CE 515 Railroad Engineering Operations of Railways “Transportation exists to conquer space and time -” Safety • FRA responsible for safety • Safety never deregulated • All accidents reported • Safety and Loss Control Department 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 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) Rail Traffic Control Systems • Track Warrant Control (TWC) • Direct Traffic Control (DTC) • Automatic Block Signal (ABS) • Centralized Traffic Control (CTC) 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 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 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 Automatic Block Signal (ABS) http://www.youtube.com/watch?v=U8yGNKH 2t3g 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 Centralized Traffic Control (CTC) http://mysite.du.edu/~jcalvert/railway/ctc.htm Centralized Traffic Control (CTC) 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 Centralized Traffic Control (CTC) • Single track: 70% of capacity of double track with ABS • Railways: shift to CTC: excess capacity Questions?