The Felin Fawr workshop and slate processing Works was extended eastwards in 1906-7, which meant the diversion of a public road. The 26ft (7.9m) diameter wheel was constructed at this time, to power a machine shop and the blower for the foundry. It was supplied by H Sugden & Son, of Bramley, Leeds, and is set in a deep pit. The suspension wheel has cast iron hubs and shrouds, with a round wrought iron axle and wrought iron spokes and cross-braces, and sheet iron buckets. Power was taken off by a pinion engaging in a cast iron gear ring on the west side of the wheel. Water for the wheel was piped from the two reservoirs on the Afon Galedffrwd to the south-west of the Works.

Information from Cadw Listed Buildings database.
W J Crompton, RCAHMW, 8 November 2018.