"cyfarthfa" - 1 õppematerjal

Bridges presentation

5in (6cm) diameter wrought-iron rods and five vertical iron posts cast integrally with the wrought-iron chord members. In the last 20 years an older bridge has been discovered in South Wales (UK) at Merthyr Tydfil, a major early 19th century iron- producing centre. Pont-y-Cafnau (Bridge of Troughs) is a unique cast-iron combined aqueduct tramroad bridge below the confluence of the Taff and Taff Fechan, built in January-June 1793 by Watkin George, Chief Engineer of the Cyfarthfa Ironworks, to carry an edge railway and water channel. An iron trough-like girder is carried in an A-frame truss of cast iron spanning 47ft (14.2m), held together by mortise-and-tenon and dovetail joints. The next extant iron railway bridge seems to be another recently discovered at Aberdare (1811), followed by Gaunless. The oldest still in service is Hall's Station Bridge, a Howe truss designed in 1846 by Richard Osborne, a London-born