Delabole Slate Quarry fall, 1869

On the evening of 21 April 1869 the 250-foot face of the Landwork quarry at Delabole slate quarry, Cornwall, fell into the pit with the poppet head on top of it, killing fifteen or sixteen people, among them a grandfather and his two small grandsons.

Cause

The quarry face came away along its whole height without warning beyond a crack noticed eight minutes before.

What happened

Delabole's slate quarries, near Camelford, formed one great excavation of sixteen acres, 200 to 300 feet deep, and employed about 350 people. In the part called Landwork a cliff face some 250 feet high, slightly undercut, carried at its top the largest poppet head on the works, a staging projecting over the pit with pulleys for drawing stone and rubbish to the surface. Directors had stood on it a few hours earlier. About five o'clock on 21 April 1869 men on the staging noticed a crack a quarter of an inch wide behind it; one, George Wallis, went to tell the foreman, Captain Moore. Within eight minutes, about 5.30, the whole face came away, a mass some 300 feet long and 100 to 150 feet deep, carrying everyone on the poppet head down to the floor of the pit and burying men working below. A man on the face, Crart, heard the rock bursting and shouted in time for his party of twelve to get clear. Because the men had stopped for tea, many who would have been in its path escaped, but a young woman and two children who had brought them refreshment were among the dead.

What's uncertain

Points where sources disagree or the record could not be settled; both accounts are kept. All open questions in the archive.

• Sixteen lives were lost and several people injured. (disputed) ²
• Fifteen people were killed. (disputed) ¹

Recorded claims

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

• About 5.30 p.m. on 21 April 1869 the face of the Landwork quarry at Delabole fell into the pit, carrying with it the poppet head, the largest on the works, and everyone on it, and burying men working beneath. ^1,2
• Sixteen lives were lost and several people injured. (disputed) ²
• Fifteen people were killed. (disputed) ¹
• Men on the poppet head noticed a crack a quarter of an inch wide behind the staging about five o'clock; within eight minutes of its discovery the whole face came away. ²
• The mass that fell was about 300 feet long and 100 to 150 feet deep, well over a hundred thousand tons; among the dead were a young woman and two children who had brought tea to their relatives. ^1,2

Related terminology

Mining terms this disaster is structurally linked to, with the nature of the relationship.

• Captain (contextual relationship)
  Named in this record’s narrative: “…inch wide behind it; one, George Wallis, went to tell the foreman, Captain Moore. Within eight minutes, about 5.30, the whole face came away, a…”
• Slate (contextual relationship)
  Named twice in this record, first in the summary: “…21 April 1869 the 250-foot face of the Landwork quarry at Delabole slate quarry, Cornwall, fell into the pit with the poppet head on top of…”

Photographs & further reading

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

Sources

1. (primary) Disaster: Delabole Slate Quarry, 21 April 1869 — Durham Mining Museum
2. (secondary) Coroner's Inquest: Fatalities at Delabole Slate Quarries, 1869 (Royal Cornwall Gazette, 29 April 1869) — Cornwall Online Parish Clerks

Record created: 5 October 2026 · Last researched: 5 October 2026