Mersey Railway Electrification

May 31, 1902 saw the Mersey Railway inaugurate full electric operations between Liverpool and Birkenhead, replacing steam locomotives in the underwater tunnel. Engineers from British Westinghouse installed third-rail systems and new multiple-unit trains, overcoming ventilation and smoke issues that had plagued passengers. This innovation was among Britain's earliest mainline electrifications and demonstrated the superiority of electric power for urban and tunnel operations. It boosted ridership significantly and set precedents for later London Underground extensions. The change reflected the Edwardian era's push toward modern urban transit amid growing city populations.