft, which of the following is an advantage in terms of engine protection?

C) Automatic slip during overload conditions

Question 1:
Which of the following is a primary component of a fluid coupling used to connect an engine to a gearbox?

B) Impeller

Question 1:
With reference to fluid couplings for the main propulsion shaft, what is one advantage of using a fluid coupling over a mechanical clutch?

B) Smooth torque transmission without shock loads

Question 4:
To correct angular misalignment in a fluid coupling system, what is a recommended action?

B) Adjust the alignment of the shafts to the manufacturer’s specifications

Question 3:
How might increased oil temperature affect the fluid coupling's torque transmission capability?

B) It will decrease torque transmission capability due to reduced fluid viscosity

Question 5:
What is a common feature of the housing in a fluid coupling?

B) It provides a sealed environment for the coupling fluid

Question 2:
How does angular misalignment impact the life expectancy of a fluid coupling?

C) It decreases the life expectancy due to increased wear and tear

1 / 17

MDE Unit 18 friction clutch

Question 4:
How does the design of a friction clutch contribute to vibration damping?

C) By utilizing a combination of friction and damping mechanisms in the clutch assembly

Question 5:
What is the purpose of the clutch cover in a multi-plate friction clutch system?

B) To hold the clutch plates and pressure plate together

Question 1:
Which component in a hydraulically operated, multi-plate friction clutch is responsible for engaging and disengaging the clutch plates?

C) Release bearing

Question 3:
Which component in a friction clutch system helps to minimize torsional vibrations from the engine?

C) Clutch damper springs

Question 5:
Which of the following components is commonly used to damp engine vibrations in a friction clutch system?

A) Flywheel

Question 4:
How does vibration damping in a friction clutch system contribute to driver comfort?

B) By providing smoother gear shifts and reducing engine shudder

Question 2:
What role does the clutch damper play in vibration control?

C) It absorbs and reduces vibrations transmitted through the clutch

Question 6:
Which component in a hydraulically operated, multi-plate friction clutch provides the necessary hydraulic pressure for clutch operation?

C) Hydraulic master cylinder

Question 2:
What is one of the primary functions of a friction clutch in dampening engine vibration?

B) To provide a smooth engagement and disengagement of the engine and gearbox

Question 1:
How is vibration damping typically achieved in an engine connected to a gearbox via a friction clutch?

B) By incorporating a dual-mass flywheel in the clutch assembly

Question 2:
What is the primary function of the hydraulic actuator in a hydraulically operated, multi-plate friction clutch?

C) To apply hydraulic pressure to the release bearing

Question 1:
Why is it important to damp vibration from an engine connected to a gearbox via a friction clutch?

B) To reduce wear and tear on engine and gearbox components

Question 4:
Which part of a hydraulically operated, multi-plate friction clutch is responsible for applying clamping force to the clutch discs?

B) Pressure plate

Question 3:
In a multi-plate friction clutch system, which component transmits the engine torque to the clutch plates?

D) Clutch disc

Question 5:
What is a common feature of a dual-mass flywheel that aids in vibration damping?

B) A spring-loaded mechanism between the two masses

Question 3:
What potential issue can arise if engine vibration is not adequately damped in a system with a friction clutch?

C) Increased risk of mechanical damage to the gearbox and clutch

1 / 16

MDE Unit 19 pneumatic clutch

Question 5:
In the context of a reduction gearing and pneumatic clutch system, which device is used to monitor and protect against abnormal vibration?

A) Vibration sensor

Question:
With reference to pneumatically operated friction clutches, what is the effect of reduced air pressure?

B) Decreased engagement force causing incomplete clutch engagement or slippage

Question 2:
In a pneumatic clutch system, what component is primarily responsible for applying the clamping force to the clutch plates?

B) Pneumatic actuator

Question 1:
With reference to pneumatic clutches used for medium-speed main propulsion purposes, what is the primary function of the pneumatic system in the clutch operation?

B) To engage and disengage the clutch by controlling the air pressure

Question 3:
What is the purpose of a pressure relief valve in the pneumatic clutch system of a propulsion setup?

B) To prevent air pressure build-up

Question 1:
With reference to a reduction gearing and pneumatic clutch arrangement of a propulsion system, which of the following is a protection device typically fitted to prevent excessive gearbox temperatures?

A) Temperature sensor

Question:
With reference to pneumatically operated friction clutches, what is the effect of angular misalignment?

B) Increased risk of friction pad wear and potential clutch slippage

Question 5:
What is the effect of a loss of air pressure in an air-operated radial tyre type clutch?

C) The clutch will automatically disengage

Question 3:
What component in an air-operated radial tyre type clutch provides the frictional force necessary for torque transmission?

B) Radial tyres

Question:
With reference to pneumatic clutches used for medium-speed main propulsion purposes, how can the clutch be engaged in the event of a failure of the control system?

C) Engage the clutch using a manual override mechanism or emergency procedure

Question 4:
Which of the following is a typical advantage of using an air-operated radial tyre type clutch in a diesel engine propulsion system?

A) High torque capacity and smooth engagement

Question 5:
What is the effect of a loss of air pressure in an air-operated radial tyre type clutch?

C) The clutch will automatically disengage

Question:
With reference to pneumatic clutches used for medium-speed main propulsion purposes, which TWO interlocks are necessary for proper clutch operation?

B) Clutch temperature and air pressure

Question 4:
Which protection device helps to ensure that the pneumatic clutch operates correctly and safely in the event of an air pressure failure?

B) Manual override system

Question:
With reference to pneumatically operated friction clutches, what is the effect of distorted friction pads?

C) Uneven engagement leading to vibration and potential clutch slippage

Question 2:
In a reduction gearing and pneumatic clutch arrangement, which protection device is commonly used to avoid damage from excessive torque?

B) Torque limiter

With reference to pneumatically operated friction clutches, what is the effect of oil contamination on the friction pads?

B) Decreased friction causing slippage and reduced clutch efficiency

Question 4:
What is the purpose of the air pressure control system in a pneumatic clutch used in medium-speed main propulsion?

B) To regulate the engagement and disengagement timing of the clutch

Question 1:
In a diesel engine propulsion system, what is the primary function of an air-operated radial tyre type clutch?

B) To engage or disengage the engine from the propulsion system

Question 3:
How does the release of air pressure affect the operation of a pneumatic clutch?

B) It decreases the engagement force, leading to clutch disengagement

Question 2:
How is the engagement of an air-operated radial tyre type clutch typically controlled?

B) By varying the air pressure supplied to the clutch

1 / 21

MDE Unit 20 reduction gearing

Question 4:
Which technique is used to assess the noise generated by main reduction gearing and diagnose potential faults?

A) Acoustic emission testing

Question 4:
What does the oil pump do in the lubricating oil system for reduction gearing?

C) Circulates the oil through the system

Question 5:
Which of the following is an advantage of helical gears in terms of their load distribution?

B) More uniform load distribution

Question 1:
With reference to reduction gearing, why is the surface finish of gear teeth critical for operational efficiency?

C) It influences the smoothness of the gear operation and reduces friction

Question 5:
In the block diagram of a lubricating oil system, which component is used to monitor and maintain the oil level?

B) Oil Level Gauge

Question 1:
Which of the following is an advantage of helical gear teeth over spur gear teeth?

D) Increased load capacity

Question 1:
Which of the following is a common cause of gear tooth pitting?

A) Excessive load and poor lubrication

Question 1:
In a block diagram of a lubricating oil system for reduction gearing, which component is responsible for filtering contaminants from the oil?

C) Oil Filter

Question 5:
What is the purpose of using ultrasonic testing in the condition monitoring of main reduction gearing?

B) To detect internal defects or cracks

Question 4:
Why might oil sprayers be more effective than a wet sump system for high-speed main reduction gears?

C) They provide targeted and controlled lubrication

Question 4:
What should be done if there is evidence of damage to the gearbox components due to water contamination?

B) Perform an immediate repair or replacement of damaged components

Question 3:
During a gearbox inspection, which component should be checked for excessive wear?

A) Gear teeth

Question 4:
What advantage do helical gears have over spur gears in terms of operational noise?

B) Lower operational noise

Question 1:
What is the first step to take if you discover water contamination in the gearbox oil?

C) Drain the contaminated oil from the gearbox

Question:
How may gearbox oil become contaminated with water?

C) By condensation forming inside the gearbox

Question 3:
With reference to reduction gearing, why is achieving a precise surface finish on gear teeth important for the gear's lifespan?

B) It reduces the chances of tooth breakage and premature wear

Question 2:
One disadvantage of helical gears compared to spur gears is:

B) Higher manufacturing costs

Question 2:
What is a typical sign of gear tooth scuffing?

C) Rough, burnt appearance on the gear teeth

Question 6:
Which of the following is a potential cause of gear tooth flaking?

A) Inadequate gear surface hardening

Question 2:
How does water contamination affect the viscosity of gearbox oil?

B) It decreases viscosity significantly

Question 1:
What is one of the primary effects of water contamination in gearbox oil?

B) Increased friction and wear

Question 2:
After draining the contaminated oil from the gearbox, what should be done next?

A) Replace it with fresh, clean oil

Question 2:
What is a key advantage of using oil sprayers in the lubrication of main reduction gearing?

C) Enhanced oil distribution and reduced wear

Question 4:
With reference to reduction gearing, what role does the surface finish of gear teeth play in the efficiency of power transmission?

C) It helps to minimize energy losses due to friction and improves efficiency

Question 6:
Which component in the lubricating oil system helps to separate air from the oil?

B) Air Separator

Question 3:
What could be a consequence of not supplying lubricating oil before the main reduction gearing starts rotating?

C) Accelerated gear wear and damage

Question 3:
Which protective device in the lubricating oil system helps to prevent damage from excessive oil pressure?

B) Pressure Relief Valve

Question 2:
What is the primary function of the oil cooler in a lubricating oil system for reduction gearing?

B) To cool the lubricating oil

Question 5:
What fault might be observed if gear teeth exhibit a jagged, uneven surface?

C) Gear tooth chipping

Question 3:
One advantage of double helix gears is their effect on axial thrust. What is this effect?

B) Double helix gears produce lower axial thrust.

Question 4:
What is a key disadvantage of double helix gears in terms of noise and vibration compared to single helix gears?

B) Double helix gears generate more noise and vibration.

Question 5:
Which of the following is NOT a benefit of supplying lubricating oil to main reduction gearing before it rotates?

C) Improving gear tooth profile

Question 2:
Which of the following is a common visual inspection technique used for a gearbox?

C) Inspecting for oil leaks and contamination

Question 3:
Which fault is indicated by visible cracks on gear teeth?

D) Gear tooth cracking

Question 5:
What should be checked to assess the condition of the gearbox bearings during an inspection?

A) Bearing temperature and noise levels

Question 5:
To prevent future water contamination of the gearbox, what preventive measure should be implemented?

B) Install proper seals and gaskets to prevent water ingress

Question 2:
What is a primary reason for pre-lubricating the main reduction gearing before it rotates?

B) To ensure smooth gear engagement

Question 2:
Which of the following is a disadvantage of double helix gears compared to single helix gears?

A) Increased manufacturing complexity

Question 5:
Regarding maintenance, which of the following is a disadvantage of double helix gears?

C) More complex alignment and maintenance

Question 4:
What is a common result of gear tooth wear due to improper lubrication?

D) Gear tooth pitting

Question:
With reference to reduction gearing, what is the primary purpose of the magnetic filter in the lubricating oil system?

C) To attract and remove ferrous particles and metal debris from the oil

Question 3:
Which of the following is a disadvantage of helical gears compared to spur gears?

B) Increased axial load

Question 4:
What is one of the potential effects of water contamination on the operational performance of a gearbox?

B) Increased operational temperature

Question 1:
What is a primary advantage of double helix gears over single helix gears?

B) Higher load capacity

Question 3:
How can you confirm that the gearbox has been properly cleaned and the contamination removed?

D) By conducting a thorough inspection and ensuring no water remains

Question 7:
What action should be taken if abnormal noise is detected during a gearbox inspection?

C) Investigate and repair the source of the noise

Question 4:
How does supplying lubricating oil before rotation help with the temperature management of the main reduction gearing?

B) By dissipating heat generated during initial contact

Question 1:
Why is oil spraying preferred over a wet sump for lubricating main reduction gearing?

B) Oil sprayers deliver more uniform lubrication

Question 4:
What tool is often used to measure the backlash in a gearbox?

B) Dial gauge

Question 5:
What should be done if water contamination is detected in the gearbox oil?

B) Drain the contaminated oil and replace it with fresh oil

Question 1:
What is the primary purpose of inspecting a gearbox?

B) To verify the alignment and condition of the gears

Question 1:
Why should lubricating oil be supplied to the main reduction gearing before it starts rotating?

C) To provide initial lubrication and reduce wear

Question 7:
In a lubricating oil system for reduction gearing, what is the purpose of the temperature sensor?

C) To monitor and control oil temperature

Question 6:
What is a primary reason for not relying on a wet sump system for lubrication of main reduction gearing?

B) Insufficient oil coverage due to gear rotation speed

Question 3:
What is a common consequence of water contamination in gearbox oil on the gears?

B) Corrosion and rust formation

Question 3:
Which of the following methods can be used to detect heat build-up in the main reduction gearing?

C) Thermography

Question 6:
Which of the following is a sign of gear tooth damage that should be noted during a gearbox inspection?

B) Cracks or chips on the gear teeth

Question 2:
Which condition monitoring technique involves analyzing the lubricant for signs of wear particles and contamination?

B) Oil analysis

Question 3:
What is a potential drawback of relying on a wet sump system for main reduction gearing lubrication?

B) Inadequate oil delivery to high-speed gears

Question 1:
Which of the following condition monitoring techniques is commonly used to assess the vibration levels of main reduction gearing?

B) Vibration analysis

Question 2:
With reference to reduction gearing, how does a poor surface finish on gear teeth impact the gear's performance?

B) It can cause increased noise and vibration

Question 5:
How does the use of oil sprayers impact the efficiency of main reduction gearing lubrication?

B) It improves the oil film strength on gears

With reference to reduction gearing, why is EP (Extreme Pressure) lubricating oil preferred?

B) It provides excellent protection against wear and extreme pressure conditions

1 / 63