Central line (London Underground) that the transport benefits of a Park Royal station on the Central line are not sufficiently high to justify the costs of construction. Central line (London Underground) The Central line is a London Underground line that runs through central London, from , Essex, in the north-east to and in the west. Coloured red on the Tube map, the line serves 49 stations over , 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,
London Underground 1986 Stock consultation results show that the blue prototype was the favoured, and provided the core design basis for the 1992 Stock that was built for London Underground's Central line and Network SouthEast's Waterloo & City line. London Underground 1986 Stock The London Underground 1986 Tube Stock consisted of three prototype electric multiple units built for London Underground that led to the development of the 1992 Stock. In 1984, London Transport ordered three different prototype trains to test new materials, construction methods and seating layouts. Two were built by Metro-Cammell at its Washwood Heath factory, and the third by British Rail Engineering