South Wales Main Line

The South Wales Main Line (Welsh: "Prif Reilffordd De Cymru") 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.

Local services in Wales are operated by Arriva Trains Wales, with express trains from London provided by First Great Western. East of, and including, Cardiff some services are also provided by CrossCountry, along with First Great Western local services to Bristol and the South Coast.__TOC__

History

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.

Infrastructure

There are four tracks from Severn Tunnel Junction through Newport to Cardiff Central, with two tracks on the remaining sections. Multiple-aspect signals are controlled from several power signal boxes including Swindon, Bristol, Newport and Cardiff.

The line speed from London to the Severn Tunnel is 125 mph (200 km/h), and 90 mph (144 km/h) from Severn Tunnel to Swansea, although lower restrictions apply at various locations. There are plans to raise the speed in Wales following upgrading of track and signals.

Associated routes

Immediately west of Bristol Parkway is a complex of junctions that allow trains to leave and join the main line to South Wales. Trains from London to Bristol Temple Meads can run via the Badminton Line and Filton Abbey Wood, while trains from South Wales can use a curve between Patchway and Filton. The majority of these continue on the Wessex Main Line to Portsmouth, but some trains to London also use this route.

An alternative diversionary route exists for when the Severn Tunnel is closed. This takes trains from Severn Tunnel Junction to Gloucester, from where they can rejoin the main line either by using the Golden Valley Line to Swindon, or by using the Cross-Country Route and reversing at Bristol Parkway.

If the line is closed between Cardiff Central and Bridgend, an alternative route exists along the Vale of Glamorgan Line.

Some trains continue beyond Swansea onto the West Wales Line to Carmarthen. On the other hand, 50% of services terminate at Cardiff Central during peak hours.

The local service between Swansea and Cardiff is branded Swanline and those within Cardiff and to surrounding towns, including on the Maesteg Line, are referred to as Valley Lines.

Future plans

Traffic levels on the Great Western Main Line are rising faster than national average, with continued increases predicted. The now defunct Strategic Rail Authority produced a Route Utilisation Strategy for the Great Western Main Line in 2005 to propose ways of meeting this demand, Network Rail plan to implement a new study in 2008. In the meantime, their 2007 Business Plan includes the provision of extra platform capacity at Cardiff Central, Newport and Bristol Parkway, also resignalling and line speed improvements in South Wales, most of which would be delivered in 2010-2014.

Communities served

Towns and cities served by trains from London:
* London
* Reading
* Didcot
* Swindon
* Bristol
* Newport
* Cardiff
* Bridgend
* Port Talbot
* Neath
* Swansea

Towns and cities served by local trains only:
* Patchway
* Pilning
* Magor
* Rogiet
* Pontyclun
* Pencoed
* Pyle
* Baglan
* Briton Ferry
* Skewen
* Llansamlet
* Llanharan

ee also

* Transport in Wales
* Transport in England

References

*
*
* [http://www.networkrail.co.uk/browse%20documents/BusinessPlan2007/PDF/Route%2013%20Great%20Western%20Main%20Line.pdf 2007 Business Plan] , Network Rail, London
* [http://www.firstgreatwestern.co.uk/Documents/Custom/Timetables/December%202006/Book%20A%20REVISED%20(London,%20Cheltenham,%20Bristol,%20South%20Wales,%20Somerset).pdf First Great Western timetable] for passenger services on South Wales Main Line, Dec 2006—May 2007
* [http://www.firstgreatwestern.co.uk/Documents/Custom/Timetables/May%2007/Book%20A/Lon-South%20Wales.pdf First Great Western timetable] for passenger services on South Wales Main Line, May—Dec 2007
* [http://news.bbc.co.uk/1/shared/spl/hi/pop_ups/06/uk_brunel0s_work_in_south_wales/html/4.stm, BBC News, Flying Arches, Llansamlet]