Water Balance

A method of winding in which a tank of water, filled at the surface and let down the shaft, raises a loaded tram of coal by its own weight — the pit's power supply being a pond rather than an engine.

Historical usage

Gresley's 1883 glossary marks the water-balance machine as South Welsh and, writing when it was already going out of use, calls it 'an antiquated method of raising minerals in a pit-shaft by water power', the principle being a bucket of water filled at the surface which by its descent raised a tram of twenty hundredweight. It belongs to the shallow pits of the eastern valleys before steam winding became general: Lletty Shenkin at Cwmbach was wound this way from 1843, and Middle Duffryn at Aberdare too. The Royal Commission on the Ancient and Historical Monuments of Wales records a surviving example at Cwmbyrgwm Colliery, Abersychan.

How it worked

A tank or bucket hung in the shaft opposite the cage or carriage carrying the trams. Water was run into the tank at the top from a pond built for the purpose; the brake was released, and the weight of the water carried the tank down and brought the loaded tram up. At the bottom the water was let out, usually into a drainage adit that carried it away from the workings, and the empty tank went back up as the next load came down. Where no adit was available the water had to be pumped back, which took much of the advantage away.

Why it was used

It cost almost nothing to run. A colliery on a hillside with a stream above it and an adit below had, in effect, free winding power, and needed no boiler, no engine and no coal burnt at the surface. For shallow pits raising modest tonnages that was enough.

Risks & limitations

The method could only lift what the head of water would lift, from depths a falling tank could reach, at the pace the tank could be filled and emptied — so it set a hard ceiling on a colliery's output. It depended on a reliable water supply and on somewhere for the water to go. Steam winding, which had none of those limits, displaced it during the second half of the nineteenth century, and by the time Gresley wrote it was already something to be described in the past tense.

Regional variation

Strongly associated with the South Wales coalfield, where it is what the word normally means. The same principle drove water-balance inclines and lifts in the North Wales slate quarries — the Royal Commission records them at Penrhyn, Aberllefenni and Maenofferen — where a descending water tank moved slate wagons rather than coal trams.

Related terminology

Adit, Whim, Winding Engine

Mines associated with this term

Included only where MineArchive's own research gives a reasonable evidential basis — not every mine where this might plausibly apply.

• Bwllfa Dare Colliery — Rhondda Cynon Taf (well documented example)
  Named twice in this record, first in the history: “…to a depth of some 200 yards (180 metres), initially worked with water-balance winding and ventilated by a furnace. Production began in 1856, and…”
• Chartershaugh Colliery — County Durham (well documented example)
  Named twice in this record, first in the summary: “…Haugh Colliery — opened by 1680 near Harraton, notable for an early water-balance winding engine installed in 1753 and for a severe 1778 explosion…”
• Kirkby Slate Quarries — Cumbria (well documented example)
  Named in this record’s workings: “…deep, spreading across and under Kirkby Moor. Inclined trackways and water-balance lifts moved slate out of the pit, and the Sandside trackway once…”

Sources

1. (primary) Cwmbyrgwm Colliery: Water Balance (NPRN 85075) — Royal Commission on the Ancient and Historical Monuments of Wales
2. (primary) W. S. Gresley, A Glossary of Terms used in Coal Mining (1883) — W. S. Gresley; digitised by the Internet Archive
3. (secondary) Glossary of South Wales colliery terms — Welsh Coal Mines

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