London Underground in 1994 who inherited the non standard system (for London Underground). The line is still powered from its own substation located in the Waterloo depot. 600 V DC, third rail (top contact) Glasgow Subway, electrified in 1935 250 V DC, third rail (top contact) Hythe Pier Railway, electrified in 1922 110 V DC, third rail (top contact) Volk's Electric Railway was originally electrified at 50VDC, raised to 160V in 1884 and reduced to 110VDC during the 1980s. 100 V DC, four rail The elevated "monorail" at the National Motor Museum, Beaulieu uses rubber tyres running on two metal tracks, one on either side of the central guide. Because it is rubber-tyred, it requires two current conductors and two collectors (hence the four-rail designation). Obsolete systems Great Britain has used different electrification systems in the past. Many of these date from the early part of the 20th century, when traction electricity was in the experimental stage. This section describes each system, in order of decreasing voltage. 6,600V, 25Hz AC, overhead Lancaster to Heysham via Morecambe: Used for an early trial of electrification; opened between 13 April and 14 September 1908. In 1953, it was converted to 50Hz, and operated until 1966. 'Elevated Electric' London suburban lines of the London, Brighton and South Coast Railway (LBSCR): The first large-scale suburban electrification scheme; starting with the South London Line and then extended to other commuter lines around the south of London, operational from 1 December 1909. Following the grouping into the LBSCR into the Southern Railway in 1922, all of the 6,600V lines were converted to the 650VDC third rail system by September 1929. 6,250V 50 Hz AC, overhead During the initial electrification of parts of the network to 25kV50HzAC overhead, the initial solution to the limited clearance problems in suburban areas (due to numerous tunnels and bridges) in London and Glasgow was to use the lower voltage of 6.25kV. Later technological improvements in insulation allowed these areas to be converted to 25kV. The last sections of 6.25kV were converted during the 1980s. London, Tilbury and Southend Lines The 6.25kV section was from Fenchurch Street to beyond Barking, with changeovers there on both the Upminster and Tilbury lines. The section between and was also at 6.25kV. The remainder was at 25kV. The sections electrified at 6.25kV were converted to 25kV during the early 1980s. Great Eastern Lines The line from Liverpool