Ynisdavid Colliery Explosion, 1856

An explosion of gas in the Big Vein at Ynisdavid Colliery, Cwmavon, on 24 May 1856 killed twelve colliers. Eight were burnt and mutilated and four died of the effects of gas and their injuries; they were found lying within a short distance of one another. The ground was known to be dangerous, safety lamps only were allowed, and two large Struvé ventilators were being erected but were not yet finished.

Cause

An explosion of gas in the Big Vein.

Contributing factors

An inquiry afterwards found a strong possibility that the explosion had been caused by men smoking in the pit, though it could not discount a faulty or unlocked lamp — either of which would mean a naked flame in a seam known to give off gas.

What happened

The explosion came in the Big Vein at about ten o'clock on the morning of Saturday 24 May 1856. Twelve colliers died, the youngest thirteen and the oldest fifty. Several were killed outright by the blast; the rest succumbed to the gas and to their injuries, some of them slowly — John George, a collier's boy of thirteen, died half an hour after the explosion, Henry Griffiths within three hours, Jason Evans after fourteen, and David Thomas within twenty-five. All were found within a small distance of one another, and one man, the account says, 'was found in a sitting position, with his face resting upon his hands, as though he had, finding escape impossible, calmly sat down to die'.

Rescue & recovery

There was no difficulty in finding the dead: they lay close together. Nothing more about the rescue has been established from sources that could be read for this record.

Investigation & inquiry

The explosion appears in the Inspector of Mines' annual report for 1856 as a single line in the table of fatal accidents, entered under the name of the place, Cwmavon, rather than of the pit. An inquiry found a strong possibility that the explosion had been caused by men smoking in the pit, though a faulty or unlocked lamp could not be discounted.

Legal & regulatory aftermath

No proceedings are recorded in the sources consulted; the inquiry's finding was left at a probability rather than a determination.

Changes to practice & legislation

The two Struvé ventilators being erected at the time were finished afterwards; the same make of machine was installed at Eaglesbush near Neath after its own explosion of 1848, and greatly improved the ventilation there.

Memorials & commemoration

No memorial specific to the explosion has been identified.

Recorded claims

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

• Twelve colliers were killed, eight burnt and mutilated and four dying of the effects of gas and their injuries; they were found lying within a short distance of each other. ^1,2
• The explosion happened at about ten o'clock in the morning of a Saturday shift; The Times of 27 May 1856 also gives about ten, reporting ten dead with two more dying subsequently. ^1,2
• An inquiry found a strong possibility that the explosion was caused by men smoking in the pit, though a faulty or unlocked lamp could not be discounted. ²
• The Inspector of Mines' annual report for 1856 records the explosion in one line in its table of fatal accidents, naming the pit as Cwmavon. ¹

Sources

1. (secondary) Ynisdavid Colliery, Cwmavon — Welsh Coal Mines
2. (secondary) Welsh mining fatalities, 1856: Ynysdavid Colliery, Cwmavon, explosion of gas, twelve killed — Welsh Coal Mines

Record created: 4 September 2026 · Last researched: 4 September 2026