Earth-leakage problems and solutions on the Tyne and Wear Metro

The interference and corrosion effects of stray traction-return currents flowing through the earth have presented DC track-return railway operators and public utilities with problems for almost a century. The paper discusses the nature of these problems and the steps taken to include measures in the design and construction of the Tyne and Wear Metro to reduce them to acceptable levels. The formation and work of the Corrosion Working Party is explained, together with the problems encountered and solutions applied during the early years of the Metro operation. Conclusions are drawn and design guidelines set in the light of experience to date