A beam engine installed for drainage purposes at Dorothea Slate Quarry (NPRN 40539). The engine was in installed 1904, replaced by electric working in the 1950's, and restored from 1960's. Associated with: Engine house (NPRN 26409).

Statement of Significance 

A Cornish beam pumping engine by Holman’s of Camborne, situated in the relict Dorothea Slate Quarry in Nantlle, still in its original roofed engine house, emblematic of the already old-fashioned but reliable, de-watering technology imported from Cornwall to counteract rapid ingress of water into deep pits that were necessary to exploit the vertical slate vein in the valley floor quarry pits of Nantlle. It illustrates the influence of water-management technology from the acknowledged industry leaders. The Dorothea engine is one of the last such machines to be installed from new anywhere in the world.    

This site is part of the Slate Landscape of Northwest Wales World Heritage Site, Component Part 3: Nantlle Valley Slate Quarry Landscape. Inscribed July 2020.   

Sources:   

Louise Barker & Dr David Gwyn, March 2018. Slate Landscapes of North-West Wales World Heritage Bid Statements of Significance. (Unpublished Report: Project 401b for Gwynedd Archaeological Trust)   

Tirwedd Llechi Gogledd Orllewin Cymru / The Slate Landscape of Northwest Wales. Nomination as a World heritage Site (Nomination Document, January 2020)   

Wales Slate World Heritage Site https://www.llechi.cymru/    

H. Genders Boyd, RCAHMW, January 2022