FRA Locomotive Engine Systems 3 — Questions and Answers
Question 1: Which FRA regulation governs locomotive inspection and maintenance requirements?
- 49 CFR Part 229 (Correct answer)
- 49 CFR Part 218
- 49 CFR Part 232
- 49 CFR Part 215
Correct answer: 49 CFR Part 229
49 CFR Part 229 (Railroad Locomotive Safety Standards) establishes the federal requirements for locomotive inspection, testing, and maintenance.
Question 2: What is the maximum allowable time a locomotive may operate with a defective automatic train stop system under FRA rules before being removed from service?
- 4 hours
- 8 hours
- Until the next calendar-day inspection
- It must be removed immediately (Correct answer)
Correct answer: It must be removed immediately
Under 49 CFR Part 236, a locomotive with an inoperative automatic train stop or train control system must be removed from service immediately or operated under special restrictions.
Question 3: What type of engine is used in most modern North American freight locomotives?
- Four-stroke gasoline engine
- Two-stroke diesel engine driving AC traction motors (Correct answer)
- Gas turbine connected to a hydraulic transmission
- Two-stroke diesel engine driving DC traction motors only
Correct answer: Two-stroke diesel engine driving AC traction motors
Modern North American freight locomotives (e.g., GE ES44 and EMD SD70) use two-stroke or four-stroke diesel engines paired with AC traction motors for improved adhesion and control.
Question 4: What does the term 'notch 8' refer to on a locomotive throttle?
- The eighth position on the brake valve
- The maximum power position of the throttle controller (Correct answer)
- The eighth dynamic brake position
- The eighth fuel injection advance setting
Correct answer: The maximum power position of the throttle controller
North American locomotives use an 8-notch throttle system where notch 8 commands maximum engine horsepower output.
Question 5: A locomotive engine coolant temperature rises above the high-temperature limit. Which automatic protective action typically occurs?
- Fuel injection is enriched to cool combustion
- Engine power is reduced or the engine shuts down automatically (Correct answer)
- The turbocharger bypass valve opens to reduce load
- The air compressor cuts out to reduce heat load
Correct answer: Engine power is reduced or the engine shuts down automatically
Most modern locomotives have engine protection circuits that automatically reduce power or shut down the engine when coolant temperature exceeds safe limits to prevent catastrophic damage.
Question 6: Which component in the locomotive air brake system provides the main reservoir with compressed air?
- Brake valve
- Air compressor (Correct answer)
- Equalizing reservoir
- Brake pipe
Correct answer: Air compressor
The engine-driven air compressor charges the main reservoir, which then supplies compressed air to all pneumatic systems on the locomotive.
Question 7: What is the purpose of the wheel slip detection and correction system on a modern AC locomotive?
- Monitor tire wear on drive wheels
- Detect and correct loss of adhesion to maximize tractive effort (Correct answer)
- Prevent dynamic brake from locking wheels
- Alert the crew when the speedometer is inaccurate
Correct answer: Detect and correct loss of adhesion to maximize tractive effort
Wheel slip detection systems sense differences in axle rotation speeds and automatically reduce power to slipping axles, then restore it, maximizing adhesion without crew intervention.
FRA Locomotive Engine Systems 3
Which FRA regulation governs locomotive inspection and maintenance requirements?