The railway to west Wales was first projected in 1844, and the proposal was for a line to run from the
Great Western Railway near
Gloucester to Fishguard, with a branch from Whitland to Pembroke. The railway was called the South Wales Railway, and although it was in theory independent of the GWR, in practice it was very closely linked. This was shown by the fact that
Isambard Kingdom Brunel was the engineer, and the line was laid to the
broad gauge. Construction began in 1847, but the company ran into financial difficulties. In addition, the
Great Famine of Ireland reduced the prospective revenue from Anglo-Irish traffic. As a result, instead of completing the line to the proposed port at Fishguard, the Haverfordwest branch was extended to
Neyland where the harbour would cost less. The line from Swansea opened as far as Carmarthen on 11 October 1852, Haverfordwest on 2 January 1854, and to its terminus at Neyland on 15 April 1856. At first, the railway was leased to the GWR, but in 1863 the two companies were amalgamated. The original powers for the branch to Pembroke lapsed, and so in 1859 the
Pembroke and Tenby Railway was authorised to build a ,
standard gauge line from Pembroke Dock to Tenby. The line opened from Tenby to Pembroke on 30 July 1863 and to Pembroke Dock on 8 August 1864. The extension from Tenby to the GWR line at Whitland opened on 4 September 1866. There were two adjoining stations at Whitland with no physical connection between the two lines because they operated on
different gauges. The line was engineered by
Sir James Szlumper. It had its own police force until 1897, due to the high-security of the Naval Dockyard at Pembroke Dock, and the munitions transported. The Pembroke & Tenby Company obtained powers in 1866 to extend their standard-gauge line from Whitland to Carmarthen. This would have enabled the Pembroke & Tenby to link up with the standard-gauge network through the
Llanelly Railway, the
Vale of Towy Railway and the
Central Wales line. Through a series of inter-company working agreements, this would have had the effect of giving the
London & North Western Railway unrestricted access to west Wales. Within the Act for the extension to Carmarthen was a Schedule which allowed either party (the Pembroke & Tenby or the Great Western) to request the Great Western for running powers to the Pembroke company. In doing this the cost of adding a rail to
mix the gauge and installing the necessary junctions at Whitland and Carmarthen was £20,000 to be paid to the Great Western within 18 months of the request. The request was made by the Pembroke company and consequently the Great Western
converted the up line to standard gauge leaving the down line purely as broad. This was not what the Pembroke company was wanting but had to live with it. The Great Western maintained a crossing loop at St Clears for the broad gauge and this caused some hindrance to the Pembroke company. The conversion is noted as the first pure broad to standard gauge for the Great Western. The Pembroke & Tenby ran the first goods trains to Carmarthen on 1 June 1868, and passenger services in August 1869. The G.W.R began leasing the line on 1 July 1896 before finally amalgamated it a year later. Plans were advanced to replace the viaduct and restore double track, and this was completed in April 2013. One intermediate station, Gowerton, also lies on this single-track stretch, with just the former Down (westbound) platform in use for trains in either direction. The disused former Up platform (without track) is still in existence. Less than half of all trains passing through Gowerton can be scheduled to make stops owing to pathing limitations. Additionally, this tight pathing compromised route performance which can amplify delays and hence impact connections into and out of the long-distance Intercity services between Swansea, Cardiff and London. This is important since there are many interchange passengers from the Pembroke Dock line (which is mainly served by trains terminating at Swansea) for Cardiff and English destinations. The double tracking work between Cockett and Dyffryn was completed by July 2013 with a revamped Gowerton railway station having the disused platform brought back into use. This resulted in Gowerton railway station having an additional 95 trains stopping there every week. Additional problems are also found on the Single Lead Junction at Swansea Loop East junction (north of station), which causes conflict between trains from west of Swansea and the eastbound mainline High Speed Train services. There are two passenger companies operating;
Transport for Wales Rail and
Great Western Railway. Great Western Railway introduced a new timetable in 2023, significantly increasing the service on the West Wales line. Their change added 65 trains every week on the line, using the
Fishguard Harbour to
Rosslare Europort service which links with the
Iarnród Éireann trains to
Dublin Connolly on the
Dublin–Rosslare railway line. == Route ==