Stray current is for life-not just for Christmas. Stray current corrosion management strategies for DC traction systems

The construction of a new light rail or tramway in an urban landscape presents a series of corrosion risks to an often densely-packed buried utility infrastructure. The corrosion risk does not simply go away once the system has been built, commissioned and de-snagged, but continues unseen in the background. Good inspection and testing practices at the start of the railway's life may reduce the chances of major pipeline and cable failures to a very low level but unless the railway is well-maintained unexpected corrosion failures may start to occur several years later. Whilst such failures may lead to minor (utility) service disruption, more catastrophic failure can also occur with severe consequences. Good control of stray current is also of direct benefit to the railway; it reduces rail corrosion and reduces infrastructure corrosion. This paper addresses the corrosion management issues surrounding the addition of a tramway into a previously tramfree environment.