Mines of the Rheidol Valley: The Erwtomau Mill By Ioan R Lord
N.B. This mine is on Private property and entry is forbidden unless by prior arrangement. Mines in the Valley are very dangerous owing to the vertical shafts and the potential for them to be hidden within woodland. Exploration should only be undertaken by experienced persons!
Reconstruction of the Erwtomau Mill, April 2017.
Erwtomau Mine was a modern rebirth of the ancient mine of Rhiwrugos, which is located in the ravine of Cwm yr Ogof, near the Horseshoe Bend above Rheidol Falls Halt. The opening of the Vale of Rheidol Railway in 1902 led to one of the nine adits of Rhiwrugos Mine, which has perhaps been in existence since prehistoric times, to be reopened under the title of ‘Erwtomau’. The adit chosen was No. 2 Adit, which lay just above the level of the new railway. Operations as Erwtomau Mine commenced in 1909 under the Rheidol Valley Mining Company, and a modern dressing mill was constructed in 1911 between No. 2 Adit and the VoR trackbed. The workings were reopened because of the growing demand for ‘Black Jack’ or zinc ore, which had been left in the mine by the nineteenth-century miners Page 7
who were chiefly raising lead. To dress the Black Jack and form zinc concentrate, the mill housed a hand-picking table, an Acme stonebreaker, rock crusher, four trommels and four jiggers. There was one Wilfley and one locally-made Green’s Ore Table, and one flat buddle. These represent the various stages of reducing the size and sorting the ore that came out of the mine, so that the washing and cleaning processes could be carried out. The machinery in the mill was powered by a suction gas plant, driven by a Fielding & Platt gas engine of 68bhp. It had a 22” × 16½” stroke and cylinder, with a gas generator, wet and dry scrubbers, air cylinder and self-starter. A 3” centrifugal pump was also included to increase the pressure of water being poured onto the ore tables from a wooden channel, which was fed by Nant Rhiwrugos.