The South Wales Main Line is a branch of the Great Western Main Line in the UK. It diverges from the main line at Wootton Bassett near Swindon, first calling at Bristol Parkway, after which the line continues through the Severn Tunnel into South Wales. High speed trains (known as InterCity 125 trains in the days of British Rail) usually terminate at Swansea, where there are connections to West Wales, but an occasional train runs from Paddington through Swansea to Carmarthen.
History of the line
The original route of the Great Western Railway between London and South Wales left the Bristol-bound Great Western Main Line at Swindon, proceeding via Stroud, Gloucester and Chepstow before rejoining the line as we know it today at Severn Tunnel Junction. This gave rise to the nickname 'Great Way Round'.
In 1886, the opening of the Severn Tunnel brought the opportunity of a more direct route to South Wales, and trains from Swindon to Newport and beyond were routed via Bristol and the Severn Tunnel. This route leaves the one we know today at Wootton Bassett near Swindon rejoining it close to Patchway station.
The route used today was established in 1903 with the building of what is often known as the Badminton Line. This involved the construction of about 33 miles of new track including two tunnels at Alderton and Sodbury between Wootton Bassett and Patchway. Not only did this provide a more direct route for traffic to and from South Wales, the gradient was easier for coal trains to negotiate, and it was perceived that the line would be a boost to what was, at the time of building, the expanding port of Fishguard, which was the GWR's connection to a point of departure for the United States of America by liner.
Services on the line include First Great Western's InterCity express services between Swansea and London Paddington. A regional service, branded Swanline, operates between Swansea and Cardiff.
South Wales Main Line - Stations (from east to west)