Arches at former Ynysgedwen Iron Works

Cadw's description

Location

Situated on grassed site bounded by Glan-Rhyd Road and Pont Aur, just N of Ystradgynlais Hospital.

History

Remaining walls of an uncompleted later C19 iron works, consisting of 2 parallel yellow brick arcades. They were never apparently roofed. The Ynys Cedwen site goes back to at least 1612, the date found on a pig of iron. The use of anthracite coal for smelting iron was discovered here by George Crane and David Thomas in 1836. David Thomas took the technology to the LeHigh valley Pennsylvania in 1839, establishing the Thomas Iron Works, by 1854 the largest producer in the country. At Ynysgedwen there were 3 furnaces by 1837 and 6 by 1853 but the works declined from 1860, closing in 1869-70. The survivng walls were part of an uncompleted rolling-mill begun in 1872 in an attempt to revitalise the site. The iron works closed in 1876. There was a tin-plate works here from 1889-1903 and 1905-41. The site was cleared and landscaped in the late C20, removing all but the arcades and chimney of 1872.

Exterior

Two widely separated parallel yellow-brick arcades each of six large arches on seven rectangular piers. Piers each have 2 flush bands of large terracotta blocks, chamfered plinths, moulded brick bands and capitals to the piers. Moulded brick outer ring to arches of header bricks in 3 rings. Flat coping at wall-plate level, replacing moulded brick, the height about 9-10m. Moulded yellow brick detail included bull-nosed band to columns and arch ring and more complex capitals to the piers. There were iron brackets on insides where the roof-trusses would have been fixed, now cut back to wall-face.

Reason for designation

Included as the impressive remaining part of a very important Welsh industrial site.