History

Penrhyn Quarry makes up the largest slate workings in the world, and has remained in continuous production since long before the capitalisation of the workings by the first Lord Penrhyn in the late C18. An iron railway connected the quarry to the sea at Porth Penrhyn by 1801 and a mill for the production of slate slabs at Coed-y-parc to the north of the quarry was open by 1803. The quarry was worked partly as a stepped gallery and partly as a pit, which required uphaulage equipment, although from c1850 it began to employ water-balance shafts to raise loaded wagons, a type of technology already common in coal mines. Production of roofing slates remained entirely unmechanised in gwaliau until the introduction of electricity in 1912 led to the building of a range of mills on 'Red Lion', the main quarry level, and the installation of blondin ropeways in the upper quarry. In 1964 the site was bought by McAlpine's which has led to extensive modernisation. The quarry office was built c1860 during a period of expansion at the quarry and in recent years has been considerably extended.

Exterior

Single-storey building in a simpler version of the free Italianate style used for the Penrhyn Estate office at Porth Penrhyn. Regularly coursed and dressed rubblestone blocks with finely jointed voussoirs to door and window surrounds; mainly hipped slate roof. Main elevation has projecting stepped gable to left with round-arched recess framing tripartite sash window with glazing bars and 4-paned sash window above; entrance to right return through segmental-headed 4-panel door. Main section to right has 2 segmental-headed sash windows with similar 2-paned sash window to right again in front wall of small hip-roofed square projection. 2 similar 6-paned sashes in segmental-headed surrounds to right return of main section and 3 sash windows to back wall, all to left of lean-to porch in angle with rear projection giving access to large C20 extension linked to original building. Slate slab ridge stack to far right of main range and similar stacks towards top of its hipped ends.

Interior

Interior retains slate fireplaces with bracketed surrounds.

Reasons for Listing

Included, notwithstanding considerable late C20 extension, as the Victorian quarry office of this nationally important slate quarry; group value with adjoining 'Sebastopol' water-balance shaft.

External Links

• Cadwr Listing
• Wikidata Q29500532

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

• 
  Kent: West and the Weald: The Buildings of England (Pevsner Architectural Guides: Buildings of England)
• 
  Listed Buildings: The Law and Practice of Historic Buildings, Ancient Monuments and Conservation Areas
• 
  Bedfordshire, Huntingdonshire, and Peterborough (Pevsner Architectural Guides): Written by Charles O'Brien, 2014 Edition, Publisher: Yale University Press [Hardcover]
• 
  Specifications for Building Conservation: Volume 1: External Structure: Practical Examples v. 2
• 
  London 3: North West: North West v. 3 (Pevsner Architectural Guides: Buildings of England)
• 
  Dorset (Pevsner Architectural Guides: Buildings of England)