History

Llantrisant or Ynysmaerdy Colliery was established by the Powell Duffryn Steam Coal Company after World War I. It closed in 1942 following an underground explosion. It was constructed on the efficient modern model developed by the Powell Duffryn Company, with a single engine hall containing the main power equipment needed on the surface. The site is a particularly complete and impressive colliery complex, containing the engine hall, workshops and stores, ruined offices, a separate winding engine house, railway lines, tips, a long revetment wall, a reservoir, and an explosives store. It was associated with the planned housing estate at Ynysmaerdy.

Exterior

The reservoir is a perfectly circular structure approximately 30m in diameter and 9m high, erected between the rock faces of a former quarry on the line of a small stream. It is constructed as a thin reinforced concrete shell with straight vertical sides topped with a narrow lip, and a dished bottom. The use of concrete in such a structural form was unusual at this date, and this example demonstrates some virtuosity of design.

Reasons for Listing

Listed for its advanced use of reinforced concrete, and for group value in this unusually complete and impressive colliery complex.

External Links

• Cadwr Listing
• Wikidata Q29493551

External links are from the relevant listing authority and, where applicable, Wikidata. Wikidata IDs may be related buildings as well as this specific building. If you want to add or update a link, you will need to do so by editing the Wikidata entry.

Recommended Books

• 
  Berkshire (Pevsner Architectural Guides: Buildings of England)
• 
  Listed Buildings and Other Heritage Assets
• 
  Kent: North East and East (Pevsner Architectural Guides: Buildings of England)
• 
  England's Post-War Listed Buildings
• 
  Yorkshire West Riding: Sheffield and the South (Pevsner Architectural Guides: Buildings of England)
• 
  Hertfordshire (Pevsner Architectural Guides: Buildings of England)