1. CE 515 Railroad Engineering
Operations of Railways
“Transportation exists to conquer space and time -”

2. Safety FRA responsible for safety Safety never deregulated
All accidents reported
Safety and Loss Control Department

3. Tracks
Main tracks: governed by one or more methods of control. Should not be occupied without permission or authority
Other than main tracks: occupancy without authority, the locomotive engineer should look for other movements, usually max 20mph

4. Speed
Higher speed: improve capacity and productivity but also risk and maintenance cost
Separate speed according to the type of train
Temporary Speed Restrictions (TSR) and Permanent Speed Restrictions (PSR)

5. Rail Traffic Control Systems
Track Warrant Control (TWC)
Direct Traffic Control (DTC)
Automatic Block Signal (ABS)
Centralized Traffic Control (CTC)

6. Rail Traffic Control Systems
TWC, DTC: Non-signalized systems
Use radio communication and computers
Rail Traffic Controller (RTC): order transferred by radio and written by crew

7. Automatic Block Signal (ABS)
Series of consecutive blocks governed by block signals, cab signals, or both. Signals activated by a train moving through the block, or by certain conditions that affect the block use.
Developed in 1872, Dr. William Robinson
Divide “tracks” into blocks, only one train per block
Directional operations, two or more tracks
Designated current of traffic, low-density single tracks

8. Automatic Block Signal (ABS)
Track circuit
Fail-safe design
Length of block: equal to longest normal stopping distance
“Two-block, three-indication”, “Three-block, four-indication”
Remained ABS systems: operated by TWC rules

9. Automatic Block Signal (ABS)

10. Centralized Traffic Control (CTC)
Track territories, double track sections: crossing over is allowed.
Rail Traffic Control Center: all track circuits connected, controlled together
Panel: showing position of each train

11. Centralized Traffic Control (CTC)

12. Centralized Traffic Control (CTC)

13. Centralized Traffic Control (CTC)
Authority to enter a CTC main track: by signal.
Crew requests for permission by radio
Opposing movements: not allowed, only following train movements
“Intermediate signals”: facilitate fleeting of trains

14. Centralized Traffic Control (CTC)
Single track: 70% of capacity of double track with ABS
Railways: shift to CTC: excess capacity

15. Questions?