LEC Track & Signal Systems 1 — Questions and Answers
Question 1: What does a red signal aspect (Stop) require a locomotive engineer to do?
- Reduce speed to 15 mph and proceed with caution
- Stop and not proceed without proper authority (Correct answer)
- Stop momentarily, then proceed at restricted speed
- Reduce speed to restricted speed and continue
Correct answer: Stop and not proceed without proper authority
A red (Stop) signal is an absolute signal requiring the engineer to stop and not proceed without receiving proper authority from the dispatcher or train control.
Question 2: What is the primary function of a Cab Signal System on a locomotive?
- It controls the locomotive throttle automatically based on grade
- It displays wayside signal aspects inside the cab for the engineer (Correct answer)
- It transmits train speed data to the dispatch center
- It activates the emergency brake when approaching a station
Correct answer: It displays wayside signal aspects inside the cab for the engineer
A cab signal system displays current signal aspects inside the locomotive cab, allowing engineers to receive signal information without needing to see wayside signals.
Question 3: Under FRA track standards, what is the maximum authorized speed for freight trains on Class 4 track?
- 50 mph
- 60 mph (Correct answer)
- 70 mph
- 80 mph
Correct answer: 60 mph
FRA Class 4 track permits a maximum freight train speed of 60 mph and passenger train speed of 80 mph.
Question 4: Which hazard is Positive Train Control (PTC) primarily designed to prevent?
- Derailments caused by broken rails
- Train-to-train collisions and overspeed violations (Correct answer)
- Equipment failures due to hot journal bearings
- Signal malfunctions in dark territory
Correct answer: Train-to-train collisions and overspeed violations
PTC is mandated by the Rail Safety Improvement Act of 2008 to prevent train-to-train collisions, derailments caused by overspeed, and unauthorized train movements through work zones.
Question 5: What does an 'Approach' signal aspect (yellow over red) communicate to the engineer?
- Proceed at maximum authorized speed
- Proceed prepared to stop at the next signal (Correct answer)
- Reduce speed to 30 mph through the next block
- Stop and wait for a track warrant
Correct answer: Proceed prepared to stop at the next signal
An Approach signal means the engineer should proceed prepared to stop before any part of the train passes the next signal.
Question 6: What is the primary purpose of a Track Warrant (Form B) in railroad operations?
- To authorize maintenance crews to perform track inspections
- To grant a train authority to occupy a defined section of track in non-signaled territory (Correct answer)
- To record the engineer's hours of service for FRA compliance
- To authorize a locomotive to exceed the posted track speed limit
Correct answer: To grant a train authority to occupy a defined section of track in non-signaled territory
A Track Warrant (Form B) grants written authority for a train to operate over a specific segment of track, particularly in dark or non-signaled territory where no automatic block signals exist.
Question 7: In an Automatic Block Signal (ABS) system, what does a block signal primarily protect against?
- Speed violations at grade crossings
- Two trains occupying the same block simultaneously (Correct answer)
- Unauthorized personnel entering the right-of-way
- Equipment failures at interlocking switches
Correct answer: Two trains occupying the same block simultaneously
The ABS system uses track circuits to detect train occupancy and displays signals to prevent two trains from entering the same block at the same time.
LEC Track & Signal Systems 1
What does a red signal aspect (Stop) require a locomotive engineer to do?