Whilst rail infrastructure offers genuine benefits to improving the economic performance and appeal of a given area it can also present a significant threat. Any rail system that is powered by Direct Current (DC) has the potential to cause corrosion of sub-surface metalwork (such as metallic pipes, structural reinforcing, or other such electrically conductive metalwork) by discharging through it as a path of least electrical resistance.
An integral part of the problem of stray current is that electricity is invisible, and when it comes to this variety of the problem it is occurring beneath the ground, a problem that cannot be seen in a place that you can’t see it. As a result of the difficulty in identifying areas which are suffering due to stray current corrosion it is very common for it only to be discovered when the damage is already at an advanced stage.