Clwyd Metal Mines Survey

Westminster Bog

Geology
Carboniferous Limestone.

Workings
The Westminster Vein ran east to west through lands owned by the Duke of Westminster. It was worked in the east by the Nant Mine at SJ197757740 and in the east as far as the Llanarmon Mine at SJ21705680). Any 18th century workings along the vein, apart from open workings on the limestone outcrops, have been obliterated by later workings. The Bog Mines worked the vein over several periods during the 19th century, the eastern extensions being the New Shaft, Mary Ann Shaft and Bog East. The Shaft Capping Programme carried out by NKC Partnership, Rossett, in 1978, included the following shafts for Bog Mine; the Bog Issa Shaft now in the quarry buffer zone at SJ20585721, the ladder shaft adjacent to it at SJ20505721, the Bog Old Engine Shaft at SJ20695709, and the surrounding area of which remains levelled off within the vicinity of the old Bog farm (SJ20855705). An excavator remains on site adjacent to the large reservoir at SJ20805710, but work does not appear to have been done in the area for some time (June 1993). The Bog New Engine shaft at is levelled off at SJ20805699, with surrounding clinker evidence. A shaft lies slightly to the east of this at SJ20755699. The area backs on to the quarry owned by Redland Aggregates. The Bog Mary Ann Shaft at SJ20995686 and the Bog East Engine Shaft at SJ21305680 capped by the 1978 Programme lie to the south-east of this main site. The Grosvenor Caving Club have explored much of the underground workings of the Westminster Vein. Access has been gained from several shafts and artefacts have been found underground, which might shed light on the mining technology.

Transport
No evidence.

Power
Engines working the Westminster Vein were Nant, Castell, Bog New Engine, Mary Ann shaft and the Bog East Mine. The engine houses are illustrated on the 1849 section of the Nant workings (CRO AB/40 CRO). The large reservoir at SJ20805710 must have provided water for the adjacent dressing floors.

Processing
The large dressing floor areas to the south of Carreg-y-sais have been the subject of the 1978 Land Reclamation and Shaft Capping Programme carried out by the NKC Partnership. They were located at SJ20605710 and are now lost in the quarry area. The vast areas of washing waste suggest large-scale operations.

Other features
The old farm buildings would have been mine related.