Powys Metal Mines Survey
(also known as St Harmon)
lies in the community of St Harmon in the county of Powys. It is located at Ordnance Survey national grid reference SN97657930.
The mine is recorded in the CPAT Historic Environment Record as number 8436 and this number should be quoted in all correspondence.
Lead (Pre 1869-1878)
The vein trends ENE in Silurian Frongoch formation rocks. The mineralisation includes galena, pyrite and chalcopyrite.
A large engine shaft, now blocked, and an older shaft, also blocked, are situated at the south-western end of the sett. There was also a deep adit and level both now run-in.
There is a short run of tramway surviving as earthworks on the dressing floors which supply ore to the ore bins above the buddles.
A leat leads off from the stream down to the dressing floors where it supplied water to the buddles and crusher.
Substantial remains of an engine house survive on the dressing floors. This was a 33" cylinder double acting engine used for pumping, winding and crushing. The engine house has brick quoins on the corners and a round chimney attatched to the corner of the
boiler room. There appears to have been a stone lined culvert running northwards out from the engine (?) room. The engine also pumped the West Fedw mine shaft.
A substantial concrete base south-west of the latter building for another horizontal winding engine displays a number of fixing bolts and narrow linear pits. Interpretation is made difficult by the dense tree cover.
A number of small waterwheels are mentioned as being present but the only wheelpit seen was for driving the two buddles.
A large reservoir is located at the south-western extreme of the mine for supplying water to the dressing floors.
There is a bob pit at the rim of the engine shaft.
A crusher house and two round buddles are visible together with a set of seven ore bins above the buddles.
A substantial foundation exists above the buddles which has traces of internal partitions but its function is not clear; it would be the most logical position for a platform for the jiggers.
Two large ore bins, which have largely collapsed due to damage when a nearby farm track was cut through, can be seen below the engine shaft.
Mine office and store buildings are to be found alongside the track into the small forestry plantation below Plas Tylwch.
This HTML page is reproduced from the Powys and Clwyd Metal Mine Surveys which were undertaken between May 1992 and December 1993 by Mark Walters and Pat Frost of the Clwyd Powys Archaeological Trust with financial support from Powys County Council, Clwyd County Council and Cadw: Welsh Historic Monuments. Further information about this site is available in CPAT's Regional Historic Environment Record.
Page produced by Rachel Stebbings and Chris Martin.