South Wales Main Line

From TrainSpottingWorld, for Rail fans everywhere
South Wales Main Line
Stations (from east to west)

for Golden Valley Line
for Great Western Main Line
Bristol Parkway
Severn Tunnel Junction
for Gloucester to Newport Line
for Gloucester to Newport Line
for Welsh Marches Line
Cardiff Central
for Cardiff City Line
for Coryton Line
for Maesteg Line
for Merthyr Line
for Rhondda Line
for Rhymney Line
for Vale of Glamorgan Line
for Maesteg Line
for Vale of Glamorgan Line
Port Talbot Parkway
Briton Ferry
for Heart of Wales Line
for West Wales Line

See also: Transport in Wales

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.

Places served

The line serves the following cities and towns (towns in bold are served by high speed train services):


Wikimedia Commons
has media related to:
South Wales Main Line
  • Kevin Robertson and David Abbott (1988). GWR The Badminton Line. Sutton Publishing Ltd. 

Railway lines in Wales:
Main lines:  Gloucester-Newport Line   North Wales Coast Line   Shrewsbury-Chester Line   South Wales Main Line   Welsh Marches Line 
Valley lines:           Butetown Branch            City Line            Coryton Line            Ebbw Valley Line            Maesteg Line 
          Merthyr Line            Rhondda Line            Rhymney Line            Vale of Glamorgan Line 
Rural lines:  Borderlands Line   Cambrian Line   Conwy Valley Line   Heart of Wales Line   West Wales Line 

Railway lines in South-West England and the "Great Western" zone :
Main lines:  Cross-Country Route   Great Western Main Line
 Cherwell Valley Line   Gloucester-Newport Line   Exeter-Paignton "Riviera" Line   South Wales Main Line  
 Wessex Main Line   West of England Main Line   
Commuter lines:  Severn Beach Line   Slough-Windsor & Eton Line
Rural lines:  Exeter-Barnstaple "Tarka" Line   Exeter-Exmouth "Avocet" Line   Golden Valley Line   Heart of Wessex Line  
 Henley Branch Line   Looe Valley Line   Marlow Branch Line   Par-Newquay "Atlantic Coast" Line  
 St Ives Bay Line   Tamar Valley Line   Truro-Falmouth "Maritime" Line