Dinorwic Quarry Records

Scope and Content

Records of Dinorwic Quarries Co. Ltd, 1809-1970, including financial records, 1809-1969; production records, 1844-1969; sales records, 1835-1970; slate shipment records, 1837-1969; wages records, 1832-1969; accident and safety records, 1884-1969; letter books, 1870-1962; correspondence, 1895-1970; records relating to the formation of the Dinorwic Quarries Co., Ltd, 1950-1954; Quarry Club records, 1861-1969; diaries kept by employees of Dinorwic Quarries, 1889-1969; quarry notices, 1888-1969; records relating to Dinorwic Dock, 1884-1905; records of the Dinorwic steamships, 1902-1958; Port Dinorwic Dry Dock records, 1829-1968; records of Messrs Duff, Herbert and Mitchell, Ltd, 1944-1954; Padarn Railway records, 1841-1961; housing records, 1901-1945; records relating to coal supplies, 1898-1958; electric lighting records, 1902-1937; brick and tile plant records, 1955-1964; plans, mostly relating to the quarry, railway, dock and ships, 1870-1969; Dinorwic publications, 1962-1969; periodicals, 1947-1965; photographs, 1889-1964; and miscellaneous papers, 1864-1970.

Administrative / Biographical History

Slate quarrying at Dinorwig, Caernarfonshire, dates back to the 18th century. In 1787, Thomas Assheton-Smith (1752-1828) of the Faenol estate, leased his workings to the Dinorwig Slate Company, a partnership of two solicitors, Ellis and Wright, and Mr Bridges, a merchant. By 1809, only Wright remained, but he was joined by Hugh Jones, a Dolgellau banker, and Assheton-Smith himself. In 1824, the Dinorwig Tramway was opened, and the Padarn Tramway in 1843, allowing greater amounts of slate to be transported to Port Dinorwic on the Menai Strait. Railways to Porth Penrhyn and Y Felinheli, Caernarfonshire, were completed by 1852. The Dinorwic Quarry operated fleets of iron steamers from Port Dinorwic. Messrs Duff, Herbert and Mitchell Ltd managed the steamships and ship repairs. The quarry grew to become one of the two largest slate quarries in the world, employing more than 3,500 workers. During the 20th century, however, the slate industry declined, although Dinorwic remained one of the primary sources of slate in Wales. Dinorwic Quarries Co. Ltd closed in 1969.


Arranged into the following: Financial; Production; Sales; Slate shipments; Wages; Accident and safety records; Letter books; Correspondence files; Correspondence and other papers; Papers of Dinorwic Quarry Company; Quarry Club; Diaries; Quarry notices; Port Dinorwic; Steamships; Port Dinorwic dry dock; Papers of Messrs Duff, Herbert and Mitchell; Padarn Railway; Housing; Coal; Electric lights; Brick and tile plant; Plans; Dinorwic Publications; Periodicals; Photographs; and Additional material.

Access Information

No restrictions


Compiled by Richard Burman for the ANW project. The following sources were used in the compilation of this description: Caernarfon Record Office, Dinorwic Quarry records, catalogue; Slatesite, (http://www.llechicymru.info/index.english.htm) viewed 16 July 2004; Richards, Alun John, Slate Quarrying in Wales (Llanrwst, 1995).

Other Finding Aids

Hard copies of the catalogue are available in Caernarfon Record Office, the National Library of Wales and the National Register of Archives.

Conditions Governing Use

Usual copyright regulations apply.

Appraisal Information

All records deposited at Caernarfon Record Office have been retained.


Accruals are not expected