|Early developments worldwide|
Electricity was first used on railways for communication. The first example of the use of the electric telegraph was by Brunel on the Great Western Railway between Paddington and West Drayton in 1838. At that time the electric motor had been under development powering small models and a full sized battery–powered locomotive was built. It was, however, seriously flawed, being heavy, unreliable, and of short range.
In 1851 a break-through was made in America where it was demonstrated on a model that the transfer of power to the motor could be along a rail, thus avoiding having to carry the power source on the locomotive. What was needed but not yet available was the ability to generate large volumes of electricity for transmission along lines. Development work on this and on motors continued. Some engineers concentrated on generating the electricity on the power unit, thus creating precursors of the diesel electric locomotive. Others focussed on electric transmission from power stations along rails or wires to an electric motor on the train.
In 1879 Siemens introduced the first practical electric railway operation in Berlin, using a conductor rail. The Volks Electric Railway in Brighton opened in 1884 and is today the oldest electric railway still operating. In 1886 came the Ryde Pier Tramway, and from 1893 the Manx Electric Railway.
In America an important development in 1889 was by Sprague who used overhead wires for distribution and installed motors on the bogies under the passenger cars, rather than in separate locomotives. In America it was the street tramway and inter–urban street-car or tram which were the focus of electric traction development. In Britain it was not until 1901 that electric street tramways were introduced in London, whereas by 1917 there were in America some 60,000 trams operating over 26,000 miles of street tramway.
The Sprague system, as it was called, was applied in America to inter-urban railways from 1897. It used a conductor rail rather than overhead wires as the power requirement was such that there was a need for a high ampage or quantity of current. This system of low voltage direct current (LVDC) distribution is in use today in south east England and elsewhere. It has the advantage of being able to store electricity in batteries on the train to provide greater flexibility of operation, and of offering good acceleration. It came to be known as the ‘London Standard’.
England can lay claim to the first electric underground railway in the world, the City & South London of 1890, now part of the Northern Line followed in 1898 by the Waterloo & City Line. Both were tube railways with small dimension carriages. In 1904 the Great Northern & City Line from Finsbury Park to Moorgate was the first in Britain to use normal surface railway carriages. The first heavy duty electric railways in Britain were the Metropolitan and District Railways in London supplied from 1905 by Lots Road power station. They were followed by the London & North Western and the London & South Western. All these lines were LVDC.
American influence was strong in Britain as it was there that major steps were made to transmit electricity over long distances. Thus in the early 1920s American development of electricity transmission was such that three powers stations in Chicago could produce what it took 77 to produce in London. As these were developed it became possible to transmit to sub-stations using the more efficient alternating current (AC) which was converted on the train to DC by a rectifier. This had the advantage of enabling much longer routes to be operated by electric train.
A detailed Factsheet on early developments worldwide is available here.