Although Merthyr is world famous for its ironworks, most people don’t realise that there was an ironworks established in the Merthyr Valley as early as the late 16th Century. In 1583, Anthony Morley, an ironmaster from Sussex, set up a small ironworks on the western side of the River Taff between Merthyr Vale and Edwardsville.
The location had plentiful supplies of water for power and wood for charcoal, with iron ore readily available from surface deposits or shallow pits, but supplies and materials had to be transported over the river. To accommodate this, a wooden bridge was built and called Pont y Gwaith – literally Works’ Bridge. The small hamlet that built up around the ironworks took its name from the bridge.
The Pont y Gwaith Ironworks eventually closed, but the hamlet flourished, but by the early 19th Century, the Merthyr Tramroad, where Richard Trevithick ran the first locomotive on rails in 1804, had been constructed between Penydarren and Abercynon, bringing additional goods traffic to the area. The tramroad had a passing place on the east side of the river near Pont y Gwaith.
With the increase in traffic, the old wooden bridge wasn’t deemed suitable, so a replacement bridge was built. A new stone bridge was built in 1811 founded partly on bedrock and partly on squared masonry abutments. Its single arch spans 16.8m span, with a 4.8m rise. The slope of the approaches has been designed so that the curve of the parapet walls echoes the steep rise of the arch.
The bridge shares several design features with the longer-span William Edwards Bridge (Pontypridd, completed 1756), including the use of narrow stones to form the arch ring, the steep road gradient and a plan form that narrows from the abutments towards the midspan.
By the 1970’s mining subsidence had caused significant distortion resulting in the arch becoming pointed at midspan, so in 1979 the bridge was restored and a lightweight concrete saddle was used to strengthen the arch.
The bridge was awarded Grade II listed status in June 1988, and later became part of the Taff Trail from Cardiff Bay to Brecon. In 1989, it was closed to vehicles. In 1992-93, the bridge was repaired by Mid Glamorgan County Council and received a commendation from the Civic Trust.
Photos courtesy of Janice Lane.