Pont-y-Cafnau Bridge

The Cyfarthfa Ironworks were founded in 1765 and grew to the world's largest ironworks by the early 19th century. In 1771, the works obtained the right to quarry limestone from the Gurnos Quarry for use in the works' blast furnaces, and a gauge tramway was built between 1792 and 1793 to carry the limestone from the quarry into the plant. Pont-y-Cafnau is situated shortly downstream of the confluence of the Taff Fawr and the Taff Fechan to form the Taff. A weir had previously been built upstream of the plant on each river, and leats were built to convey water into the works. The leat from the Taff Fawr was conveyed in a cast-iron elevated aqueduct which ran along the north bank and crossed…

The present bridge was designed by Watkin George. George had been trained as a carpenter, but in 1792 became the chief engineer of the ironworks and a partner in the business. The bridge is composed of two cast iron A-frame trusses supporting a rectangular 2-foot by 6-foot-2-inch cast iron trough. This lower trough carried the Taff Fechan leat and acts as a girder supporting the plates acting as the railway sleepers, into which the rail chairs are integrally cast. Wooden uprights were attached to the iron risers that passed through the apex of each of the A-frames and these supported the upper trough carrying the Taff Fawr leat. Reflecting its designer's roots in carpentry, the members…