FRA Signal Systems & Train Control 2 — Questions and Answers
Question 1: Under FRA regulations, what is the maximum authorized speed for a passenger train operating on track equipped with only cab signals and no wayside signals?
- 79 mph
- 90 mph
- 110 mph (Correct answer)
- 125 mph
Correct answer: 110 mph
FRA regulations permit passenger trains to operate up to 110 mph on track with cab signal systems that meet the requirements of 49 CFR Part 236.
Question 2: What does a flashing lunar (white) indication on an absolute signal typically communicate to a train crew?
- Proceed at maximum speed
- Proceed prepared to pass next signal at restricted speed (Correct answer)
- Stop — signal malfunction detected
- Tumble-down — signal not in use
Correct answer: Proceed prepared to pass next signal at restricted speed
A flashing lunar indication is commonly used as a permissive aspect directing crews to proceed prepared to pass the next signal at restricted speed.
Question 3: According to 49 CFR Part 236, what minimum test frequency is required for the full signal system functional test on automatic block signal systems?
- Daily
- Weekly
- Annually (Correct answer)
- Every six months
Correct answer: Annually
49 CFR Part 236 requires that full functional tests of automatic block signal systems be performed at least annually.
Question 4: Which component of a coded track circuit modulates the rail current to convey speed or signal information to the locomotive?
- Relay coil
- Code transmitter (Correct answer)
- Impedance bond
- Decoupling capacitor
Correct answer: Code transmitter
The code transmitter interrupts or modulates track circuit current at specific rates to communicate different cab signal aspects to onboard receivers.
Question 5: A train enters a dark signal territory where wayside signals are not illuminated. What action is required?
- Proceed at normal authorized speed
- Proceed at restricted speed, prepared to stop short of any obstruction (Correct answer)
- Stop and contact the dispatcher immediately
- Reverse the train and exit the block
Correct answer: Proceed at restricted speed, prepared to stop short of any obstruction
FRA rules and operating rules require that dark signals be treated as the most restrictive indication, typically requiring restricted speed.
Question 6: What is the primary purpose of an impedance bond in a track circuit at a rail joint?
- To increase traction current flow through the rails
- To provide a low-impedance path for traction return current while blocking signal current (Correct answer)
- To detect broken rails electronically
- To amplify signal relay voltage
Correct answer: To provide a low-impedance path for traction return current while blocking signal current
Impedance bonds allow high-frequency traction return current to pass while blocking audio-frequency signal current so track circuits remain functional.
Question 7: Under Positive Train Control (PTC) regulations, what must happen when a PTC system becomes non-functional on a train required to have it?
- The train may continue at reduced speed indefinitely
- The train must stop at the next station for repairs
- The railroad must notify FRA and comply with 49 CFR 236.1029 provisions (Correct answer)
- Operations continue normally until end of trip
Correct answer: The railroad must notify FRA and comply with 49 CFR 236.1029 provisions
When PTC becomes non-functional, railroads must notify FRA and follow 49 CFR 236.1029, which governs operations during system failures.
FRA Signal Systems & Train Control 2
Under FRA regulations, what is the maximum authorized speed for a passenger train operating on track equipped with only cab signals and no wayside signals?