Southern Electric History and Infrastructure Part 1 - Origins
The third rail low voltage system adopted by the London & South Western Railway for its initial surface electrication followed the system it used for its Waterloo & City underground line between Waterloo and Bank. In turn, the Waterloo & City project was influenced by the City & South London tube line - the catalyst for the Southern Electric.
Opened in 1890, the City & South London Railway was the worlds first deep level underground railway, running from Stockwell initially to the King William Street terminus, reaching Euston in sections by 1907. The commercial success of City & South London Railway influenced the London & South Western Railway over its Waterloo & City tube line leading in turn to the adoption of low voltage dc surface electrification. The City & South London Railway is now forms part of today's City branch of the London Underground Northern Line while the W&C is operated as an isolated branch off the London Underground Central line. Originally the City & South London Railway was worked by small four wheel electric locomotives hauling totally enclosed cars. 52 locomotives were built in total and following reconstruction works in 1922 two were preserved. No.26, built c.1900 by Crompton, was held at Moorgate station but broken up following damage in a 1940 air raid. One of the original batch of fourteen locomotives built c.1889 by Mather & Platt was preserved and today is part of the London Transport collection. This machine is numbered "1" but is known not to be the original No.1. Recent research suggests it is No.13.
Opened in 1898 under London & South Western Railway auspices, the Waterloo & City line followed the low voltage dc principle to the City & South London line. Rolling stock was US built, with Siemens of Germany supplying the electrical equipment. Electric power was supplied from a purpose built power station for which a four wheel electric locomotive was built to for underground shunting of coal wagons. The line was re-equipped in 1940 by English Electric built cars which survived until 1993 when identical cars to those on order for the LU Central Line were delivered to Network South East. Subsequently, the route passed to LU ownership. The small electric shunter and one of the 1940 tube cars survive in the National Railway Museum collection.
Around the turn of the century the steam operated surface railway companies suffered intense competition from the new electric street tramways. The London & South Western Railway, District Railway, Metropolitan Railway and London & North Western Railway each considered and adopted low voltage direct current electrification schemes and those selected routes largely survive today as sections of the areas served South West Trains, the District and Metropolitan lines of London Underground, and the London Overground. In 1899 the District and Metropolitan companies co-operated on electric traction experiments between Earls Court and Kensington High Street stations. This was followed by a 600V dc third and fourth rail electrification by the District Railway between Whitechapel and Ealing in 1905, later reaching Richmond and Wimbledon, followed by the London & North Western Railway to Richmond.
The London & South Western Railway in 1912 adopted a proposal for a 47 mile third rail dc electrification from Waterloo to the Hampton Court and Shepperton branches and the Kingston and Hounslow loops with power supplied from a purpose built power station at Wimbledon. 84 three coach electric units were converted from former steam hauled suburban sets from c.1904. Each three car set was formed of two driving motor coaches flanking a trailer second, although with varying passenger accomodation due to the conversion from steam stock. Each motor coach was powered by two 275 hp Metropolitan Vickers traction motors while an all electric relay multiple unit system supplied by the same company enabled operating of longer trains under the control of a single driver. These trains set the standard for what later became the Southern Electric. Waterloo to Wimbledon via East Putney commenced electric operation in 1915 with Shepperton and Hampton Court completed the following year.
The London Brighton & South Coast Railway adopted a very different electrification system. Using another German concern, this time AEG, as the electrical contractor using power supplied by the local authority. Following testing on the South London line in 1909 public services commenced there and to Crystal Palace by 1911. A high voltage distribution system of 25Hz at 6666.66V was used which by 1925 the overhead system had reached Coulsdon and Sutton.
In 1901 the separate London Chatham & Dover Railway and South Eastern Railway came under the single management control of the South Eastern & Chatham Railway. It considered various proposals before the outbreak of World War I but it was not until 1919 that the SECR decided to adopt a third and fourth rail dc system. A side contact system of 3000V differential with +1500V on the outer third rail and -1500V on the inner fourth rail was planned. Power would come from a dedicated generating station at Angerstein Wharf. Routes planned for electrification were from the Charing Cross, Cannon Street, Holborn Viaduct and Victoria London terminals to all routes to Dartford, and to Addiscombe, Oprpington, Hayes and Bromley North. However this scheme did not come to fruition.
The position around 1920 therefore was that there were 3 different railway companies - London & South Western Railway, South Eastern & Chatham Railway and the London Brighton & South Coast Railway - with 3 different electrification systems in operation or proposed: 660V dc third rail, 3000V dc third and fourth rail and 6666.66V ac overhead. In 1920, a technical committee recommended adoption of a UK standard electrification using either 1500V dc overhead or third rail. Exemptions were that the London Brighton & South Coast Railway company would be allowed to extend its ac system to the south coast, and 750V dc would be permitted where appropriate. This did little for standardisation for the forthcoming Southern grouping as in effect there were sufficient dispensations to continue with all three systems.