Snow Hill Tunnel
Snow Hill Tunnel is a railway tunnel on the northern edge of the City of London between City Thameslink and Farringdon stations. The tunnel runs beneath the Smithfield meat market and was constructed using the cut and cover method immediately prior to the building of the market. The tunnel opened on 1 January 1866.
Snow Hill tunnel was constructed by the London, Chatham and Dover Railway (LC&DR) to connect its tracks from the Ludgate Viaduct to those of the recently opened Metropolitan Railway's Widened Lines south of Farringdon station. To the north-west, the Widened Lines in turn connected to the tracks of the Great Northern Railway at King's Cross and the Midland Railway at St Pancras via tunnels running beneath the two main line termini. Snow Hill tunnel thus provided the crucial link in the only north-south railway route through central London, enabling cross London passenger and goods services to be run by a number of main line railway companies.
When first opened the tunnel had an additional eastwards connection to the Metropolitan Railway's tracks, enabling trains from the south to also serve Aldersgate (now Barbican) and Moorgate (now Moorgate) stations. The eastward curve also connected to a goods station beneath Smithfield market. The curve and the goods station are no longer in use.
A station, also named Snow Hill, was opened in the tunnel in 1874 providing an interchange with the LC&DR's adjacent terminus at Holborn Viaduct station. Snow Hill station closed in 1916 although the tunnel remained in use for goods traffic until the end of the 1960s. Tracks were lifted in 1971 and the tunnel was abandoned for fifteen years until works began in 1986 to bring the north-south route back into operation as part of the Thameslink route. New tracks were laid and services reopened in 1988.
The southern end of the tunnel was originally adjacent to Holborn Viaduct station, with trains running on viaduct between there and Blackfriars. As part of the Thameslink works, the viaduct was demolished and replaced with a new section of cut and cover tunnel reaching most of the way to Blackfriars, incorporating City Thameslink station. To provide clearance for the new tunnel, the road levels at the western end of Ludgate Hill and in the adjacent junction of Ludgate Circus were raised several feet so that the tunnel could pass below.
A report in 2008 by The Planning Inspectorate into a proposed development of the General Market Building confirms that the tunnel structure, known as the lids, urgently required either repair or replacement. The tunnel lids are supported by girders which have deteriorated due to steam exhaust gases and, more recently, from wet conditions due to failed waterproofing of the decks above. Network Rail confirmed however that the condition of the structure is not dissimilar to many other structures of the same age on the network, and are comfortable that the structure is safe as it currently stands.
- Ludgate Hill railway station - closed station on the viaduct a short distance north of Blackfriars station. It was demolished with the viaduct.
- H.P.White, London Railway History (A regional history of the railways of Great Britain, Volume III - Greater London). David and Charles, 1963 and 1971. ISBN 0-7153-5337-3.
- Report to the Secretary of State for Communities and Local Government, dated 20 May 2008, ref APP/K5030/V/07/1201433-36