Longwall

A method of working a coal (or other flat-lying) seam in which a long, straight face is advanced or retreated across a panel of ground, with the entire seam extracted along that face and the roof behind it allowed to collapse or be deliberately packed with waste.

Historical usage

Longwall working originated in Shropshire in the late 17th century and spread gradually across British coalfields over the following two centuries, worked entirely by hand with pick and shovel until the 20th century. From the 1950s and 1960s onward it became fully mechanised, with power-driven coal cutters and shearers working the face and self-advancing hydraulic roof supports following behind them, and it remained the dominant method of British deep coal mining through to the end of large-scale deep mining in the 1990s and 2000s.

How it worked

A face, typically tens to a couple of hundred metres long, is worked along its full length: in the 'advancing' variant, work starts near the shaft and proceeds outward toward the panel boundary; in the 'retreating' variant, access roadways are driven out to the boundary first and the face is then worked back toward the shaft. As coal is cut away, temporary roof supports along the face are advanced forward, and the roof over the worked-out area behind — the goaf, or gob — is left to collapse naturally, or is packed with stone or waste to control subsidence and contain the void.

Why it was used

Working the full width of a seam along one continuous face, rather than leaving unworked pillars as in room-and-pillar mining, allowed a far higher proportion of the coal to be recovered and lent itself readily to mechanisation, since cutting machinery and roof supports could advance along a single straight line rather than around a irregular network of pillars and roadways.

Risks & limitations

The goaf left behind a longwall face is where much of the method's real danger lies: if the roof does not collapse and seal as expected, firedamp can accumulate undetected in cavities within the waste, later being released suddenly by further roof movement — the specific mechanism identified in the 1951 Easington Colliery disaster, where gas built up in unfilled roof cavities behind a retreating face. HM Inspector of Mines Joseph Dickenson also attributed part of the blame for the 1866 Oaks Colliery disaster to the longwall method then in use.

Regional variation

Longwall working largely displaced the bord-and-pillar (or room-and-pillar) method that had dominated earlier British coal mining, particularly in the Midlands and parts of Wales; Scotland's older 'stoop and room' working followed a broadly similar pillar-based logic before longwall spread there too.

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.

• Kellingley Colliery — North Yorkshire (well documented example)
  The mine's own recorded workings explicitly describe longwall working.
• Oaks Colliery — South Yorkshire (well documented example)
  The mine's own recorded geology explicitly describes the longwall method used to work the Barnsley Seam.
• Point of Ayr Colliery — Flintshire (well documented example)
  The mine's own recorded workings explicitly describe longwall working.

Disasters associated with this term

Included only where MineArchive's own research gives a reasonable evidential basis, with the nature of the relationship stated — not every disaster where this term might plausibly apply.

• Easington Colliery explosion, 1951 (direct cause)
  The official inquiry found firedamp had accumulated in cavities behind a retreating longwall coalface where the roof failed to collapse and seal as intended.
• Oaks Colliery explosion, 1866 (contributing factor)
  HM Inspector Joseph Dickenson attributed the disaster in part to the longwall mining method used on the Barnsley Seam.

Sources

1. (secondary) Brief History of Longwall Coal Mining in Illinois — Illinois State Geological Survey
2. (secondary) Longwall Mining - History and Methods — Mining Science and Technology

Record created: 23 August 2026 · Last researched: 23 August 2026