Apart from Bank, which was completely below ground, all stations had buildings designed by Harry Bell Measures. They were single-storey structures to allow for future commercial development above and had elevations faced in beige terracotta. Each station had lifts manufactured by the Sprague Electric Company in New York. The lifts were provided in a variety of sizes and configurations to suit the passenger flow at each station. Generally they operated in sets of two or three in a shared shaft. Station tunnel walls were finished in plain white ceramic tiles and lit by electric arc lamps. The electricity to run the trains and the stations was supplied from the power station at Wood Lane at 5,000V AC which was converted at sub-stations along the route to 550V DC to power the trains via a third rail system.