The Birmingham, Bristol & 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 (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.