<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Central line is a London Underground line that runs through central London, from Epping, Essex, in the north - east to Ealing Broadway and West Ruislip in the west . Coloured red on the Tube map, the line serves 49 stations over 46 miles (74 km), which makes it the longest Tube line . It is also one of only two lines on the Underground network to cross the Greater London boundary, the other being the Metropolitan line . One of London's deep - level railways, Central line trains are smaller than those on British main lines . </P> <P> The line was opened as the Central London Railway in 1900, crossing central London on an east--west axis, as the third deep - level Tube line to be built after electric trains made them possible . It was later extended to the western suburb of Ealing . After the Second World War, the line was expanded considerably into the recently - constructed suburbs, taking over steam - hauled outer - suburban routes to the borders of London and beyond to the east . This realised plans that had been delayed by the war, when construction stopped and the unused tunnels were used as air - raid shelters and factories . However, suburban growth proved to be less than expected, and of the planned expansions one (to Denham, Buckinghamshire) was cut short due to its location in the Metropolitan Green Belt and another (to Ongar) ultimately closed in 1994 due to low patronage . The Central line has mostly been operated by automatic train operation since a major refurbishment in the 1990s, although all trains still carry drivers . Many of its stations are of historic interest, from turn - of - the - century Central London Railway buildings in west London to post-war modernist designs on the West Ruislip and Hainault branches, as well as Victorian - era Eastern Counties Railway and Great Eastern Railway buildings east of Stratford, from when the line to Epping was a rural branch line . </P>

Essex town used to house the terminus of the london underground