Drawbridge to carry a junction line between Claypon's Tramroad 1830s extension of the Brecon Forest Tramroad (nprn 406399) to the Palleg Wharf on the Swansea Canal (nprn 34376) and junctions with the Palleg and Ystalyfera Ironworks Railways. It crossed the canal at Lock 25 and its site is now below the valley road built in the 1970s.
Stephen Hughes, RCAHMW, 16.08.2006.