IEEE Electrification Magazine - September 2014 - 31

with other tests to pinpoint the exact location in complicated scenarios.

resistivity, stray-current corrosion is a concern for all kinds of
track and needs to be addressed during the design, construction, and maintenance of dc-powered rail transit systems.

summary
As a result of the dynamic nature of the stray-current problem,
it is challenging to control the stray current within allowable
limits. However, with appropriate design decisions, meticulousness during construction, and a proper maintenance and
testing regime, the stray-current leakage can be controlled
within limits. The recent advances in the stray-current collection have also validated the use of a combination of mitigation
methods and collection techniques for the control of stray current. The common application of this approach includes the
use of rail boot and other design and construction mitigation
techniques such as insulated fasteners, substation spacing in
combination with steel reinforcement mesh, and a currentcollection technique. It can be concluded that although the
technical advancements have been made in the mitigation
and collection techniques for stray currents and new methods
have been implemented by transit agencies, most of the mitigation methods used today are the same as suggested by the
corrosion committees in the early 1920s.
In transit agencies that have a regular maintenance and
testing plan along with correctly designed mitigation measures, it was observed that they have a better handle on the
stray-current leakage. This makes the regular testing of the
tracks an important aspect, and this cost should be accounted
in the transit agencies maintenance budget. In fact, assessment of the potential corrosion resulting from stray current
should be a part of the planning and design process at the very
inception of all projects and the testing of the stray-current corrosion must continue through the revenue service.
Another aspect that was realized during the research is
the need and importance of having trained corrosioncontrol staff on the transit agency payroll. Transit agencies
are aware that stray current is a serious issue, and it would
benefit them greatly if their staff is trained on the fundamentals of the stray current. This would not only help
address any potential stray-current issues early on but
would also aid the transit agency in conducting early
testing of the rail track. Additionally, it was observed that
the transit agencies are not keeping a log of the corrosion
issues caused by the stray current and the money spent to
mitigate those corrosion problems. This kind of tracking
would be extremely beneficial to the rail industry in assessing the economic and logistic burden borne by rail transit
agencies as a direct impact of stray-current corrosion.
Stray-current issues have been around since the first electric railways were placed into operation and can create safety
hazards and have serious effects on utility structures and the
transit infrastructure itself. Since most of the heavily affected
systems are street railways or trolleys, the areas in which the
railways were built were also most likely to have underground metallic structures like utility piping, thus making it
necessary to have stray-current leakage control. Although
more of an issue in embedded tracks and tracks with low soil

references
[1] J. J. Meany, Jr., "A history of stray traction current corrosion in
the United States," Paper Number 152, Corrosion/74, Chicago, IL,
NACE, 1974.
[2] P. R. Roberge, Handbook of Corrosion Engineering. New York:
McGraw-Hill, 2000.
[3] C. Charalambous and I. Cotton, "Influence of soil structures on corrosion performance of floating DC transit systems," IET Electr. Power Appl., vol. 1, no. 1, pp. 9-16, Jan. 2007.
[4] B. J. Arnold. (1921). Report of the American Committee on
Electrolysis [Online]. Available: https://archive.org/details/
reportofamerican00amerrich
[5] Transit Cooperation Research Program (TCRP), "Track
design handbook for light rail transit," Transportation
Research Board, Report 57, National Academy Press, 2000.
[6] F. C. Robles Hernandez, K. Koch, and G. P. Barrera, "Rail base
corrosion detection and prevention," TCRP-37 (Appendix D-
Estimation of the magnitude of the stresses formed due to corrosion cracks in railway rails, G. P. Barrera and D. Jaramillo), 2007.
[7] K. D. Pham, R. S. Thomas, and W. E. Stinger, "Analysis of stray
current, track-to-earth potentials & substation negative grounding in dc traction electrification system," in Proc. IEEE/ASME Joint
Rail Conf., Toronto, Ontario, Canada, pp. 141-160, 2001.
[8] B. M. Collum and K. H. Logan, "Leakage of currents from
electric railways," Department of Commerce, Technology
Papers of the Bureau of Standards No. 63, 1916.
[9] M. J. Szeliga, Stray Current Corrosion: The Past, Present,
and Future of Rail Transit Systems. NACE International, 1994.
[10] S. Memon, "Understanding stray current mitigation, testing, and maintenance on dc powered rail transit systems," in
ASME Proc., 2013, JRC 2013-2470.
[11] S. Memon and P. Fromme, "Use of rail boot and collection
mat to control the electrolysis of rail and utilities in DC powered transit agencies," in ASME Proc., 2014, JRC 2014-3803.
[12] I. Cotton, C. Charalambous, P. Aylott, and P. Ernst, "Stray
current control in dc mass transit system," IEEE Trans. Veh.
Technol., vol. 54, no. 2, pp. 722-730, 2005.
[13] E. A. Wetzel and H. Fuller, "Stray current control using the
rail boot," in Proc. Track and Structure Technology Innovation,
Commuter Rail/Rapid Transit Conf., 1999.
[14] K. D. Pham, R. S. Thomas, and W. E. Stinger, Jr., "Operational and safety considerations for light rail dc traction electrification system design," Transportation Research Circular
Number E-C058, 2003.
[15] Protection Against Corrosion by Stray Current from Direct Current Systems, BS EN 50162:2004-BSI (British Standards Institution), 2004.
[16] Electrical Safety, Earthing and the Return Circuit. Part 2: Provisions Against the Effects of Stray Currents Caused by DC Traction
Systems, BS EN 50122-2:2010-BSI, 2010.
[17] Standard Practice for Determining Rail-to-Earth Resistance.
American Society for Testing and Material (ASTM) Designation,
G 165-99, ASTM, 1999.

biographies
Saud A. Memon (saud.memon@arup.com) is with Arup, Houston, Texas.

Paul Fromme (p.fromme@ucl.ac.uk) is with the Department of Mechanical Engineering, University College London, United Kingdom.

IEEE Elec trific ation Magazine / s ep t em be r 2 0 1 4

https://www.archive.org/details/

Table of Contents for the Digital Edition of IEEE Electrification Magazine - September 2014