STRAY CURRENT CONTROL USING THE RAIL BOOT

The electrical isolation of the rails of DC powered transit systems from earth has been necessary for the reduction in stray earth current and the corrosion of the rail and surrounding utilities it causes. All systems presently under consideration and constructed over the past 20 years have utilized some type of electrical rail isolation for stray current control. This paper looks at the advances made in rail boot over the past 5 years, the various cross sections in use, the electrical data collected, construction and installation techniques, shipping and handling, test data, and the mechanical properties of the system. The information gathered for this paper comes from tests conducted over the past 5 years dating back to installations of rail boot installed over 10 years ago. All testing has been conducted on light rail systems in North America and indicates that the rail boot material which has been used extensively shows a high level of variability in its resistance to earth levels based on the cross section used and the construction and construction inspection surrounding the installation.