Improving the Safety and Sustainability of Stray Current Control of DC-Powered Rail Transit Systems

Direct current (DC)-powered transit systems have been faced with major repairs and modifications to signal and traction power systems because of ineffective negative return rail isolation. An indication of the magnitude of the financial costs is cited in a comprehensive research report published by the IEEE in the 1990s, where it was estimated that a major portion of the estimated $500 million per year from stray current corrosion losses was borne by DC-powered transit properties and the surrounding infrastructure assets. This figure does not take into account the costs associated with signal problems and repairs. The cost to DC-powered transit systems has been increasing steadily due to stray current issues. What is stray current? How do I know I have it? What do I do to mitigate it? What levels of stray current are acceptable? What levels of rail-to-earth potential are acceptable? How large is the transit corridor for protection? What levels of track-to-earth and rail-to-rail resistance are required? What maintenance testing is required? What costs and safety issues are related to signal system failure? How is maintenance testing conducted? The need for specific criteria for these areas is required for the transit community to make appropriate decisions concerning the costs and implementation of control measures. Research is needed to develop a Guidebook on design and sustainability of stray current control and control of railcar-to-earth and rail-to-earth voltages for DC-powered rail transit systems, including (a) a primer that explains all significant issues in readily understandable terms for non-technical people, (b) guidelines addressed to design and maintenance practitioners (e.g., recommended hazard analysis and safety certification checklist items), (c) case studies (third rail and overhead contact), and (d) recommendations for further research. Implementation of results from this research may significantly reduce start-up and ongoing problems in new and existing DC-powered rail transit systems, including signal failures; controlling railcar-to-earth and rail-to-earth voltages; and the loss of public metallic assets over time, owned by transit agencies, municipalities, public utilities, and others. System safety and stability may be significantly improved, while maintenance costs and train delays may be substantially reduced. This research could potentially influence new system construction, extensions, and maintenance and operation of existing systems. The objective of this research is to develop a Guidebook on design and sustainability of stray current control and control of railcar-to-earth and rail-to-earth voltages for DC-powered rail transit systems. The Guidebook shall include (a) a primer that explains all significant issues in readily understandable terms by non-technical people, (b) guidelines addressed to design and maintenance practitioners (e.g., recommended hazard analysis and safety certification checklist items), (c) case studies (third rail and overhead contact), and (d) recommendations for further research.

Language

  • English

Project

  • Status: Active
  • Funding: $349921
  • Contract Numbers:

    Project D-16

  • Sponsor Organizations:

    Federal Transit Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    Transit Cooperative Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC    20001
  • Project Managers:

    Parker, Stephan

  • Performing Organizations:

    Corrpro Companies, Incorporated

    14701 Flint Lee Road, Suite "G"
    Chantilly, VA  United States  20151-1505
  • Principal Investigators:

    Memon, Saud

    Flounders, Emer

  • Start Date: 20120216
  • Expected Completion Date: 20180630
  • Actual Completion Date: 0
  • Source Data: RiP Project 37926

Subject/Index Terms

Filing Info

  • Accession Number: 01547222
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project D-16
  • Files: TRB, RiP
  • Created Date: Dec 4 2014 1:00AM