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Pont y Gwaith
River Taff, north-west of Treharris, Merthyr Tydfil, Wales, UK
Pont y Gwaith
associated engineer
Not known
date  1811
UK era  Georgian  |  category  Bridge  |  reference  ST079976
ICE reference number  HEW 800
photo  © Jaggery and licensed for reuse under this Creative Commons Licence
An early 19th century humpbacked bridge over the River Taff, 9.6km south of Merthyr Tydfil, now looking rather romantic. It is the latest in a succession of bridges used for road access to a nearby ironworks constructed in the 16th century (now disused). Pont y Gwaith suffered subsidence damage but has been restored, and is Grade II listed and now part of the Taff Trail pedestrian and cycle route.
In the late 16th century, a small ironworks (ST079979, NPRN 91519) was established on the west side of the River Taff. The location had plentiful supplies of water for power and wood for charcoal, with iron ore readily available from surface deposits or shallow pits.
A timber bridge — called Pont y Gwaith, or Works’ Bridge — was built to the south of the ironworks so that supplies and materials could be transported over the river. The timber bridge was repaired and rebuilt but by the early 19th century a more durable structure was required. Also, the Merthyr Tramroad, where Richard Trevithick (1771-1833) ran the first locomotive on rails in 1804, had been constructed (1800-02) between Penydarren and Abercynon, bringing additional goods traffic to the area. The tramroad had a passing place (ST081976) on the east side of the river near Pont y Gwaith.
The present 4.2m wide masonry bridge dates from 1811, and is founded partly on bedrock and partly on squared masonry abutments. It's single arch spans 16.8m span, with a 4.8m rise and voussoirs some 700mm deep. 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 midspan. However, it does not have the pierced spandrels of the earlier bridge.
In 1979, Pont y Gwaith was restored. Mining subsidence had caused significant distortion resulting in the arch becoming pointed at midspan. 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.
Research: ECPK
"Merthyr Tydfil Thorough Time" by Kathryn Jane Sellwood, Amberley Publishing Limited, 2014
"Mines, Mills and Furnaces" by D. Morgan Rees, National Museum of Wales, 1967
reference sources   CEH Wales

Pont y Gwaith