FRA Signal Employee case studies
FRA Signal Employee · Put your knowledge to work in context.
The FRA Signal Employee credential applies to railroad signal workers whose duties fall under the Federal Railroad Administration's signal inspection, testing, and maintenance rules, chiefly 49 CFR Parts 234, 235, and 236. It is aimed at signal maintainers, signal inspectors, signalmen, and the supervisors who direct them, and it tests whether a worker can install, test, inspect, and repair signal and warning systems while protecting trains and roadway workers. The FRA Signal Employee case studies are 5 cases and about 3,903 words.
1Far-End Shunt Failure on a Coded Track Circuit
At 14:05 on a dry July afternoon you are testing the 4,800-ft coded track circuit in Block 118-2, MP 118.4 to 119.6, on a single-track ABS subdivision where freight is limited to 49 mph. With the block unoccupied the track relay is picked at 4.2 mA and the feed resistor is tapped at 0.9 ohm at the west end; the last test sheet, 11 months ago, recorded a 2.0-ohm tap.
849 words, about 4 min2Late Gate Activation After a Train Stops in the Approach
MP 42.6 is a two-main crossing with flashing lights, gates, constant-warning-time predictors, island circuits and standby batteries. Passenger speed is 55 mph, freight 40 mph, and the design provides a 20-second minimum warning time.
753 words, about 4 min3Switch Indication With a 1/2-Inch Obstruction
At 23:10 on a Sunday you finish replacing a failed switch circuit controller on power switch 3 at CP Marion, a 45-mph universal crossover on a double-track main. The points and stock rails are clean and the point gap measures 1/4 inch.
784 words, about 4 min4Loose Neutral in a Live Signal Service Panel
At 09:20 you answer an "AC FAIL" alarm at the MP 210 bungalow. The service is 120/240 V single-phase from a 7.2-kV pole transformer; the panel's calculated available fault current is 6,200 A at 240 V; the main is a 100-A pull-out fusible disconnect with no integral hasp; the 2016 label reads "Arc Flash Hazard: 3.1 cal/cm² at 18 in." You find a discolored, loose neutral lug.
749 words, about 4 min5PTC Stop Target Where the Wayside Signal Is Clear
CP 88 was cut over six days ago with a new intermediate signal. Since then, eastbound trains receive an onboard PTC stop target about 1,600 ft west of the signal even though the signal displays Clear and the dispatcher's display shows three clear blocks ahead.
768 words, about 4 min