Feltham marshalling yard, also known as Feltham hump yard, was a large railway marshalling yard designed for the concentration of freight traffic to and from South West London, and for transfer to other marshalling yards in London. It was built on the Waterloo to Reading Line. It opened in 1918 and was closed by British Railways on 6 January 1969.
During the early years of the twentieth century the London and South Western Railway (LSWR) experienced a substantial growth in its freight traffic to and from London, and for transfer to other railways. By 1910 this traffic was beginning to overwhelm the existing facilities at Nine Elms. Plans were therefore made for a hump marshaling yard and motive power depot at Feltham. The purchase of 41.5 acres (16.8 hectares) of land was confirmed in 1911, with additional land being purchased in 1915. This location gave excellent access to the company main lines as well as direct links to the Great Western Railway and London and North Western Railway, and to the Midland Railway, Great Northern Railway and Great Eastern Railway via the North London line. The plans were confirmed on 30 March 1916, and work started soon after with the help of around 200 German prisoners of war. The first nine ‘down’ sidings were opened on 9 December 1917 and the remainder by 2 October 1921.
The yard was completed in 1921 and incorporated two gravity shunting humps and equipped with the latest automated technology including electrically operated points, and widespread use of Track circuits. With its 32 miles (51 km) of track, (the longest siding being 1,662 feet or 507 metres in length and the shortest being 1,331 feet or 406 metres), it could handle 2500 wagons a day. These were brought in by 50 down and 26 up trains, and being removed by 18 down and 46 up services. This was, probably, the busiest marshalling yard in the country at that time. Up to 3390 wagons could be sorted per day and an incoming train of wagons could be sorted in 12 minutes.