Cwmbran Colliery scalding, 1866

At about half past two in the morning of 26 April 1866 a haulier bringing trams along the main horse road at Cwmbran Colliery came past the underground boilers too fast. The trams flew off the plates and knocked down the upright pipe carrying the cock used to blow the boilers through, and live steam poured out so fiercely that none of the three men there escaped. The Inspector had double cocks fitted afterwards.

Cause

Runaway trams knocked down the upright steam pipe and blow-through cock of the underground boilers, releasing live steam.

Contributing factors

The water used to raise steam was so bad that the boilers often had to be blown right through, and the large cock for doing so stood unavoidably close to the main horse road. The haulier's horse either ran away or was driven too fast.

What happened

Cwmbran Colliery in 1866 was John Lawrence's, worked by the Mine Slope he had opened in 1854 and with a steam engine underground for the deep workings. Its boilers stood beside the main horse road, and because the water used to raise steam was so bad the boilers frequently had to be blown right through; the large cock for doing so was, in the Inspector's words, unavoidably close to the road. At about half past two in the morning of 26 April a haulier came out along the road with his trams. Either his horse ran away or he drove it too fast, for on arriving at the boilers the trams flew off the plates and knocked down the upright pipe to which the blow-through cock was attached. The escape of steam was so rapid and fierce that none of the three men there got away: John Morgan, 22, Isaac Maynard, a mason of 39, and Robert Allen, 23. Welsh Coal Mines has Morgan as the stoker and Allen as the haulier; the Durham Mining Museum's register, following the Inspector, has them the other way about. The Inspector afterwards had double cocks fitted so that, as he put it, there was but little possibility of any repetition.

Investigation & inquiry

The Inspector of Mines described the accident in his report, saying he had since had double cocks fitted so that there was little possibility of a repetition.

Changes to practice & legislation

Double cocks were fitted to the underground boilers.

What's uncertain

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

• Welsh Coal Mines gives John Morgan as the stoker and Robert Allen as the haulier; the Durham Mining Museum gives Allen as the stoker and Morgan as the haulier, recording all three deaths as 'boiler explosion'. (disputed) ^1,2

Recorded claims

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

• Three men were scalded to death on 26 April 1866 when runaway trams left the rails and burst a steam pipe feeding a haulage engine: John Morgan, a stoker of twenty-two, Isaac Maynard, a mason of thirty-nine, and Robert Allen, a haulier of twenty-three. ¹
• The Inspector wrote that the water for the underground engine's boilers was so bad they had often to be blown through by a large cock unavoidably close to the main horse road; about 2.30 a.m. the haulier's horse ran away or was driven too fast, the trams flew off the plates at the boilers and knocked down the upright pipe carrying the cock, and none of the three men escaped the steam. Double cocks were fitted afterwards. ¹
• Welsh Coal Mines gives John Morgan as the stoker and Robert Allen as the haulier; the Durham Mining Museum gives Allen as the stoker and Morgan as the haulier, recording all three deaths as 'boiler explosion'. (disputed) ^1,2

Related terminology

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

• Colliery (contextual relationship)
  Named in this record’s summary: “…1866 a haulier bringing trams along the main horse road at Cwmbran Colliery came past the underground boilers too fast. The trams flew off the…”
• HM Chief Inspector of Mines (contextual relationship)
  Named in this record’s investigation: “The Inspector of Mines described the accident in his report, saying he had since had double…”
• Haulier (contributing factor)
  The haulier's horse ran away or was driven too fast.
• Tub (contextual relationship)
  Named 3 times in this record, first in the summary: “…half past two in the morning of 26 April 1866 a haulier bringing trams along the main horse road at Cwmbran Colliery came past the…”

Sources

1. (secondary) Cwmbran Colliery — Welsh Coal Mines
2. (primary) Cwmbran Colliery — Durham Mining Museum

Record created: 10 September 2026 · Last researched: 16 September 2026