CBTC Train Operation Over Failed Track Circuits

In recent years, many rapid mass transit agencies have chosen Communications-Based Train Control (CBTC) technology to renew their signaling system or to equip a new line. CBTC technology is a type of Automatic Train Control (ATC) that allows transit agencies to increase nominal throughput and to improve safety. CBTC technology can operate without fixed wayside track detectors such as track circuits. However, track circuit equipment continues to be implemented on the tracks and in the equipment rooms. For authorities under the Federal Railroad Administration, current regulations require use of track circuit but the main functional reason is to have a backup system in case of CBTC failure. Most transit agencies decide to include track circuit occupied and vacant status into the CBTC system in order to enhance safety. The additional safety feature brings a new challenge: how to detect and to manage CBTC operation when track circuit failure occurs. This paper discusses the challenges of maintaining safe and efficient train operation over failed track circuits. The consequences of the track circuit failures on the signaling system are not addressed in this paper. First, the different type of track circuit failures and how the CBTC system detects them are introduced. Then the paper discusses possible restrictions on CBTC train operation and the associated enforcement methods. Finally, the different methods to return to normal CBTC operation, after the failure has been fixed, are presented. Transit agencies’ different approaches to maintain safe operation, as well as possible future options to manage track circuits failures with a CBTC system, are explained.

• Record URL:
  • http://www.apta.com/mc/rail/previous/2013/papers/Papers/DiemunschK_CBTC-Train-Operation-Over-Failed-Track-Circuits.pdf
• 
• Supplemental Notes:
  • Abstract used with permission from American Public Transportation Association.
• Corporate Authors:

  American Public Transportation Association

  1666 K Street, NW, Suite 1100
  Washington, DC  United States  20006
• Authors:
  • Diemunsch, Kenneth M
• Conference:
  • 2013 Rail Conference
  • Location: Philadelphia PA, United States
  • Date: 2013-6-2 to 2013-6-5
• Publication Date: 2013

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: 7p
• Monograph Title: 2013 Rail Conference

Subject/Index Terms

• TRT Terms: Automatic train control; Detection and identification; Mechanical failure; Railroad safety; Rapid transit; Track circuits
• Identifier Terms: Communications Based Train Control
• Subject Areas: Operations and Traffic Management; Railroads; I73: Traffic Control;

Filing Info

• Accession Number: 01502490
• Record Type: Publication
• Files: TRIS
• Created Date: Dec 24 2013 1:09PM