The Teifi Valley Railway (TVR) uses the trackbed of part of the Newcastle Emlyn Branch of the GWR.
This, in turn, joined the Carmarthen to Aberystwyth line at Pencader, Carmarthenshire. Although single-track for the majority of its length, it was considered to be the local main line and there is a campaign locally to get this connection re-established, though road schemes and house building - and effectively the Gwili Railway - are obstacles to this being achieved.
Historically, railways first reach West Wales along the south coast. with the South Wales Railway building a broad-gauge line across from Cardiff to reach Carmarthen in 1852 and later extending towards the west coast, reaching Haverfordwest in 1854 and Milford Haven in 1856.
From the original Carmarthen station, to the south of the current (and third) Carmarthen station, in 1859, the Carmarthen & Cardigan Railway built a broad-gauge line with the intention of reaching Cardigan. Initially opened to Carmarthen's second station and then extending to reach Conwil (1860) and Llandyssul in 1864, the company soon found itself in financial difficulties.
Soon the influence of the GWR was being felt and, as was typical, they began to take over the operations of trains on this company's tracks. By 1866 much of the route had become dual-gauge with both broad and standard-gauge trains running up to Pencader (see below). In 1881 the whole line became part of the GWR and thoughts turned to continuing the line towards Cardigan. By 1895 the line, now standard-gauge only, had reached Newcastle Emlyn - but not on the intended route, for by now the GWR had decided not to proceed to Cardigan.
By 1886 the GWR had reached Cardigan using the route of the Whitland & Cardigan Railway from the south. Faced with fairly unsuitable terrain to avoid the new tourist hotspots of the Cenarth and Cilgerran gorges, the GWR decided that there was not enough traffic to justify building beyond Newcastle Emly, so instead of keeping to the north side of the river Teifi, they crossed into Carmarthenshire near Llandyfriog and built a terminal station and goods yard just to the east of Newcastle Emlyn town in 1895. It is on this section of line, between Llandyssul and Newcastle Emlyn, that the TVR now uses.
Another aspect of local railway history should also be mentioned at this point. Part of the reason for much of the route from Carmarthen up to Pencader being dual-gauged, was due to the emergence of the Manchester & Milford Railway (MMR).
This was what today would appear to be a ludicrous idea. The idea of this railway company was to connect the City of Manchester to the deep water harbour of Milford Haven! Had they not considered Liverpool? 1866 saw the opening of the first part of this venture by a junction with the Carmarthen & Cardigan Railway at Pencader *, heading up, via Lampeter and Tregaron, towards Strata Florida in the foothills of the Cambrian mountains. However it had already been realised that a lengthy tunnel would be required in order to get through to the Llangurig area in mid-Wales. This tunnel would have been the longest railway tunnel in the world had it been built at that time! Indeed there are signs in the Llangurig area - leading up to Llanidloes - of earthworks from where the track would have been laid. Ultimately the MMR would have joined the Cambrian Railway somewhere near Llanidloes - but it was not to be. Instead, a decision was taken to divert across from Strata Florida to Aberystwyth and join the Cambrian Railway there instead and use that railway's tracks across the Welsh Hills to Shrewsbury. Aberystwyth was reached in 1867 and the MMR became part of the GWR in 1911.
* For track enthusiasts, the junction at Pencader became an oddity! After the MMR reached Aberystwyth, the line from Carmarthen to Aberystwyth became the 'main line', whilst the truncated route to Newcastle Emlyn became the branch. In nearly every case, a branch line would turn off the main line, but at Pencader the straight route was the branch whilst the main line turned off this and immediately ran parrallel to the branch. The two lines then ran alongside each other for a few hundred yards, with the main line to Aberystwyth gradually climbing up a bank and the branch descending before turning away to drop down the valley to Llandyssul.
Later, in 1911, a branch off the main line to the north of Lampeter, was opened to the coastal town of Aberaeron. This was built by the Lampeter, Aberaeron and New Quay Light Railway and ran as such for the eleven years leading up to the formation of the 'Big Four' in 1922, when this line also became part of the GWR.
Between 1911 and 1951 things remained calm in West Wales, only nationalisation changing the name of the Company, until in 1964 British Railways, under much financial scrutiny, decided that passenger services even on the main line were not justified. Proposed closure of passenger services was put forward for March 1965, but severe flooding to the south of Aberystwyth, led to termination late in 1964 over the main route between Aberystwyth and Strata Florida, with the rest of the route ceasing in 1965. The Aberaeron branch had ceased passenger operations in 1951, whilst those on the Newcastle Emlyn branch followed in 1952. The Cardigan branch ceased passenger workings in 1962 - with freight ceasing the following year. Over most of the main line from Carmarthen up to Felin Fach Dairy on the Aberaeron branch, freight continued to function. Indeed it was strange that the dairy was only opened in 1951, just as passenger services ceased - strange because it was deliberately located where it was because it was adjacent to the railway line's route!
British Railways in the 1960s and 1970s did little to encourage freight and so it was surprising that freight trains ran north from Carmarthen up to Pencader; down the Newcastle Emlyn branch; and then up to Felin Fach dairy for as long as it did. Until eventually the dairy found that it was cheaper to ship their milk out by road lorries, rather than use the railway! With their decision to cease using the railway, all freight services also ceased and all lines north of Carmarthen were closed in 1973.
Nearly all of the railway routes leading west from Carmarthen are still functioning today. Passenger services run from Carmarthen to Whitland - where the line to Tenby and Pembroke diverges - and Clarbeston Road - where the line to Fishguard and Milford Haven diverge. In recent years there has been some resurgence as services on the Fishguard route, which used to be twice a day to connect with ferry sailings at 2am and 2pm have been supplemented by additional services during the day. Indeed the early afternoon service is the closest thing we have to an express train. Normally using Class 158 units, the train runs along the route to Whitland and Carmarthen, then calls at Llanelli before using the Swansea District Line route through Morriston, to reconnect with the main line at Briton Ferry. However after the Llanelli stop, the next stop is Bridgend and then Cardiff. Even Port Talbot doesn't warrant a stop for it!
Also helping things in West Wales is the doubling of the track between Swansea (Cockett tunnel) and Llanelli, through Gowerton. This means trains no longer have to wait for other services to clear the single-line section now. In order to do this, the bridge across the River Loughor had to be replaced to take double-track. A section of the original historic bridge has been left on an elevated plinth to the side of the railway.