Its natural ally seemed to be the Great Western Railway. With other lines it formed a route between the mineral resources of South Wales and the industries of the north-west of England, and this attracted the interest of the London and North Western Railway, which sought access to South Wales. The GWR and the LNWR jointly leased the S&HR line in 1862, later jointly acquiring ownership of it, in 1871. LNWR mineral traffic developed, and after the opening of the Severn Tunnel in 1886, the line became an important main line for traffic from the south-west of England to the north-west.
