Glenavon Colliery inrush, 1900

Five colliers drowned when a heading being driven towards old, water-filled workings at Glenavon Colliery broke through on 24 October 1900 — the boring ahead of the face had underestimated a fault's throw and so missed the water it was meant to detect.

Cause

A heading was being driven on three shifts towards the old Caerau workings, known to contain water, with boring ahead of the face as required by the Coal Mines Act. A fault between the heading and the old workings was thought to have a throw of 18-20 feet but was in fact only about 7 feet; the fault's presence had created a false sense of security, and even the boreholes drilled were not deep enough to strike the old workings before the face advanced into them.

What happened

Glenavon Colliery, a drift mine at Croeserw in the Afan valley locally known as 'The Squint', had opened in 1899 and was worked by the Glenavon Rhondda Collieries Company, Limited. A heading was being driven towards the old Caerau workings, on the far side of a geological fault, in a seam 6 feet 5 inches thick; one shift bored ahead while the others worked coal and shale. On the evening before the disaster the borers finished at 10pm, having struck the fault with one hole at 13 feet and reached about 18 feet in advance of the face with another; a fresh flank hole had progressed only 4 feet. The following shifts worked the coal and shale, advancing the face by about 3 feet, when at roughly 9.15am on 24 October 1900 water began pouring from the roof near the left-hand corner of the heading. It continued for hours, completely flooding a dip working and the stalls branching from it. The five men working there were drowned; about 80 other men in the colliery escaped via the upcast shaft.

Investigation & inquiry

The Mines Inspector's subsequent examination found the fault's true throw was only about 7 feet, not the 18-20 feet assumed at the time — a discrepancy the Inspector attributed partly to an attempt to prove the fault from the Caerau side by drifting downward, which would have reduced the apparent thickness of intervening strata. The Inspector concluded the fault's presence had created a false feeling of security, and that even a longer flank borehole would probably not have struck the old workings before the face reached them. Cited references: the 1900 Mines Inspector's Report, and the Colliery Guardian of 9 November 1900.

Memorials & commemoration

No memorial has been found for this disaster.

Recorded claims

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

• Thomas Curtis, Rees Jenkins, David Jenkins, David Jones and Evan Jenkins, all colliers, drowned. ^1,2

Related terminology

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

• Coal (contextual relationship)
  Named twice in this record, first in the narrative: “…6 feet 5 inches thick; one shift bored ahead while the others worked coal and shale. On the evening before the disaster the borers finished at…”
• Colliery (contextual relationship)
  Named 4 times in this record, first in the summary: “…heading being driven towards old, water-filled workings at Glenavon Colliery broke through on 24 October 1900 — the boring ahead of the face had…”
• Downcast Shaft and Upcast Shaft (contextual relationship)
  Named in this record’s narrative: “…were drowned; about 80 other men in the colliery escaped via the upcast shaft.”
• Drift (contextual relationship)
  Named in this record’s narrative: “Glenavon Colliery, a drift mine at Croeserw in the Afan valley locally known as 'The Squint',…”
• Stall (contextual relationship)
  Named in this record’s narrative: “…It continued for hours, completely flooding a dip working and the stalls branching from it. The five men working there were drowned; about 80…”

Sources

1. (secondary) Glenavon Colliery (Welsh Coal Mines) — Welsh Coal Mines
2. (secondary) Glenavon Colliery Inrush - Rhondda - 1900 — Northern Mine Research Society

Record created: 13 September 2026 · Last researched: 14 September 2026