Catalogue description Great Western Railway Company: Severn Tunnel Papers

The construction of the Severn Tunnel was authorised by the Severn Tunnel Railway Act 1872, the promotion of which was undertaken by the Great Western Railway Company (GWR). The act authorised the construction of a railway commencing at a junction with the Bristol and South Wales Union Railway at Almondsbury, Gloucestershire to a junction with the South Wales Railway at Rogiet, Monmouth, the length of which would be just over seven miles and seven furlongs. Of this length, four and a half miles would be in tunnel.

Work was commenced on 18 Mar 1873 and the first special train carrying Sir Daniel Gooch (Chairman of the GWR), his wife and friends travelled through the tunnel on 5 Sept 1885. The opening for normal traffic was delayed because the pumping station at Sudbrook (which drains the tunnel) had not been fully completed and a large Guibal fan to ventilate the tunnel had yet to be installed. When this work was finished, the first goods train services started using the tunnel on 1 Sept 1886. The passenger services began on 1 Dec 1886.