West London line

The West London line (WLL) is a railway line in inner West London that links Willesden Junction in the north to Clapham Junction in the south. The line has always been an important cross-London link, especially for freight services. Southern and London Overground provide regular passenger services; detailed below.

In November 2024, the London Overground service on the line was named, along with that on the North London line, the Mildmay line (to honour the Mildmay Mission Hospital which treated victims of the HIV/AIDS crisis in the 1980s) and coloured light blue on the Tube map.

The Birmingham, Bristol and Thames Junction Railway was authorised in 1836 to run from the London and Birmingham Railway (L&BR), near the present Willesden Junction station, across the proposed route of the Great Western Railway (GWR) on the level, to the Kensington Canal Basin. For about twelve years, the railway ran alongside the Kensington Canal, formerly Counter's Creek, a minor tributary of the Thames River until it was filled in, the water course turned into a sewer and the future District line built over it. Construction was delayed by engineering and financial problems. Renamed the West London Railway (WLR) the line officially opened on 27 May 1844, and regular services began on 10 June, but before that trials to demonstrate the potential of the atmospheric railway system had been held from 1840 to 1843 on a half-mile section of track adjacent to Wormwood Scrubs, leased to that system's promoters; The WLR used conventional power but was not a commercial success. After only six months it closed on 30 November 1844.

The London and Birmingham Railway Act 1845 (8 & 9 Vict. c. clvi) authorised the GWR and the L&BR (which became part of the London and North Western Railway [LNWR] in 1846) to take a joint lease of the WLR. The line was used only to carry coal, and passenger service was not re-introduced. The lack of success of the line became such a regular target of Punch magazine that the line was called Punch's Railway.

The West London Extension Railway Act 1859 (22 & 23 Vict. c. cxxxiv) granted those two companies, with the London, Brighton and South Coast Railway (LB&SCR) and the London and South Western Railway (L&SWR), powers to construct the West London Extension Joint Railway on the filled-in canal south from the Kensington Basin to the bridge under the Kings Road, to bridge the Thames and to connect near Clapham Junction to railways south of the river. The existing line was doubled, and the flat crossing of the GWR main line, where a number of collisions had occurred, was replaced by a flyover. The new line opened on 2 March 1863 with a passenger station at Addison Road (now Kensington (Olympia)) slightly north of the original Kensington station, and was then well used by various inner London services for the remainder of the nineteenth century.

For a time, the West London line formed part of the GWR's Middle Circle route (1872–1905) which ran (clockwise) from Mansion House to Aldgate (originally Moorgate) via Earl's Court, Kensington Olympia, Latimer Road and Baker Street. The West London line was also part of London Underground for a time and operated as a branch of the Metropolitan Railway between Edgware Road and Addison Road. The branch was eventually closed and the link between the West London line and today's Hammersmith & City line was dismantled in 1930.

A branch was installed to allow trains from the former Southern Railway to access to the West Coast Main Line and vice versa: in summer the London Midland and Scottish Railway ran from as far north as Glasgow to the South Coast. Through trains in the steam era changed locomotives here. From the 1920s there was a United Dairies depot on the site of a former dairy farm here, which up until the late 1970s had regular milk train deliveries.

The northern section of the line, from Willesden Junction to Kensington Olympia and on to Earls Court, was electrified by the LNWR in 1915.