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
London Bridge – Greenwich Railway Viaduct London Bridge – Greenwich Railway Viaduct The London Bridge – Greenwich Railway Viaduct consists of a series of nineteen brick railway viaducts linked by road bridges between London Bridge railway station and Deptford Creek, which together make a single structure in length. The structure carries the former London and Greenwich Railway line and consists of 851 semi-circular arches and 27 skew arches or road bridges. It is the longest run of arches in Britain, It is also one of the oldest railway viaducts in the world, and the earliest example of an entirely elevated railway line. It was built between