Powys Metal Mines Survey

Cwmbyr

Geology
Silurian Upper Llandovery formation. Four veins are present, 2 ENE-WSW and 2 WNW-ESE. Mineralisation includes a clay gangue containing lumps of lead ore. Zinc and silver were also present.

Workings
The main adit is located below the dumps to the north. There are two shafts on the site at SN78629472.

Transport
A short length of tramway leads south-west from the shaft and there is an abandoned ore-wagon close to the rails.

Power
The Nant Cwm-Byr stream fed waterwheels for pumping and crushing. There is a leat on the 1000ft contour across Taren Hengwm to the south. A second leat on the 1000ft contour runs across Taren Bwlch Gwyn to the east. A wheelpit exists for pumping through the adit (41ftx6ft) and for the crusher house (27x3ft). A small wheelpit is located by the buddles. A water turbine (presumably driven by a Pelton wheel) operated a cage winding system later in the mine's life. The pump rod can be seen in-situ in the shaft and there is an in-situ angle bob in the adjacent pit.

Processing
A crusher with a central wheelpit measuring 23x3ft is located south of the mine office/barracks/smithy range of buildings. The wheelpit has a room on either side possibly for dual crushers. The western room has a small western extension which may have been a jigger shed. Part of the waterwheel rim can be seen close to the crusher wheelpit. The wooden remains of two compartment jigs are visible to the south of the crusher house. Wooden launders running north-east lead to two round buddles of 4m diameter, each stone lined. A small 4m long wheelpit can be seen north of the buddles containing part of the wheel rim. This may have been used to drive the buddles although the siting is unusual. There are two ore bins adjacent to the shaft.

Other features
A long row of offices and a workshop are located on the eastern side of the mine adjacent to the present forestry track. The whole range measures some 35x5m in length. There is much ironwork on site and waterwheel rims and strakes are present.

Comments
This mine, until recently, had the most complete collection of surface structures in the county but recent damage has been done by forestry planting and the construction of a forestry access track through the dressing floors.