Piccadilly line

The original Piccadilly Line - from Finsbury Park to Hammersmith - was formed by merging three separate proposals. From east to west, these were: The Great Northern & Strand Railway, from Wood Green to Aldwych, located underneath the GNR main line between Wood Green and King's Cross. The Brompton & Piccadilly Circus Railway, from Air Street (near Piccadilly Circus) to a point near South Kensington. The Deep Level District, a proposal by the Metropolitan District Railway to build an express tube under its line from just east of Earl's Court to Mansion House, with an intermediate station at Embankment; electric locos would take over the trains from steam ones at Earl's Court. The District purchased the B&PCR in 1898. In 1901 the Yerkes Group took over all three companies before any construction had been started and combined the three proposals into the Great Northern, Piccadilly & Brompton Railway (though in day-to-day use this was quickly abbreviated to the Piccadilly Railway or the Piccadilly Tube). The B&PCR route had already been altered by the District at the west end so as to meet the DLD at South Kensington (with a sharp curve), and was now altered at the east end to meet the GN&SR at Holborn. The planned DLD route was extended in the west to emerge at Barons Court and was abandoned east of South Kensington once it became clear that the Piccadilly combined with an electrified District could handle the traffic. In the eastbound direction the junction was at the east end of the platform and the wider tunnel at this point is still visible. In the westbound direction a separate DLD platform tunnel was built with the junction just west of the station. This tunnel was never used in passenger service. During World War I it was used to store art from the Victoria & Albert Museum and china from Buckingham Palace. From 1927 to 1939 it was used as a signalling school and was also fitted out with track for teaching trainee drivers. In World War II it contained equipment to detect bombs falling in the Thames. Finally, when the station was converted from lifts to escalators in 1971-4, the tunnel became part of the passageways to the Piccadilly Line platform. Also in the 1930s, the District Line was suffering congestion on its city section, which was being fed from the west by no less than 5 branches plus the Circle. Therefore the Piccadilly was extended over two of these (to Hounslow and to Uxbridge), giving a second outlet for the traffic. (Note that, although the dates of this extension are as shown below, from 1932-02-08 the new Piccadilly Line stock being delivered started running on local services between Acton Town - or possibly South Acton - and both Hounslow and South Harrow.) The original layout between the tube mouths (at Barons Court) and Hammersmith had the Piccadilly tracks on the north side of the District; both this section and the tracks westwards to Acton Town were now rearranged, with the Piccadilly Line running between the District tracks. West of Acton Town, the District continued to serve the Hounslow branch until 1964, but on the line to Uxbridge the District service was immediately completely replaced by the Piccadilly as far as South Harrow and later - after the formation of London Transport - the rest of the way (the original powers to run beyond South Harrow applied explicitly to the MDR, and the Yerkes group were unwilling to take the legal risk of running any other trains that way). During World War II, the closed station at Down Street was converted into the headquarters of the Railway Executive - the body that controlled all railways during and immediately after the war. Walls were built along the platform edges, and the resulting space was converted to offices. Access was normally from the surface, but trains could also be stopped to allow people in and out of the driver's cab. Brompton Road was also converted and used for London Anti-Aircraft Control; later it was a Territorial Army training centre a