Wimbledon, London Spencers attempted to get parliamentary permission to enclose the common as a new park with a house and gardens and to sell part for building. Following an enquiry, permission was refused and a board of conservators was established in 1871 to take ownership of the common and preserve it in its natural condition. Transport links improved further with railway lines to Croydon (Wimbledon and Croydon Railway, opened in 1855) and Tooting (Tooting, Merton and Wimbledon Railway, opened in 1868). The District Railway (now the London Underground District line) extended its service over new tracks from Putney in 1889. In the
London Underground infrastructure Tube Programme, investigating replacing the trains for the Bakerloo and Piccadilly lines, is looking for trains with better energy conservation and regenerative braking. The Underground serves 270 stations. Fourteen Underground stations are outside Greater London, of which five (Amersham, Chalfont & Latimer, Chesham, and Chorleywood on the Metropolitan line and Epping on the Central line) are beyond the M25 London orbital motorway. The longest distance between two stations is between Chalfont & Latimer and Chesham on the Metropolitan line. The shortest distance between adjacent stations is the between Leicester Square and Covent Garden on the Piccadilly line. The station furthest