What is the minimum temperature required for coal gas to ignite?
- 1,500 degrees Fahrenheit
- 1,800 degrees Fahrenheit
- 2,100 degrees Fahrenheit
- 2,400 degrees Fahrenheit
Correct Answer: 1,800 degrees Fahrenheit
Correct Answer Explanation: Coal gas needs to reach 1,800 degrees Fahrenheit to ignite and sustain combustion. This is a key factor in efficient coal firing, as it ensures the complete burning of gases for maximum steam generation.
What is the approximate pressure per square foot on a locomotive boiler at 200 pounds per square inch?
- 10 tons
- 15 tons
- 20 tons
- 25 tons
Correct Answer: 15 tons
Correct Answer Explanation: A locomotive boiler at 200 pounds per square inch of pressure experiences a massive force of about fifteen tons per square foot. This highlights the incredible strength required for boiler construction and the importance of maintaining safe operating pressures.
What is the main purpose of a steam dome on a locomotive boiler?
- To increase the boiler’s capacity
- To store excess water
- To provide space for dryer steam
- To regulate steam pressure
Correct Answer: To provide space for dryer steam
Correct Answer Explanation: A steam dome on a locomotive boiler serves as a storage space for dryer steam, ensuring a consistent supply of steam to the engine. It also houses vital components like safety valves, steam pipes, and the throttle valve.
What is the typical adjustment for the safety valve in the control valve of an air brake system?
- 20 pounds
- 30 pounds
- 40 pounds
- 50 pounds
Correct Answer: 50 pounds
Correct Answer Explanation: The safety valve in the control valve of an air brake system is typically adjusted to 50 pounds, preventing excessive pressure buildup and potential failures.
What is the main function of the ash pan on a locomotive?
- To collect ashes and prevent them from setting fire to bridges or other property
- To regulate the flow of air into the firebox
- To protect the firebox from damage
- To reduce the amount of smoke produced
Correct Answer: To collect ashes and prevent them from setting fire to bridges or other property
Correct Answer Explanation: The ash pan on a locomotive serves as a container for the ashes produced during combustion. It prevents the ashes from being blown onto surrounding areas and potentially causing fires.
What is a common cause of honeycomb formation on locomotive flues?
- The buildup of soot and grime
- The use of low-quality coal
- The presence of sulfur and molten clay in the fire
- The over-firing of the boiler
Correct Answer: The presence of sulfur and molten clay in the fire
Correct Answer Explanation: The presence of sulfur and molten clay in the fire can stick to the flue sheets and clog up the netting in the front end, leading to the formation of honeycomb. This reduces the heating surface and hinders the engine’s ability to steam efficiently.
What is the approximate volume increase of superheated steam for each 100 degrees of superheat?
- 10-11%
- 16-17%
- 21-22%
- 26-27%
Correct Answer: 16-17%
Correct Answer Explanation: Superheated steam experiences a significant volume increase, with every 100 degrees of superheat resulting in approximately a 16-17% expansion. This increased volume directly contributes to improved locomotive efficiency and reduced fuel consumption.
What is the typical adjustment for the excess pressure head of the compressor governor in an air brake system?
- 10 pounds above brake pipe pressure
- 15 pounds above brake pipe pressure
- 20 pounds above brake pipe pressure
- 25 pounds above brake pipe pressure
Correct Answer: 20 pounds above brake pipe pressure
Correct Answer Explanation: The excess pressure head of the compressor governor is typically adjusted to 20 pounds above brake pipe pressure. This ensures sufficient pressure for brake applications and provides a safety margin to prevent overcharging of the brake system.
What is the main function of the eccentric in a locomotive valve gear?
- To regulate the flow of steam to the cylinders
- To convert rotational motion into reciprocating motion
- To control the speed of the engine
- To lubricate the valve mechanism
Correct Answer: To convert rotational motion into reciprocating motion
Correct Answer Explanation: The eccentric in a locomotive valve gear plays a crucial role in converting the rotational motion of the driving wheels into the reciprocating motion required for operating the valves. This ensures proper timing of steam admission and exhaust, which is essential for the engine’s operation.
What is the typical pressure developed by the independent brake valve in an air brake system?
- 35 pounds
- 40 pounds
- 45 pounds
- 50 pounds
Correct Answer: 45 pounds
Correct Answer Explanation: The independent brake valve typically develops about 45 pounds of pressure, enabling the engineer to independently control the locomotive brakes without affecting the brakes on the train.
What is the main purpose of the distributing valve on a locomotive?
- To regulate the flow of steam to the cylinders
- To control the application and release of the locomotive brake
- To monitor the air pressure in the brake system
- To operate the injector
Correct Answer: To control the application and release of the locomotive brake
Correct Answer Explanation: The distributing valve on a locomotive plays a crucial role in controlling the application and release of the locomotive brakes. It receives signals from the engineer’s brake valve and directs the flow of air to the brake cylinders, ensuring smooth and efficient braking.
What is the main function of the feed valve in an air brake system?
- To regulate the flow of air to the brake cylinders
- To maintain the desired pressure in the brake pipe
- To control the speed of the compressor
- To provide a safety valve for the brake system
Correct Answer: To maintain the desired pressure in the brake pipe
Correct Answer Explanation: The feed valve plays a crucial role in maintaining the desired pressure in the brake pipe, ensuring consistent brake performance and safety. It automatically regulates the flow of air from the main reservoir into the brake pipe, replenishing air that is used during brake applications.
What is the purpose of the angle cock in an air brake system?
- To allow the engineer to isolate sections of the train
- To control the flow of air to the brake cylinders
- To provide a safety valve for the brake system
- To monitor the air pressure in the brake system
Correct Answer: To allow the engineer to isolate sections of the train
Correct Answer Explanation: The angle cock, located at the end of each brake pipe section, allows the engineer to isolate sections of the train. This is essential for emergency situations, such as a broken train line, enabling the engineer to apply brakes on the isolated sections while protecting the remaining train.
How does the injector on a locomotive work?
- It uses steam to draw water into the boiler
- It uses air pressure to draw water into the boiler
- It uses centrifugal force to draw water into the boiler
- It uses gravity to draw water into the boiler
Correct Answer: It uses steam to draw water into the boiler
Correct Answer Explanation: The injector is a crucial component of a locomotive’s water supply system. It works by using the energy of steam to draw water from the tender and force it into the boiler, overcoming the pressure inside the boiler. The steam condenses, creating a vacuum that pulls water through the injector.
What is the typical number of strokes per minute for a locomotive compressor?
- 50-60 strokes per minute
- 70-80 strokes per minute
- 90-100 strokes per minute
- 100-120 strokes per minute
Correct Answer: 100-120 strokes per minute
Correct Answer Explanation: A locomotive compressor typically operates at a speed of 100-120 strokes per minute, ensuring efficient air compression to maintain sufficient pressure for brake applications.
What is the purpose of the cut-out cock in an air brake system?
- To disable a brake on a car
- To control the flow of air to the brake cylinders
- To provide a safety valve for the brake system
- To monitor the air pressure in the brake system
Correct Answer: To disable a brake on a car
Correct Answer Explanation: The cut-out cock is a valve used to disable a brake on a car if it is malfunctioning or needs to be repaired. This allows the remaining brakes in the train to operate normally.
What is the main advantage of a compound locomotive over a simple engine?
- Greater speed
- Higher power output
- Increased fuel efficiency
- Improved hauling capacity
Correct Answer: Increased fuel efficiency
Correct Answer Explanation: Compound locomotives offer significant advantages over simple engines, particularly in terms of fuel efficiency. By using steam expansively through multiple cylinders, they extract more energy from the steam, reducing fuel consumption and improving overall performance.
What is the main function of the triple valve in an air brake system?
- To control the flow of air to the brake cylinder
- To regulate the air pressure in the brake pipe
- To monitor the air pressure in the brake system
- To provide a safety valve for the brake system
Correct Answer: To control the flow of air to the brake cylinder
Correct Answer Explanation: The triple valve, a crucial component of the air brake system, is responsible for controlling the flow of air to the brake cylinder on each car. It receives signals from the brake pipe and the auxiliary reservoir and directs the flow of air to apply or release the brakes, ensuring proper and safe braking.
What is the main purpose of the retaining valve on a freight car?
- To prevent the brakes from releasing too quickly
- To increase the braking force
- To regulate the air pressure in the brake cylinder
- To provide a safety valve for the brake system
Correct Answer: To prevent the brakes from releasing too quickly
Correct Answer Explanation: The retaining valve is designed to help hold the brakes applied on a car while the auxiliary reservoir recharges, preventing the brakes from releasing too quickly on steep grades or when stopping on a downgrade. It ensures smoother and more controlled braking on challenging terrain.
What is the main function of the safety valve on a locomotive boiler?
- To regulate the flow of steam to the cylinders
- To prevent the boiler from exploding due to excessive pressure
- To control the air pressure in the brake system
- To monitor the water level in the boiler
Correct Answer: To prevent the boiler from exploding due to excessive pressure
Correct Answer Explanation: The safety valve is a critical safety device on a locomotive boiler. It is designed to automatically release steam when the boiler pressure reaches a predetermined maximum limit, preventing catastrophic failure due to excessive pressure buildup.
What is the main function of the draft pipes in a locomotive’s front end?
- To regulate the flow of air to the firebox
- To control the speed of the engine
- To prevent the boiler from exploding due to excessive pressure
- To monitor the water level in the boiler
Correct Answer: To regulate the flow of air to the firebox
Correct Answer Explanation: The draft pipes in the front end of a locomotive play a critical role in regulating the flow of air to the firebox, ensuring efficient combustion and steam generation. They create a draft that pulls air through the firebox, promoting the burning of coal and generating heat for the boiler.
What is the main purpose of the diaphragm in a locomotive’s front end?
- To regulate the flow of air to the firebox
- To control the speed of the engine
- To prevent the boiler from exploding due to excessive pressure
- To monitor the water level in the boiler
Correct Answer: To regulate the flow of air to the firebox
Correct Answer Explanation: The diaphragm in the front end of a locomotive works in conjunction with the draft pipes to regulate the flow of air to the firebox. It helps control the direction and intensity of the draft, ensuring proper combustion and efficient steam generation.
What is the main purpose of the exhaust nozzle in a locomotive’s front end?
- To regulate the flow of air to the firebox
- To control the speed of the engine
- To create a vacuum in the smokebox to draw air through the firebox
- To prevent the boiler from exploding due to excessive pressure
Correct Answer: To create a vacuum in the smokebox to draw air through the firebox
Correct Answer Explanation: The exhaust nozzle plays a critical role in creating a vacuum in the smokebox, which in turn draws air through the firebox, promoting combustion and steam generation. It helps to regulate the amount of steam released from the cylinders, influencing the draft and efficiency of the engine.
How does a wide firebox boiler differ from a narrow firebox boiler?
- It has a larger grate area and a slower rate of combustion
- It has a smaller grate area and a faster rate of combustion
- It has a higher capacity but a lower efficiency
- It is more complex to operate and maintain
Correct Answer: It has a larger grate area and a slower rate of combustion
Correct Answer Explanation: Wide firebox boilers offer a distinct advantage over narrow firebox boilers by providing a larger grate area, which allows for a slower rate of combustion. This slower burning process leads to more efficient utilization of coal and reduces the formation of clinkers and black smoke.
How can you identify a broken hollow staybolt on a locomotive?
- Steam will escape through a small hole in the bolt
- The boiler pressure will drop
- The engine will lose power
- The water level will rise
Correct Answer: Steam will escape through a small hole in the bolt
Correct Answer Explanation: Hollow staybolts are designed to indicate a failure. If the bolt breaks, steam will escape through a small hole in the bolt, alerting the engineer to a potential problem.
What is a common indication of a clinkered fire in a locomotive firebox?
- A drop in boiler pressure
- An increase in smoke volume
- A partial vacuum in the smokebox
- A loss of engine power
Correct Answer: A partial vacuum in the smokebox
Correct Answer Explanation: A clinkered fire, characterized by the buildup of clinkers on the grate, can restrict airflow and create a partial vacuum in the smokebox. This indicates a reduction in the draft and potentially inefficient combustion, requiring immediate attention.
What is the main function of the staybolts in a locomotive firebox?
- To regulate the flow of steam to the cylinders
- To prevent the boiler from exploding due to excessive pressure
- To support the firebox sheets and prevent them from collapsing
- To monitor the water level in the boiler
Correct Answer: To support the firebox sheets and prevent them from collapsing
Correct Answer Explanation: Staybolts are essential for maintaining the structural integrity of the firebox, preventing it from collapsing under the immense pressure. They act as supports, connecting the firebox sheets and the outer shell of the boiler, ensuring a secure and robust structure.
What is a common sign of incomplete combustion in a locomotive firebox?
- A drop in boiler pressure
- An increase in smoke volume
- A high-pitched whistle
- A loss of engine power
Correct Answer: An increase in smoke volume
Correct Answer Explanation: Incomplete combustion occurs when the coal does not burn fully, resulting in the production of black smoke. This is a clear indication of inefficient burning and suggests a need to adjust firing techniques or address potential issues in the draft system.
What is the typical reduction in brake pipe pressure needed for a full brake application?
- 10 pounds
- 15 pounds
- 20 pounds
- 25 pounds
Correct Answer: 20 pounds
Correct Answer Explanation: A reduction of about 20 pounds from a typical 70-pound brake pipe pressure is required for a full brake application. This reduction in pressure triggers the triple valves to apply the brakes on each car in the train, ensuring a smooth and efficient braking action.
What is the typical setting for the maximum pressure head in an air brake system?
- 100 pounds
- 110 pounds
- 120 pounds
- 130 pounds
Correct Answer: 130 pounds
Correct Answer Explanation: The maximum pressure head in an air brake system is typically set at 130 pounds. This setting ensures that the compressor does not overcharge the main reservoir and potentially cause damage to the system.
What is the typical lift for air valves in a locomotive compressor?
- 1/32-inch
- 1/16-inch
- 3/32-inch
- 1/8-inch
Correct Answer: 3/32-inch
Correct Answer Explanation: Air valves in locomotive compressors are typically designed with a lift of 3/32-inch. This precise lift allows for efficient and consistent air intake during the compression process, ensuring optimal performance of the compressor.
What is the typical steam cylinder diameter for the high-pressure cylinder in a cross-compound compressor?
- 6 inches
- 7 inches
- 8 ½ inches
- 10 inches
Correct Answer: 8 ½ inches
Correct Answer Explanation: The high-pressure steam cylinder in a cross-compound compressor typically has a diameter of 8 ½ inches. This diameter, combined with the low-pressure cylinder diameter, allows for efficient steam utilization and effective air compression.
What is the typical steam cylinder diameter for the low-pressure cylinder in a cross-compound compressor?
- 12 inches
- 13 inches
- 14 ½ inches
- 16 inches
Correct Answer: 14 ½ inches
Correct Answer Explanation: The low-pressure steam cylinder in a cross-compound compressor typically has a diameter of 14 ½ inches. This larger diameter allows for efficient expansion of the steam, maximizing its energy transfer to the air cylinders.
What is the typical air cylinder diameter for the low-pressure cylinder in a cross-compound compressor?
- 12 inches
- 13 inches
- 14 ½ inches
- 16 inches
Correct Answer: 14 ½ inches
Correct Answer Explanation: The low-pressure air cylinder in a cross-compound compressor typically has a diameter of 14 ½ inches. This larger diameter allows for efficient intake and compression of the air, leading to the desired pressure levels for brake applications.
What is the typical air cylinder diameter for the high-pressure cylinder in a cross-compound compressor?
- 7 inches
- 8 inches
- 9 inches
- 10 inches
Correct Answer: 9 inches
Correct Answer Explanation: The high-pressure air cylinder in a cross-compound compressor typically has a diameter of 9 inches. This diameter, combined with the low-pressure cylinder diameter, ensures efficient compression and delivery of the air to the main reservoir.
What is the main purpose of the dead engine feature in an air brake system?
- To allow the engineer to control the train brakes from a disabled locomotive
- To recharge the main reservoir of a disabled locomotive
- To prevent the brakes from releasing too quickly
- To provide a safety valve for the brake system
Correct Answer: To recharge the main reservoir of a disabled locomotive
Correct Answer Explanation: The dead engine feature is a valuable tool that enables the main reservoir of a disabled locomotive to be charged to about 50 pounds using a functioning locomotive. This feature allows for the release of the brakes on the disabled locomotive, facilitating its movement or repairs.
What is the main function of the lap on a locomotive valve?
- To regulate the flow of steam to the cylinders
- To control the speed of the engine
- To prevent the boiler from exploding due to excessive pressure
- To determine the point at which steam admission is cut off
Correct Answer: To determine the point at which steam admission is cut off
Correct Answer Explanation: The lap on a locomotive valve determines the point at which steam admission is cut off during the piston stroke. It refers to the amount by which the valve overlaps the port opening when it is in its central position, influencing the timing of steam flow and affecting the engine’s performance.
What is the main function of the lead on a locomotive valve?
- To regulate the flow of steam to the cylinders
- To control the speed of the engine
- To prevent the boiler from exploding due to excessive pressure
- To allow for early steam admission and efficient power transfer
Correct Answer: To allow for early steam admission and efficient power transfer
Correct Answer Explanation: The lead on a locomotive valve refers to the amount the steam port is open when the piston is on dead center. This early steam admission ensures smooth and efficient power transfer during the initial stages of the piston stroke, contributing to the overall performance of the engine.
What is the main function of the release on a locomotive valve?
- To regulate the flow of steam to the cylinders
- To control the speed of the engine
- To prevent the boiler from exploding due to excessive pressure
- To open the exhaust port and release steam from the cylinder
Correct Answer: To open the exhaust port and release steam from the cylinder
Correct Answer Explanation: The release on a locomotive valve refers to the point in the piston stroke when the valve opens the exhaust port, allowing steam to escape from the cylinder. This exhaust process is essential for proper engine operation, allowing for the next intake of steam and continuing the power cycle.
What is the main function of the compression on a locomotive valve?
- To regulate the flow of steam to the cylinders
- To control the speed of the engine
- To prevent the boiler from exploding due to excessive pressure
- To compress the remaining steam in the cylinder and prepare for the next intake of steam
Correct Answer: To compress the remaining steam in the cylinder and prepare for the next intake of steam
Correct Answer Explanation: Compression occurs when the exhaust port closes and the remaining steam in the cylinder is compressed. This process helps to cushion the piston as it changes direction and prepares the cylinder for the next intake of steam, contributing to smoother and more efficient engine operation.
What is the approximate amount of water that one pound of coal should evaporate?
- Six to eighty-four gallons
- Twelve to ninety-six gallons
- Eighteen to one hundred and eight gallons
- Twenty-four to one hundred and twenty gallons
Correct Answer: Six to eighty-four gallons
Correct Answer Explanation: The amount of water that one pound of coal can evaporate varies significantly depending on the quality of the coal and the efficiency of the boiler. However, a general range is between six and eighty-four gallons of water per pound of coal.
What is the approximate steam waste per minute when an engine pops off?
- Five pounds
- Ten pounds
- Fifteen pounds
- Twenty pounds
Correct Answer: Fifteen pounds
Correct Answer Explanation: When an engine pops off, meaning the safety valve releases excess pressure, approximately fifteen pounds of coal are wasted per minute. This highlights the importance of maintaining safe operating pressures and preventing unnecessary steam loss, which directly impacts fuel efficiency.
What is the typical temperature at which fuel oil should be kept to flow freely?
- 100 degrees Fahrenheit
- 105 degrees Fahrenheit
- 112 degrees Fahrenheit
- 120 degrees Fahrenheit
Correct Answer: 112 degrees Fahrenheit
Correct Answer Explanation: Fuel oil for locomotive engines should typically be kept at a temperature of 112 degrees Fahrenheit to ensure smooth and efficient flow. This temperature range allows for optimal viscosity, ensuring proper atomization and combustion of the fuel.
What is the recommended steaming time for an oil tank before entering for cleaning or repairs?
- 2-4 hours
- 4-6 hours
- 6-8 hours
- 8-10 hours
Correct Answer: 6-8 hours
Correct Answer Explanation: For safety reasons, oil tanks should be steamed for 6-8 hours before entering for cleaning or repairs. This steaming process allows for the evaporation of any volatile gases or flammable residues within the tank, ensuring a safe working environment.
What is the approximate distance one should maintain between an oil lamp or torch and the opening of a fuel oil tank?
- Five feet
- Seven feet
- Ten feet
- Fifteen feet
Correct Answer: Ten feet
Correct Answer Explanation: For safety reasons, it is crucial to maintain a distance of at least ten feet between any oil lamps or torches and the opening of a fuel oil tank. This distance minimizes the risk of ignition from potential sparks or heat from the open flame, protecting against fire hazards.