MineArchiveTan-yr-Allt Slate Quarry
| Also known as | Tanrallt Quarry, Tanyrallt Quarry |
|---|---|
| Location | Less than 1 km south of Talysarn, Dyffryn Nantlle, Gwynedd — 53.0465, -4.2529 (exact) |
| Commodity | Slate |
| Type | Slate |
| Worked | 1805–1980s |
| Maximum depth | Unknown. |
Overview
An open-pit slate quarry less than a kilometre south of Talysarn, opened in 1805 and worked intermittently, at times with neighbouring Twll Coed, until very small-scale working ended in the 1980s.
History
Tan-yr-Allt (Tanrallt) quarry lies on enclosed land less than a kilometre south of Talysarn in the Nantlle valley. It opened in 1805 as an open pit. Rock was hauled up out of the pit to the north, a mill was later built on the waste across the public road, and the quarry is said to have had up to three water wheels, one perhaps for pumping. It was linked to the Caernarvonshire slate quarries railway by way of Fron Heulog, and for a time it was worked together with the small Twll Coed quarry nearby.
Work came and went. It had a manager of its own in 1877, and the 1,000 tons raised by 40 men in 1873 may have been an exceptional peak. By August 1887 the quarry had stood idle for years, and there was hope in the valley that it would be reopened to employ some of the many men out of work. In 1889 a Talysarn youth was fined for letting two wagons run down its incline. In November 1913 it was stopped by the weakness of the slate trade, putting about 60 men out of work, some of whom went to South Wales for work. Very small-scale working went on into the 1980s.
Geology
Unknown.
Workings
One open pit with an uphaulage incline to the north, worked for a time with Twll Coed quarry.
Closure
Worked intermittently; stopped in 1913 by the slate slump, with very small-scale working continuing into the 1980s.
What remains
The pit is flooded; sheds from the later working, the uphaulage incline and traces of earlier buildings remained in 1991.
The flooded pit, the uphaulage incline formation, a wheelpit, possible barracks, sheds from later working and the abutments of the bridge over the road.
Redevelopment
Unknown.
Nearby mines
- Plassddu Quarry — 0.1 miles (0.1 km) S
- Tymawr West Quarry — 0.4 miles (0.6 km) E
- Cloddfacoed Quarry — 0.5 miles (0.9 km) N
- Tal-y-sarn Quarry — 0.7 miles (1.2 km) N
- Blaenycae Quarry — 0.9 miles (1.5 km) NE
Straight-line distance, within 9 miles (15 km). Show on the map.
Recorded claims
Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.
- Tan-yr-Allt opened in 1805 as an open pit working. 1
- In 1873 the quarry raised 1,000 tons with 40 men, perhaps an exceptional peak. 1
- By August 1887 Tanrallt quarry had stood idle for years. 2
- In 1889 a youth was fined for letting two wagons down the incline at Tanrallt Quarry. 3
- In November 1913 Tanrallt quarry was stopped by the weakness of the slate trade, with about 60 men employed there. 4
- Very small-scale working went on at the quarry until the 1980s. 1
Sources
- (secondary) Tan-yr-Allt Slate Quarry, Talysarn (NPRN 400631) — Coflein (RCAHMW)
- (primary) Y Genedl Gymreig, 17 August 1887: Dyffryn Nantlle — Y Genedl Gymreig (Welsh Newspapers Online, National Library of Wales)
- (primary) The North Wales Express, 21 June 1889: Carnarvon County Magistrates' Court — The North Wales Express (Welsh Newspapers Online, National Library of Wales)
- (primary) Y Llan, 14 November 1913: Llanllyfni — Y Llan (Welsh Newspapers Online, National Library of Wales)
Record created: 20 October 2026 · Last researched: 20 October 2026