Hafodlas Quarry

Overview

A Nantlle Valley slate quarry chiefly remembered as the site of the first steam pumping engine ever installed in the Welsh slate industry, in 1807 -- an innovation that ended in dramatic failure a decade later when the engine and two whimsies fell into the quarry pit.

History

Water-wheels and windmills were the standard means of pumping water from the Nantlle quarries until 1807, when Hafodlas Quarry became the site of the first steam pump ever used in the history of the North Wales slate industry -- a significant early step in the mechanisation of Welsh slate working, allowing deeper excavation than gravity-fed water power alone could support. The innovation proved short-lived: in 1817, the steam pump and two whimsies fell sixty yards into the quarry, and within a few days the workings were flooded. Beyond these two documented events, no detailed operating history, ownership record or closure date for Hafodlas Quarry specifically has yet been located, despite a genuine search of the standard Nantlle Valley slate-industry literature.

Workings

Drained originally by water-wheel or windmill power, like the other Nantlle quarries, before the short-lived introduction of steam pumping in 1807.

Abandoned workings can be dangerous — unstable ground, uncapped shafts, flooding and bad air are common even where a site looks safe from the surface. This entry describes history and general location only; it is not an access guide.

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• In 1807 Hafodlas Quarry became the site of the first steam pump used in the history of the slate industry in North Wales, installed to keep the quarry free of water in place of the water-wheels and windmills used elsewhere in the Nantlle valley. ^1,2
• In 1817 the steam pump and two whimsies fell sixty yards into the quarry, and within a few days the workings were flooded. ¹

Photographs & further reading

This page doesn't try to reproduce everything — these are the best original sources found for this mine.

Sources

1. (secondary) Historical aspects of the Welsh slate industry — D. Dylan Pritchard, via slateroof.co.uk
2. (secondary) Slate industry in the Nantlle Valley — Wikipedia

Record created: 30 August 2026 · Last researched: 30 August 2026