Slate Mill, Llanllyfni, Gwynedd

Coordinates

Latitude: 53.0599 / 53°3'35"N

Longitude: -4.2268 / 4°13'36"W

OS Eastings: 250867

OS Northings: 353725

OS Grid: SH508537

Mapcode National: GBR 5K.CCQ7

Mapcode Global: WH54Z.1CH1

Plus Code: 9C5Q3Q5F+X7

Entry Name: Slate Mill

Listing Date: 21 July 2000

Last Amended: 21 July 2000

Grade: II

Source: Cadw

Source ID: 23735

Building Class: Industrial

ID on this website: 300023735

Location: Directly adjoining the slab mill to the south on Level IV (Bonc Isa') of Pen-yr-Orsedd Slate Quarry.

County: Gwynedd

Town: Caernarfon

Community: Llanllyfni

Locality: Pen-yr-Orsedd

Traditional County: Caernarfonshire

Tagged with: Mill Industrial building Industrial building

Find accommodation in
Nantlle

History

Built adjoining the older slab mill in the late 1870s to house 27 De Winton hydraulic feed-saw tables and 26 dressers. At first it was powered by a wire rope transmission from the water-wheel and steam engine power sources in the Level VI mills but after 1906 electric motors were installed in its roof trusses. The slates were removed from the building's roofs c1997. The quarry opened c1816 when it was worked by William Turner. In 1863 it was bought by W A Darbishire & Co., after which it underwent substantial modernisation, reflected in the use of both water and steam power. During the 1890s about 450 men worked here; it finally closed in 1997.

Exterior

Vast rectangular plan slate-slab structure aligned roughly north-west to south-east comprising parallel gable-ended ranges with central valley; the roofs have been entirely stripped of their slates. Doorway roughly in centre of south-west long wall with red brick dressings, raking buttresses and concrete lintel; further entrance in far north-east corner.

Interior

King-post roof trusses throughout, the central roof valley supported on a combination of timber posts and slate-slab piers, the former predominating. The line shafting for the former De Winton hydraulic feed-saw tables survives.

Reasons for Listing

Included as a well-preserved integrated slate mill (notwithstanding loss of its roof covering), significant in illustrating an important advance in technology and the intensive factory approach to slate processing adopted at Pen-yr-Orsedd; part of the remarkably well-preserved complex of buildings on the site.

External Links

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

Other nearby listed buildings

II Slab Mill
Directly adjoins the large slate mill on Level IV (Bonc Isa') of Pen-yr-Orsedd Slate Quarry.
II Ropeway Winding House (north-east)
Located immediately to the north-west of the slate mill on Level IV (Bonc Isa') of Pen-yr-Orsedd Slate Quarry.
II Winding Drumhouse
Located to the south-east of the slate mill on Level IV of Pen-yr-Orsedd Slate Quarry above the remains of the incline leading down to the start of the former Nantlle Railway below.
II Winding Drumhouse and Incline
Located to the south-east of the slate mill on Level VI (Bonc yr Offis) of Pen-yr-Orsedd Slate Quarry, the drumhouse is dramatically sited at the head of the incline running downhill to the south-east
II Locomotive Shed
Directly adjoins the drumhouse on Level IV (Bonc Isa') of Pen-yr-Orsedd Slate Quarry.
II Barracks Building
Located to the south-west of the quarry offices on Level VI (Bonc yr Offis) of Pen-yr-Orsedd Slate Quarry.
II Quarry Offices
Located between the store building to the north and the barracks to the south-west on Level VI (Bonc yr Offis) of Pen-yr-Orsedd Slate Quarry.
II Quarry Hospital
Located to the south-east of the quarry offices on Level VI (Bonc yr Offis) of Pen-yr-Orsedd Slate Quarry.

British Listed Buildings

History in Structure

Slate Mill

A Grade II Listed Building in Llanllyfni, Gwynedd