Pencader Tunnel
Encyclopedia
Pencader Tunnel is an abandoned railway tunnel
on the old trackbed of the Carmarthen to Aberystwyth main line
in south-west Wales
. It was originally bored for the Llanpumsaint-Pencader section of the Carmarthen & Cardigan
(C&C) Railway.
It is approximately 895 yards (818.4 m) long (just over half-a-mile), making it the longest tunnel in West Wales and is bored through Ordovician
shale
s. It is single-track and built to the C&C's adopted broad gauge
dimensions, as opposed to the smaller standard gauge
used on Britain's railways today. It is also known as alternatively Alltwalis Tunnel and Dolgran Tunnel to local villagers.
and Dolgran, under the Brechfa Forest watershed. Several separate Engineers surveyed the line, including Isambard Kingdom Brunel
, with varying schemes. Brunel proposed a dead-straight tunnel to connect the valleys, though after reworking, the final design was longer in order to ease the gradients.
As built, the tunnel was approximately 895 yards (818.4 m) long, curving slightly from the southern portal in Skanda Vale, running straight for most of its length and then curving for the final third into Dolgran. The digging would require two construction shafts which could then be used for ventilation. Construction started in the spring of 1857 to bore the tunnel at the same time as work began on the first stage of the railway line in the town of Carmarthen.
During construction in 1859, the C&C railway attempted to switch from broad gauge
to standard gauge
, which would have meant all railway infrastructure (including the tunnel), could be built to smaller (and thus cheaper) dimensions. Such a change would require the approval of the British Parliament and pressurisation on the company by the South Wales Railway
, a broad gauge line in the area which did not want the rival standard gauge making an incursion on its territory, meant the application to Parliament never occurred.
Digging initially proceeded from four sites - at either end and from the bottom of the first ventilation shaft sunk. Once the second shaft was finished, digging also commenced from there, though this had been abandoned by May 1860 according to a report which stated that 576 yards (526.7 m) had been dug by this time, approximately two-thirds of the full length. Work was expected to be finished by December 1860/January 1861.
As it stood, the tunnel was only 'finished' in March 1861 although, at the time, it was exposed rock without a brick lining and required further work to complete it. The long approach cuttings were also unfinished at this time. During construction of the tunnel, many of the horses used to haul away excavated rock died from disease and were buried in the field surrounding the northern of the two shafts. The same field also has grassed-over rubble remaining from cottages built by the construction navvies. Much of the spoil excavated was used to build embankments north and south of the tunnel but large spoil heaps can be seen on the hillsides around both ventilation shafts.
Further delays were caused by the original contractor for the railway, Jays of London, abandoning the construction of the line in autumn 1861. By November, however, another contractor, Holdens, had taken over the task. Work was focused on finishing several miles of railway either side of the tunnel and, although easy to the north, to the south, heavy engineering of cuttings and embankments slowed the work.
Track is known to have been laid through the tunnel at some point prior to December 1863, as a company report mentions an accident in that month on a ballast train en-route to Pencader
, beyond the tunnel. Official government inspection was carried out in January 1864 and the tunnel opened with the rest of the Llanpumsaint
-Pencader section of the line on 1 April 1864. At the time, the tunnel was still unlined and a watchman was employed to inspect the tunnel for any rockfalls, until it was eventually lined with brick some years later.
By the time the tunnel was finished, having taken four years to build and a further three to complete the railway approaches to it, the project had crippled the finances of the Carmarthen to Cardigan Railway, which soon went into receivership
. After the railway was closed to freight traffic on 28 September 1973, the track was removed. The tunnel was not demolished and remains in place.
hut. Slightly further south are the foundations of the signal box
for Pencader Tunnel Loop. The tunnel has two air shafts, located on the hillside above it. Both shafts are unlined and varying amounts of ground water drain through them into the tunnel. The north vent shaft was previously used for abseiling until maintenance work fixed a secure grating over it at the same time as the shaft's brickwork was re-pointed.
Walking through the tunnel can be difficult/dangerous due to deep mud at both ends - the majority of the tunnel is dry, however, as it lies on the summit of the line between Llanpumsaint and Pencader and thus any water seeping in drains away naturally. Both portals are muddy, the southern one more so due to a burst culvert over the portal and a small dam of earth that causes water and wet earth to back up behind it into the tunnel.
Further inside, the tunnel is in generally good condition due to being abandoned more recently than many disused tunnels and the brickwork remains in good condition except for a portion near the north portal were some has been dislodged.
There is a persistent local rumour that there is an escape-shaft from the tunnel in the form of a staircase cut into a side-shaft leading to the surface. Though such a shaft does not appear on surveys of the tunnel held by the British Railways Board
, whose remnant, Rail Property Ltd is the current owner of the tunnel and responsible for its upkeep, recent explorations have confirmed its existence. It is unknown how far the passage continues and whether it exits into the ground above.
However, there's hope that one day "once the tunnel is stream free and officially accessable", the Gwili Steam Railway could someday extend into Pencader, once a further a mile or two is required.
Tunnel
A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...
on the old trackbed of the Carmarthen to Aberystwyth main line
Carmarthen to Aberystwyth Line
The Carmarthen to Aberystwyth Line was a 4 ft 8½-in standard-gauge branch line of the Great Western Railway in Wales, connecting Carmarthen and Aberystwyth....
in south-west Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
. It was originally bored for the Llanpumsaint-Pencader section of the Carmarthen & Cardigan
Carmarthen and Cardigan Railway
The Carmarthen and Cardigan Railway was a broad gauge railway from Carmarthen, Carmarthenshire, to Newcastle Emlyn, Wales. Part of the route is now used by the Teifi Valley Railway and the Gwili Railway.Despite the name, the line never reached Cardigan...
(C&C) Railway.
It is approximately 895 yards (818.4 m) long (just over half-a-mile), making it the longest tunnel in West Wales and is bored through Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
s. It is single-track and built to the C&C's adopted broad gauge
Broad gauge
Broad-gauge railways use a track gauge greater than the standard gauge of .- List :For list see: List of broad gauges, by gauge and country- History :...
dimensions, as opposed to the smaller standard gauge
Standard gauge
The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...
used on Britain's railways today. It is also known as alternatively Alltwalis Tunnel and Dolgran Tunnel to local villagers.
History
From the first proposals of the Carmarthen and Cardigan railway it was known that an expensive and long tunnel would be needed to take the line between the valleys of Skanda ValeSkanda Vale
Skanda Vale is a Hindu Temple/Monastery in Llanpumsaint community, Carmarthenshire, south-west Wales. The temple is dedicated to Lord Subramanya, who is also known as Skanda, Karttikeya, and Muruga...
and Dolgran, under the Brechfa Forest watershed. Several separate Engineers surveyed the line, including Isambard Kingdom Brunel
Isambard Kingdom Brunel
Isambard Kingdom Brunel, FRS , was a British civil engineer who built bridges and dockyards including the construction of the first major British railway, the Great Western Railway; a series of steamships, including the first propeller-driven transatlantic steamship; and numerous important bridges...
, with varying schemes. Brunel proposed a dead-straight tunnel to connect the valleys, though after reworking, the final design was longer in order to ease the gradients.
As built, the tunnel was approximately 895 yards (818.4 m) long, curving slightly from the southern portal in Skanda Vale, running straight for most of its length and then curving for the final third into Dolgran. The digging would require two construction shafts which could then be used for ventilation. Construction started in the spring of 1857 to bore the tunnel at the same time as work began on the first stage of the railway line in the town of Carmarthen.
During construction in 1859, the C&C railway attempted to switch from broad gauge
Broad gauge
Broad-gauge railways use a track gauge greater than the standard gauge of .- List :For list see: List of broad gauges, by gauge and country- History :...
to standard gauge
Standard gauge
The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...
, which would have meant all railway infrastructure (including the tunnel), could be built to smaller (and thus cheaper) dimensions. Such a change would require the approval of the British Parliament and pressurisation on the company by the South Wales Railway
South Wales Railway
The South Wales Railway was a broad gauge railway that linked the Gloucester and Dean Forest Railway with Neyland in Wales.-History:The need for the railway was created by the need to ship coal from the South Wales Valleys to London, and secondly to complete Brunel's vision of linking London with...
, a broad gauge line in the area which did not want the rival standard gauge making an incursion on its territory, meant the application to Parliament never occurred.
Digging initially proceeded from four sites - at either end and from the bottom of the first ventilation shaft sunk. Once the second shaft was finished, digging also commenced from there, though this had been abandoned by May 1860 according to a report which stated that 576 yards (526.7 m) had been dug by this time, approximately two-thirds of the full length. Work was expected to be finished by December 1860/January 1861.
As it stood, the tunnel was only 'finished' in March 1861 although, at the time, it was exposed rock without a brick lining and required further work to complete it. The long approach cuttings were also unfinished at this time. During construction of the tunnel, many of the horses used to haul away excavated rock died from disease and were buried in the field surrounding the northern of the two shafts. The same field also has grassed-over rubble remaining from cottages built by the construction navvies. Much of the spoil excavated was used to build embankments north and south of the tunnel but large spoil heaps can be seen on the hillsides around both ventilation shafts.
Further delays were caused by the original contractor for the railway, Jays of London, abandoning the construction of the line in autumn 1861. By November, however, another contractor, Holdens, had taken over the task. Work was focused on finishing several miles of railway either side of the tunnel and, although easy to the north, to the south, heavy engineering of cuttings and embankments slowed the work.
Track is known to have been laid through the tunnel at some point prior to December 1863, as a company report mentions an accident in that month on a ballast train en-route to Pencader
Pencader, Carmarthenshire
Pencader is a small village in the Welsh county of Carmarthenshire, and is part of the Community and Parish of Llanfihangel-ar-Arth. It is located around 5 km south-east of Llandysul and 10 km south-west of Llanybydder....
, beyond the tunnel. Official government inspection was carried out in January 1864 and the tunnel opened with the rest of the Llanpumsaint
Llanpumsaint
Llanpumsaint is a village and community in Carmarthenshire, West Wales. In the 2001 UK Census, Llanpumsaint community had a population of 595...
-Pencader section of the line on 1 April 1864. At the time, the tunnel was still unlined and a watchman was employed to inspect the tunnel for any rockfalls, until it was eventually lined with brick some years later.
By the time the tunnel was finished, having taken four years to build and a further three to complete the railway approaches to it, the project had crippled the finances of the Carmarthen to Cardigan Railway, which soon went into receivership
Receivership
In law, receivership is the situation in which an institution or enterprise is being held by a receiver, a person "placed in the custodial responsibility for the property of others, including tangible and intangible assets and rights." The receivership remedy is an equitable remedy that emerged in...
. After the railway was closed to freight traffic on 28 September 1973, the track was removed. The tunnel was not demolished and remains in place.
Present state
The present state of the tunnel is accessible. Despite being bricked up at one point, both portals are now gated and the northern portal (51.9819°N 4.2994°W) and approach are privately owned and difficult to access due to a stream now occupying part of the trackbed. The south portal (51.9759°N 4.3058°W) is more accessible and has a small shed approximately 500 yards away, a former Permanent WayPermanent way
The permanent way is the elements of railway lines: generally the pairs of rails typically laid on the sleepers embedded in ballast, intended to carry the ordinary trains of a railway...
hut. Slightly further south are the foundations of the signal box
Signal box
On a rail transport system, signalling control is the process by which control is exercised over train movements by way of railway signals and block systems to ensure that trains operate safely, over the correct route and to the proper timetable...
for Pencader Tunnel Loop. The tunnel has two air shafts, located on the hillside above it. Both shafts are unlined and varying amounts of ground water drain through them into the tunnel. The north vent shaft was previously used for abseiling until maintenance work fixed a secure grating over it at the same time as the shaft's brickwork was re-pointed.
Walking through the tunnel can be difficult/dangerous due to deep mud at both ends - the majority of the tunnel is dry, however, as it lies on the summit of the line between Llanpumsaint and Pencader and thus any water seeping in drains away naturally. Both portals are muddy, the southern one more so due to a burst culvert over the portal and a small dam of earth that causes water and wet earth to back up behind it into the tunnel.
Further inside, the tunnel is in generally good condition due to being abandoned more recently than many disused tunnels and the brickwork remains in good condition except for a portion near the north portal were some has been dislodged.
There is a persistent local rumour that there is an escape-shaft from the tunnel in the form of a staircase cut into a side-shaft leading to the surface. Though such a shaft does not appear on surveys of the tunnel held by the British Railways Board
British Railways Board
The British Railways Board was a nationalised industry in the United Kingdom that existed from 1962 to 2001. From its foundation until 1997, it was responsible for most railway services in Great Britain, trading under the brand names British Railways and, from 1965, British Rail...
, whose remnant, Rail Property Ltd is the current owner of the tunnel and responsible for its upkeep, recent explorations have confirmed its existence. It is unknown how far the passage continues and whether it exits into the ground above.
However, there's hope that one day "once the tunnel is stream free and officially accessable", the Gwili Steam Railway could someday extend into Pencader, once a further a mile or two is required.