The story
The 19th century saw the invention of the modern railway and their rapid expansion into national networks in Europe and worldwide. During this period motive power was confined to steam locomotives, some of which by mid-century were capable of top speeds of 80 miles per hour (130 km/h), with average express journey speeds of 50–60 mph (80–97 km/h).
The 1880s saw the development of electric power and its application to rail transport. Electric power offered several advantages over steam; it is more efficient, allowing more rapid acceleration, and a higher power output when necessary. Its disadvantage is the high initial cost of the infrastructure involved, such as the power production and distribution system needed.
1879 saw the demonstration of an experimental system by Werner von Siemens in Berlin, which was followed by an electric tramway at Lichterfelde, in 1881, and heavy rail applications in 1890 (the City and South London Railway) and 1895 (the Baltimore Belt Line).
Most electric trams and railways used DC power which had limitations. To study the possibilities of AC, for the upcoming
Three-phase AC railway electrification that started in mountain areas of Switzerland and Italy, in 1899 a consortium of ten of the largest and wealthiest companies in Germany joined to form the "Research Association for High-speed Electric Railways"(Studiengesellschaft für elektrische Schnellbahnen, or St.E.S.) to examine the possibilities of high-speed electric rail travel.
From Wikipedia’s article on Experimental three-phase railcar, shared under CC BY-SA 4.0.3