Lag Bank Quarry

Overview

A small green slate working at Coniston, held in the 1930s by Broughton Moor Green Slate Quarries Ltd. alongside its Cove quarry. It employed a dozen or so through the late 1920s, jumped to sixty-seven in 1935 and was down to forty-five by 1945, most of them at the surface by then.

History

Lag Bank appears in the Lists of Mines from 1927 returning slate, with thirteen employed, seven below ground and six at the surface. The returns continue through 1929 and 1930 at much the same size, and in 1930 the Durham Mining Museum's company record shows Broughton Moor Green Slate Quarries Ltd. holding both Lag Bank and Cove at Coniston, with five below and eight above at Lag Bank. Then the scale changes: sixty-seven employed in 1935, forty-one of them underground, and forty-five in 1945 with only eight below ground and thirty-seven at the surface — a working that had become mostly a dressing and finishing operation by the end of the war. Its owner is the better-documented half of the story. Broughton Moor Quarry, four miles south-west of Coniston, began in a small way in the mid-19th century, closed, and from the 1920s was reopened and developed into the largest slate mine in England, on a north-east to south-west band of light green slate that also takes in Bursting Stone quarry near Coniston. Most of the Coniston quarries familiar to walkers on the path up the Old Man lie on a band of silver-grey slate and are now closed. Nothing has been found on when Lag Bank itself opened or closed, where exactly it stood, or how it was worked.

Geology

Coniston's green slate is a metamorphosed volcanic ash of the Borrowdale Volcanic Group, Ordovician in age, the same rock worked across the central Lake District and traded as Westmorland or Lakeland Green. Broughton Moor, which owned Lag Bank, lies on a north-east to south-west band of light green slate; the silver-grey band runs through most of the quarries on the Old Man of Coniston.

Geological setting: Slate and Regional Metamorphism (well documented example)

Workings

The Lists of Mines split the workforce between underground and surface, and the split moves: seven of thirteen below in 1927, forty-one of sixty-seven in 1935, but only eight of forty-five in 1945. Beyond that the sources read say nothing about how the quarry was worked, and no grid reference for it has been found — the Durham Mining Museum's own entry records none.

Closure

No closure date has been located. The quarry appears in the Lists of Mines for 1927, 1929, 1930, 1935 and 1945, and in no later list read for this pass.

What remains

Nothing of the quarry's present state was established from the sources read for this pass.

Recorded claims

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

• The Lists of Mines record thirteen employed in 1927, eleven in 1929, thirteen in 1930, sixty-seven in 1935 and forty-five in 1945, the underground share falling from seven of thirteen to eight of forty-five. ¹
• The Durham Mining Museum's company record shows Broughton Moor Green Slate Quarries Ltd. holding Lag Bank and Cove, both at Coniston, in 1930. ²

Photographs & further reading

Sources

1. (secondary) Lag Bank (Slate) — Durham Mining Museum
2. (secondary) Broughton Moor Green Slate Quarries Ltd. — Durham Mining Museum

Record created: 11 September 2026 · Last researched: 12 September 2026