The South Wales Main Line (), originally known as the London, Bristol and South Wales Direct Railway or simply as the Bristol and South Wales Direct Railway, is a branch of the

Great Western Main Line The Great Western Main Line (GWML) is a main line railway in England that runs between London Paddington and . It connects to other main lines such as those from Reading to Penzance and Swindon to Swansea. The GWML is presently a part of t ...

in Great Britain. It diverges from the core London-Bristol line at

Royal Wootton Bassett Royal Wootton Bassett , formerly Wootton Bassett, is a market town and civil parish in Wiltshire, England, with a population of 13,570 at the 2021 Census. In the north of the county, it lies to the west of the town of Swindon and northeast of ...

beyond

Swindon Swindon () is a town in Wiltshire, England. At the time of the 2021 Census the population of the built-up area was 183,638, making it the largest settlement in the county. Located at the northeastern edge of the South West England region, Swi ...

, first calling at Bristol Parkway, after which the line continues through the

Severn Tunnel The Severn Tunnel () is a railway tunnel in the United Kingdom, linking South Gloucestershire in the west of England to Monmouthshire in south Wales under the estuary of the River Severn. It was constructed by the Great Western Railway (GWR) be ...

into

South Wales South Wales ( ) is a Regions of Wales, loosely defined region of Wales bordered by England to the east and mid Wales to the north. Generally considered to include the Historic counties of Wales, historic counties of Glamorgan and Monmouthshire ( ...

. Much of the South Wales Main Line was built between the 1830s and 1886; originally trains to and from destinations in England ran via

Chepstow Chepstow () is a town and community in Monmouthshire, Wales, adjoining the border with Gloucestershire, England. It is located on the tidal River Wye, about above its confluence with the River Severn, and adjoining the western end of the ...

Gloucester Gloucester ( ) is a cathedral city, non-metropolitan district and the county town of Gloucestershire in the South West England, South West of England. Gloucester lies on the River Severn, between the Cotswolds to the east and the Forest of Dean ...

and

Stroud Stroud is a market town and civil parish in Gloucestershire, England. It is the main town in Stroud District. The town's population was 13,500 in 2021. Sited below the western escarpment of the Cotswold Hills, at the meeting point of the ...

, joining the Great Western Main Line at Swindon. A more direct route was challenging yet desirable, leading to the construction of the line's most prominent civil engineering feature, the

. Completed in 1886, it permitted a significant reduction in journey times between various destinations, especially after the construction of the Badminton Line in 1903. During the

British Rail British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most rail transport in Great Britain from 1948 to 1997. Originally a trading brand of the Railway Executive of the British Transport Comm ...

era, the line was incorporated into the

Western Region Western Region or West Region may refer to: Places *Al Gharbia, Abu Dhabi, the Western Region *Western Region, Bahrain * Western Region, Eastern Cape, South Africa *Western Region, Ghana *Western Region (Iceland) *Western Region, Nepal *Western Reg ...

and

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, Fuel oil, oil or, rarely, Wood fuel, wood) to heat ...

s were replaced by

diesel locomotive A diesel locomotive is a type of railway locomotive in which the prime mover (locomotive), power source is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is con ...

s, such as the

Intercity 125 The InterCity 125 (originally Inter-City 125) or High Speed Train (HST) is a diesel-powered High-speed rail, high-speed passenger train built by British Rail Engineering Limited between 1975 and 1982. A total of 95 sets were produced, each com ...

high speed trainsets. During the 2010s, the line between Swindon and Cardiff Central was electrified using the 25 kV AC overhead system as part of the wider electrification of the Great Western Main Line; this has permitted the operation of electric traction between Cardiff and London for the first time to commence in 2020. Presently,

Great Western Railway The Great Western Railway (GWR) was a History of rail transport in Great Britain, British railway company that linked London with the southwest, west and West Midlands (region), West Midlands of England and most of Wales. It was founded in 1833, ...

operates Class 800 trains between London and South Wales, and "Castle class" High Speed Trains on services between

Cardiff Cardiff (; ) is the capital city, capital and List of urban areas in the United Kingdom, largest city of Wales. Cardiff had a population of in and forms a Principal areas of Wales, principal area officially known as the City and County of Ca ...

and

South West England South West England, or the South West of England, is one of the nine official regions of England, regions of England in the United Kingdom. Additionally, it is one of four regions that altogether make up Southern England. South West England con ...

CrossCountry CrossCountry (legal name XC Trains Limited) is a British train operating company owned by Arriva UK Trains, operating the current CrossCountry franchise. The CrossCountry franchise was restructured by the Department for Transport (DfT) in 2006, ...

provides services from Cardiff to

Nottingham Nottingham ( , East Midlands English, locally ) is a City status in the United Kingdom, city and Unitary authorities of England, unitary authority area in Nottinghamshire, East Midlands, England. It is located south-east of Sheffield and nor ...

via

Severn Tunnel Junction The River Severn (, ), at long, is the longest river in Great Britain. It is also the river with the most voluminous flow of water by far in all of England and Wales, with an average flow rate of at Apperley, Gloucestershire. It rises in t ...

and thence the

Gloucester to Newport Line Gloucester ( ) is a cathedral city, non-metropolitan district and the county town of Gloucestershire in the South West of England. Gloucester lies on the River Severn, between the Cotswolds to the east and the Forest of Dean to the west; it is ...

via

and

Birmingham Birmingham ( ) is a City status in the United Kingdom, city and metropolitan borough in the metropolitan county of West Midlands (county), West Midlands, within the wider West Midlands (region), West Midlands region, in England. It is the Lis ...

Transport for Wales Transport for Wales (TfW; ; ) is a not-for-profit company owned by the Welsh Government and managed at arms length by its appointed board. TfW oversees the Transport for Wales Group (TfW Group) consisting of itself and its subsidiaries: Trans ...

operates services between South Wales and North Wales via the English Midlands on the line. Operations are mostly managed from the Wales Rail Operating Centre in Cardiff; digital signalling is to be rolled out.

History

The

South Wales Railway The South Wales Railway () was a main line railway which opened in stages from 1850, connecting the Great Western Railway from Gloucester to South Wales. It was constructed on the broad gauge. An original aspiration was to reach Fishguard to eng ...

was built to carry traffic from

to the strategic port of

Milford Haven Milford Haven ( ) is a town and community (Wales), community in Pembrokeshire, Wales. It is on the north side of the Milford Haven Waterway, an estuary forming a natural harbour that has been used as a port since the Middle Ages. The town was ...

and capture the lucrative

transatlantic Transatlantic, Trans-Atlantic or TransAtlantic may refer to: Film * Transatlantic Pictures, a film production company from 1948 to 1950 * Transatlantic Enterprises, an American production company in the late 1970s * ''Transatlantic'' (1931 film) ...

maritime trade as well as communication with

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

.MacDermot 1927, pp.556–558.Ernie Shepherd, ''Fishguard and Rosslare Railways and Harbours Company: An Illustrated History'', Colourpoint Books, Newtownards, 2015, At Gloucester, the South Wales Railway met with the

(GWR) which formed a route between London and South Wales after the opening of

Brunel Isambard Kingdom Brunel ( ; 9 April 1806 – 15 September 1859) was an English civil engineer and mechanical engineer who is considered "one of the most ingenious and prolific figures in engineering history", "one of the 19th-century engi ...

Chepstow Railway Bridge Chepstow Railway Bridge was built to the instructions of Isambard Kingdom Brunel in 1852. The "Great Tubular Bridge" over the River Wye at Chepstow, which at that point forms the boundary between Wales and England, is considered one of Brunel's ...

in 1852. The original route of the GWR left the Bristol-bound

, proceeding via

and

before rejoining the present line at

; this circular route gave rise to the nickname 'Great Way Round'. GWR officials realised that the journey time between the South Wales Main Line and the Great Western Main Line could be significantly shortened by the construction of a tunnel directly underneath the

River Severn The River Severn (, ), at long, is the longest river in Great Britain. It is also the river with the most voluminous flow of water by far in all of England and Wales, with an average flow rate of at Apperley, Gloucestershire. It rises in t ...

, which would be faster than the

ferry A ferry is a boat or ship that transports passengers, and occasionally vehicles and cargo, across a body of water. A small passenger ferry with multiple stops, like those in Venice, Italy, is sometimes referred to as a water taxi or water bus ...

service between

Portskewett Portskewett ( or ) is a village and Community (Wales), community (parish) in Monmouthshire, south east Wales. It is located four miles south west of Chepstow and one mile east of Caldicot, Monmouthshire, Caldicot, in an archaeologically sensitiv ...

, Monmouthshire and

New Passage New Passage is a hamlet in the civil parish of Pilning and Severn Beach, in the South Gloucestershire, district, in Gloucestershire, England, on the banks of the Severn estuary near the village of Pilning. It takes its name from the ferry serv ...

, Gloucestershire. During the early 1870s, GWR's chief engineer,

Sir John Hawkshaw Sir John Hawkshaw Royal Society of London, FRS FRSE FRSA MICE (9 April 1811 – 2 June 1891), was an English civil engineer. He served as President of the Institution of Civil Engineers 1862-63. His most noteworthy work is the Severn Tunnel. ...

, developed his design for what would become the

and the company obtained an Act of Parliament on 27 June 1872 that authorised the construction of the tunnel. The tunnel's construction was time consuming and disrupted by water infiltration, yet proceeded nonetheless. The completed tunnel was opened to regular goods trains during September 1886; the first passenger train followed on 1 December 1886. The opening of a more direct route to and from

led to trains from Swindon to

Newport Newport most commonly refers to: *Newport, Wales *Newport, Rhode Island, US Newport or New Port may also refer to: Places Asia *Newport City, Metro Manila, a Philippine district in Pasay * Newport (Vietnam), a United States Army and Army of t ...

and beyond being thereafter routed via

Bath Bath may refer to: * Bathing, immersion in a fluid ** Bathtub, a large open container for water, in which a person may wash their body ** Public bathing, a public place where people bathe * Thermae, ancient Roman public bathing facilities Plac ...

Bristol Bristol () is a City status in the United Kingdom, cathedral city, unitary authority area and ceremonial county in South West England, the most populous city in the region. Built around the River Avon, Bristol, River Avon, it is bordered by t ...

and the tunnel. 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 of new track, and tunnels at Alderton and Sodbury. The new line left the Bath line beyond Swindon at what is now

, rejoining the earlier route north of Bristol near

Patchway Patchway is a town and civil parish in South Gloucestershire, England, situated north-north west of central Bristol. The town has become an overflow settlement for Bristol and is contiguous with Bristol's urban area, along with the nearby towns ...

. Not only did this provide a more direct route for traffic to and from South Wales, the gradients were easier for coal trains to negotiate, and it was thought that the line would be a boost to what was, at the time of building, the expanding port of

Fishguard Fishguard (, meaning "Mouth of the River Gwaun") is a coastal town in Pembrokeshire, Wales, with a population of 3,400 (rounded to the nearest 100) as of the 2021 United Kingdom census, 2021 census. Modern Fishguard consists of two parts, Lowe ...

. This was the GWR's connection with trans-Atlantic

ocean liner An ocean liner is a type of passenger ship primarily used for transportation across seas or oceans. Ocean liners may also carry cargo or mail, and may sometimes be used for other purposes (such as for pleasure cruises or as hospital ships). The ...

departures. During the

era, the line was incorporated into the

and

s were replaced by

s. Perhaps the most significant change occurred in 1976 in the form of the

, a new high speed train fleet that regularly ran at speeds of up to that was first introduced in the

. The Intercity 125 would remain in use into the twenty-first century and marked a considerable improvement in service. In 2005, the

Strategic Rail Authority The Strategic Rail Authority (SRA) was a non-departmental public body in the United Kingdom set up under the Transport Act 2000 to provide strategic direction for the railway industry. Its motto was 'Britain's railway, properly delivered'. It ...

produced a Route Utilisation Strategy for the Great Western Main Line in 2005 to propose ways of meeting increased traffic levels.

Network Rail Network Rail Limited is the owner (via its subsidiary Network Rail Infrastructure Limited, which was known as Railtrack plc before 2002) and railway infrastructure manager, infrastructure manager of most of the railway network in Great Britain. ...

's 2007 Business Plan included the provision of extra platform capacity at ,

and , together with resignalling and line speed improvements in South Wales, most of which would be delivered in 2010–2014.

Electrification

The South Wales Main Line was one of the last of the major inter-city routes in Great Britain to remain un-electrified. In 2012, the British government announced it would proceed with work to electrify the South Wales Main Line as part of a wider scheme of electrification on the Great Western Main Line. The line from London to Cardiff was fully electrified by Christmas 2019, the first electric trains began operating through the Severn Tunnel in June 2020. The Hitachi Super Express trains bought for Great Western inter-city services are predominantly electric units, but a portion of the fleet are dual power source

electro-diesel An electro-diesel locomotive (also referred to as a dual-mode or bi-mode locomotive) is a type of locomotive that can be powered either from an electricity supply (like an electric locomotive) or by using the onboard diesel engine (like a Diese ...

bi-mode trains, which enabled services to operate before line electrification is complete. The bi-mode trains will allow inter-city services to continue to operate from London all the way to

Carmarthen Carmarthen (, ; , 'Merlin's fort' or possibly 'Sea-town fort') is the county town of Carmarthenshire and a community (Wales), community in Wales, lying on the River Towy north of its estuary in Carmarthen Bay. At the 2021 United Kingdom cen ...

in the future. The Super Express trains were expected to bring an estimated 15% increase in capacity during the morning peak hours. Electrification cut journey times between Swansea and London by an estimated 20 minutes, although electrification will not extend west of Cardiff to Swansea, Carmarthen or Pembroke Dock, and services on the line to Brighton, Portsmouth Harbour and Taunton will continue to be operated by diesel trains, as the Bristol to Exeter Line and the

Wessex Main Line The Wessex Main Line is the railway line from Bristol Temple Meads to Southampton Central. Diverging from this route is the Heart of Wessex Line from Westbury to Weymouth. The Wessex Main Line intersects the Reading to Taunton Line at and ...

will not be electrified.

Infrastructure

There are four tracks from

through Newport to Cardiff Central, with two tracks on the remaining sections. Multiple-aspect signals are controlled from several power

signal box A signal is both the process and the result of transmission of data over some media accomplished by embedding some variation. Signals are important in multiple subject fields including signal processing, information theory and biology. In ...

es including Swindon, Bristol and two in Cardiff. Over the August Bank Holiday weekend 2016, control of the signals between Westerleigh Junction and Pilning was switched over to the Thames Valley Signalling Centre. These signals now carry the prefix 'BL'. The maximum line speed from Wootton Bassett Junction to Coalpit Heath is ; from Coalpit Heath to Newport; from Newport to east of Bridgend; from east of Bridgend to Swansea Loop North junction (with a small section of track through Pyle station); and from Swansea Loop North Junction to Swansea.

Associated routes

A diversionary route exists if the

is closed. This takes trains from Severn Tunnel Junction to Gloucester, from where they can rejoin the main line either via the

Golden Valley Line The Golden Valley line is the popular name for the railway line connecting , , and in England. Originally constructed as the Cheltenham and Great Western Union Railway, the line opened between Swindon and Kemble (with a branch to Cirencest ...

to Swindon, or take the

Cross-Country Route The Cross Country Route is a long-distance railway route in England, which runs from to via , , and or . Inter-city services on the route, which include some of the longest passenger journeys in the UK such as to , are operated by CrossCo ...

and reverse at Bristol Parkway. If the line is closed between and , an alternative route exists along the

Vale of Glamorgan Line The Vale of Glamorgan Line () is a commuter railway line in Wales, running through the Vale of Glamorgan from Barry to Bridgend, via Rhoose and Llantwit Major. Route The Barry branch starts at Cardiff West and runs to Barry Island with a ...

. Half of peak High Speed Trains and most off peak trains continue from Cardiff Central to Swansea, with a few continuing to or in summer, . The local service between Swansea and Cardiff is branded

Swanline Swanline is the name of the local rail service from to , on the South Wales Main Line. History The Swanline service was launched in June 1994, following the construction of five new stations at , , , and on the existing South Wales Main ...

. The urban network within and surrounding Cardiff is referred to as the

Valley Lines Valleys & Cardiff Local Routes (formerly Valley Lines) is the urban and suburban rail network radiating from Cardiff, Wales. It includes lines within the city itself, the Vale of Glamorgan and the South Wales Valleys. The services are curre ...

Communities served

;Towns and cities served by trains from London: *

Bridgend Bridgend (; or just , meaning "the end of the bridge on the Ogmore") is a town in the Bridgend County Borough of Wales, west of Cardiff and east of Swansea. The town is named after the Old Bridge, Bridgend, medieval bridge over the River Og ...

Port Talbot Port Talbot (, ) is a town and community (Wales), community in the county borough of Neath Port Talbot, Wales, situated on the east side of Swansea Bay, approximately from Swansea. The Port Talbot Steelworks covers a large area of land which d ...

Neath Neath (; ) is a market town and Community (Wales), community situated in the Neath Port Talbot, Neath Port Talbot County Borough, Wales. The town had a population of 50,658 in 2011. The community of the parish of Neath had a population of 19,2 ...

Swansea Swansea ( ; ) is a coastal City status in the United Kingdom, city and the List of urban areas in the United Kingdom, second-largest city of Wales. It forms a Principal areas of Wales, principal area, officially known as the City and County of ...

;Settlements served by local trains only: *

Pilning Pilning is a village in South Gloucestershire, England, close to Redwick and Severn Beach. Pilning is close to the M4, M49 and A403 roads, and has the South Wales Main Line railway running through it, with a minor station. The civil parish ...

( very limited service) *

Rogiet Rogiet (; ) is a small village and community (and electoral ward) in Monmouthshire, south east Wales, between Caldicot and Magor, west of Chepstow and east of Newport, which covers an area of . It lies close to the M4 and M48 motorways, an ...

Llanharan Llanharan () is a village and community in the county borough of Rhondda Cynon Taf, Wales. As a community Llanharan takes in the neighbouring settlements of Bryncae, Brynna, Llanilid, Peterston-super-Montem and Ynysmaerdy. Llanharan thrived ...

Pontyclun Pontyclun (or Pont-y-clun) is a town and Community (Wales), community located in the county borough of Rhondda Cynon Taf, Wales. Pontyclun translates from the Welsh language as 'bridge

ver Ver or VER may refer to: * Voluntary Export Restraints, in international trade * VER, the IATA airport code for Veracruz International Airport * Volk's Electric Railway, Brighton, England * VerPublishing, of the German group VDM Publishing, re ...

the Afon Clun, River Clun', the Clun being a tributa ...

Pencoed Pencoed (also Pen-coed); ) is a town and community in the county borough of Bridgend, Wales. It straddles the M4 motorway north east of Bridgend and is situated on the Ewenny River. At the 2011 census it had a population of around 9,166. Etymo ...

Pyle Pyle () is a village and community (and electoral ward) in Bridgend county borough, Wales. This large village is served by the A48 road, and lies less than one mile from Junction 37 of the M4 motorway, and is therefore only a half-hour journ ...

* Baglan *

Briton Ferry Briton Ferry () is a town and Community (Wales), community in the county borough of Neath Port Talbot, Wales. The Welsh name may indicate that the church, ''llan'', is protected from the wind, ''awel''. Alternatively, ''Sawel'' may be a deri ...

Skewen Skewen () is a village within the county borough of Neath Port Talbot, in Wales. The village is served by Skewen railway station and has its own Skewen RFC, rugby club. History Skewen was once an industrial village. There were a number of Coal ...

Llansamlet Llansamlet is a suburban district and Community (Wales), community of Swansea, Wales, falling into the Llansamlet (electoral ward), Llansamlet ward. The area is centred on the A48 road (named Samlet Road and Clase Road in the area) and the M4 mot ...

Accidents and incidents

* On 7 March 2015, ''Battle of Britain''-class locomotive 34067 ''Tangmere'' was hauling a charter train that overran a signal at Wooton Bassett,

Wiltshire Wiltshire (; abbreviated to Wilts) is a ceremonial county in South West England. It borders Gloucestershire to the north, Oxfordshire to the north-east, Berkshire to the east, Hampshire to the south-east, Dorset to the south, and Somerset to ...

. The train's operator,

West Coast Railway Company West Coast Railways (WCR) is a railway spot-hire company and charter train operator based at Carnforth MPD in Lancashire. Using buildings and other facilities previously owned by the Carnforth MPD#Steamtown Carnforth, Steamtown Carnforth visito ...

was temporarily banned from running trains on the British railway network as a direct consequence of this incident.

References

Citations

Bibliography

* *

External links

2007 Business Plan
Network Rail, London {{Transport in Bristol Rail transport in Bridgend County Borough Rail transport in Bristol Rail transport in Cardiff Rail transport in Neath Port Talbot Rail transport in Newport, Wales Rail transport in Rhondda Cynon Taf Rail transport in Swansea Rail transport in Wiltshire Railway lines opened in 1903 Railway lines in South West England Railway lines in Wales Standard gauge railways in England Standard gauge railways in Wales