Original: All three were replaced by overhead working before World War I. Notes See also Ground-level power supply Kingsway tramway subway Railway electrification system Tramway tracks Third rail External links Article on NYC conduits Illustrated articles on London 's conduits and the Kingsway Tram Subway .
Simplified: Other pages Ground-level power supply Kingsway tramway subway Railway electrification system Tramway tracks Third rail Other websites Article on NYC conduits Illustrated articles on London 's conduits and the Kingsway Tram Subway .