then crossed the River Usk to reach Glangrwyne, where iron from Ebbw Vale was worked in a forge Skempton describes a tramroad from Llangroiney [Glangrwyne] to Gellifelen, and a second section from Gellifelen to Fossalog, near Nantyglo, while Gladwin and Gladwin describe a route from Llammarch Colliery to Clydach Ironworks. Dadford's bridge over the Usk collapsed in February 1795, when the river was in flood, and the fact that he had not built flood relief culverts into the embankments on either side of the bridge was deemed to have been a contributory factor in its failure. In July 1794, he became the engineer for the Montgomeryshire Canal, which extended the Llanymynech Branch of the Ellesmere Canal from its terminus at Llanymynech to Newtown. It had been authorised in March 1794, and John was to be assisted by his brother Thomas. The route involved crossing the River Vyrnwy, where a five-arched aqueduct was built, each with a span of , and crossing the River Rhiw at Berriew, where two arches spanned the river, and there were two more arches on the land. One of the arches of the Vyrnwy aqueduct collapsed, and there were troubles with the Rhiw aqueduct. He resigned in July 1796 and emigrated to America. On his brother's suggestion, he was replaced by his father. The committee were critical of the Dadfords, but when they called in William Jessop to advise them, he suggested that such issues were merely teething problems, and were quite normal on such a project. Legacy It is not known what Dadford did after emigrating, and he was not mentioned in his father's will in 1809, which probably indicates that he died there before then. Despite the failure of some of his bridges, he was highly regarded, with the Monmouthshire Canal requesting that if anyone was sent down to inspect the works, they would prefer John Dadford to anyone else. See also Canals of the United Kingdom History of the British canal system Bibliography Notes The spelling of Glangrwyne is encountered in different forms including Glangrwyney and Llangrwyne. References English canal engineers Engineers from the West Midlands (county) Year of death unknown Year of birth unknown