The Severn railway tunnel is the longest main line railway tunnel in Britain and carries the former Great Western Railway line between Wales and England under the River Severn estuary. Construction started in 1873 and it was opened in 1886; the tunnel runs for some 7km between Caldicot and Pilning. Sudbrook Village (nprn 308285) was established on the Welsh side to house the construction workers and a permanent pumping station erected there (nprn 34970) to drain the water from the tunnel.
B.A.Malaws, RCAHMW, 24 April 2003.