Tag: Taf Fechan River

The Brecon and Merthyr Railway

By the second half of the 19th century, Merthyr was served by several railway companies, one of which was the Brecon and Merthyr Tydfil Junction Railway (B&M) which, as its name implies, ran from Brecon to Merthyr.

A 1905 map showing the Railways around Merthyr and Dowlais

As early as 1836, Sir John Josiah Guest, of the Dowlais Ironworks, had written of his proposal to construct a railway linking Dowlais to the valley of the River Usk, and possibly also running into Brecon. The line would have pretty nearly covered the same route as was eventually adopted by the B&M. A similar proposal suggested a line running up the Taf Fawr valley over the Brecon Beacons via Storey Arms and thence to Brecon.

The Brecon and Merthyr Railway Company was established by a Bill of 1859, financially supported by several prominent Brecon citizens, and the complete route from Brecon to Merthyr Tydfil was authorised the following year. The first section to open was a 6.75 miles (10.86 km) section between Brecon and Talybont-on-Usk in 1863, which reused a section of a horse-drawn tram line. The Beacons Tunnel at Torpantau opened in 1868. Officially named the Torpantau Tunnel, at 1313 feet above mean sea level, it is the highest railway tunnel in Britain.

The system eventually came to comprise two sections of lines:

  • The Southern section, effectively the consumed Rumney Railway, which linked Bassaleg (where there were connections with the GWR and the London and North Western Railway) and the ironworks town of Rhymney, near the head of the Rhymney Valley.
  • The Northern section linked Deri Junction by means of running powers over a section of the Rhymney Railway in the Bargoed Rhymney Valley to Pant, Pontsticill and Brecon via a tunnel through the Brecon Beacons. From the tunnel the line descended towards Talybont-on-Usk on a continuous 1-in-38 gradient known as the “Seven-Mile Bank”. For southbound trains this presented the steepest continuous ascent on the British railway network.
Pontsticill Station. Photo courtesy of http://www.alangeorge.co.uk/index.htm

Initially, the only connection to Merthyr Tydfil was by means of a horse-drawn bus from Pant, but by 1868, a connection with Merthyr at Rhydycar Junction had been established by sharing lines with Vale of Neath, London and North Western and Taff Vale railways. This involved the building of nearly seven miles of single line from Pontsticill to Merthyr, with an almost continuous descent of 1 in 45-50, two complete reversals of direction, and the construction of two viaducts to carry the line over the Taf Fechan at Pontsarn, and the Taf Fawr at Cefn Coed.

North of the Pontsarn viaduct, a connection was made with the LNWR’s Merthyr Extension line at Morlais Tunnel Junction from where the latter’s double track entered the 1034 yard Morlais Tunnel and beyond routed along the double line to Dowlais High Street and thence to Tredegar, Brynmawr and Abergavenny. The sections from Merthyr to Pontsticill and Bargoed through to Brecon were laid as single lines with passing loops and usually locomotive watering facilities at principal stations. For those single lines, tokens were issued to drivers from signal boxes at such locations and being essential for safe working over single lines.

A train leaving the Morlais Tunnel. Photo courtesy of http://www.alangeorge.co.uk/index.htm

The line was eventually amalgamated with the Great Western Railway in 1923, and by 1958, the line was running three services each way on weekdays, increasing to four on Saturdays, taking around 2½ hours to run from Brecon to Newport. Although surviving nationalisation, the service had run at a substantial loss for most of its lifetime, and was an obvious candidate for closure. Passenger services were closed from Pontsticill Junction to Merthyr Tydfil in November 1961, with the remainder of services stopping at the end of the 1962. The line was closed completely after the withdrawal of goods services in 1964.

Towards the end of the 1970s, a private company, the Brecon Mountain Railway, began to build a narrow-gauge steam-hauled tourist line on the existing 5.5-mile (8.9 km) trackbed from Pant through Pontsticill to Dol-y-gaer. The initial section of 1.75 miles (2.82 km) from Pant to Pontsticill first opened in June 1980. After more than 30 years of hard work and extra-funding, passenger services finally extended to Torpantau in April 2014, bringing the BMR to a total of approximately 5 miles in length.

For more about the Brecon Mountain Railway, please follow the link below:

https://www.bmr.wales/

Merthyr’s Bridges: Pont-y-Cafnau

The Grade II* listed Pont-y-Cafnau over the River Taff in Cyfarthfa is thought to be the world’s oldest iron tramroad bridge. An influential early prototype and is a unique survivor of its kind, it is also an aqueduct, with a water trough below the deck. Its designer was Watkin George (c.1759-1822), the chief engineer of the nearby Cyfarthfa Ironworks, which it served, and the bridge/aqueduct enabled the movement of limestone on its tram rails and a water supply, both for the ironworks. The limestone came from the Gurnos Quarries, and the water from a leat supplied by the Taf Fechan. The water was used to drive waterwheels to generate power to run machinery for iron smelting.

The structure was designed sometime in 1792 and construction began in January 1793 and the bridge was completed some time before 1796.

The distinctive appearance of the bridge is created by two large cast iron A-frames, which span the river, their raking ends embedded in the coursed rubble abutment walls on either side. The span measures 14.3m. Three transverse iron beams, at the halfway and quarter-points, connect the A-frames and support the deck. George was originally a carpenter and he used carpentry techniques for the ironwork – mortise-and-tenon and dovetail joints can be seen.

The deck consists of rectangular aqueduct trough, 1.9m wide and 610mm high, made of long iron plates. The trough is covered by an iron deck, cast in sections, on which was laid the 1.22m (4ft) gauge tramroad. Wagons ran on straight iron rails carried on iron chairs. Some chairs and sleepers are still in place along the full length and segments of rail survive at the southern end.

The cast iron handrails were supported at the centre and quarter points of the span. Most of the original cast iron railings have now been replaced.

In 1795, a second bridge was cast from the same patterns to carry an extension of the tramroad and aqueduct from the ironworks to the Glamorganshire Canal. This bridge, sadly, no longer exists.

Shortly after Pont-y-Cafnau was completed, the Gwynne Water Aqueduct (completed 1796) was constructed over the top of it. Gwynne Water was 185m long, built entirely of timber and used the cast iron uprights of the bridge for support. it supplied water to the 15m diameter Aeolus waterwheel, also designed by George, which powered an air pump for the blast furnaces. Presumably, the extra bracing that has been added to the bridge dates from this work. Nothing of the second aqueduct remains.

Pont-y-Cafnau is a Scheduled Ancient Monument as well as a Grade II* listed structure. The iron trough no longer carries water. However, its name means “bridge of troughs”, testifying to its former life.

The bridge influenced the construction of other, better known, aqueducts. In 1794, Shropshire ironmaster William Reynolds (1758-1803) made a sketch of it. Reynolds’ involvement in the rebuilding of Thomas Telford’s (1757-1834) navigable Longdon on Tern Aqueduct on the Shrewsbury Canal in 1796 seems to have led Telford to reconsider using stone and to opt instead for cast iron. It was also the prototype for Telford’s famous Pontcysyllte Aqueduct, which opened in 1805.

Pont-y-Cafnau in March 2017