Cwmorthin fatal accident and mine-status test case

A fatal accident at Cwmorthin — nicknamed 'The Slaughterhouse' after 21 workers died there between 1875 and 1893 — led to a test case that reclassified the site as a mine rather than an exempt quarry under new safety law, and the company was wound up soon after.

What happened

Cwmorthin gained a reputation for exceptionally dangerous conditions, earning the name 'The Slaughterhouse': 21 workers died there between 1875 and 1893, out of a workforce of around 550. Cause of death for individual incidents is not established by the sources consulted here. The operating company had argued the site was a quarry, exempt from the reporting and safety requirements of the Metalliferous Mines Regulation Act 1872. Following a fatal accident in 1875, a test case was brought against the company, and the enterprise was legally determined to be a mine under the Act.

Investigation & inquiry

The 1875 test case found Cwmorthin to be a mine, not an exempt quarry, under the Metalliferous Mines Regulation Act 1872. The company went into liquidation shortly afterwards.

Recorded claims

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

• Cwmorthin was nicknamed 'The Slaughterhouse'; 21 workers died there between 1875 and 1893, out of a workforce of around 550. A fatal 1875 accident led to a test case that found the site to be a mine, not an exempt quarry, under the Metalliferous Mines Regulation Act 1872, and the company was wound up soon after. ¹

Sources

1. (secondary) Cwmorthin quarry — Wikipedia

Record created: 20 August 2026 · Last researched: 20 August 2026