The north Cornwall village of Delabole grew up around the famous slate quarry. Delabole slate has been mined in the area since the Medieval Times and has probably been in existence for some 1000 years. Whilst little is known of the early period, much evidence shows it has been commercially operated for the last six centuries. Today a village has grown up around the industry. The quarry itself is about half a mile long and a quarter of a mile across. The quarry is around 400 feet deep.
During the reign of Elizabeth I, five quarries existed in the area of the present pit and sent slate 'throughout the realm, and even exporting it by sea to Brittany and the Netherlands'.
1602 Carew in his survey of Cornwall wrote 'in substance thin, in colour fair, in lasting long and generally carrieth good regard'.
1784 John Wesley sent Adam Clarke to Delabole Quarry to preach and the spot was named after him as 'Clarke's Hole'. It is still known as this, even today. The first Methodist Chapel was built in 1806, when Robert Blake, the quarry Owner, gave John Wesley land, materials and £40 to build it. The first Bible Christian Chapel was built in 1835, on the site of our Sunday School and the new Chapel was built in 1863.
1841, the five quarries formed themselves into a single controlled unit, and the Old Delabole Slate Company was formed.
1859, in Murrays Handbook of Devon and Cornwall, the author wrote "the quarries present one of the most astonishing and animated scenes imaginable". About 1,000 men were employed at this time, producing 120 tonnes of slate per day. Before the coming of the railway, the slate was cut and hauled six miles to Port Gaverne where it would be loaded onto vessels moored in the harbour area. It would take thirty wagons, pulled by over a hundred horses to load a sixty ton ship and as late as 1890, women still assisted with the stowing of slates.
1898 they became a Limited liability company.
1977 The Old Delabole Slate Company was liquidated by the company's bankers. After this, the quarry moved into corporate hands but this era was short lived
1999 a management buy-out returned the quarry to local ownership. The company then employed 40 people.
2005 The Delabole Slate Company returned to one family ownership. In the 1830's the quarry was owned by the Blake family of Tynes in the parish of St.Teath. Now, after buying out the minority shareholder, the Hamilton family have 100% ownership, and Delabole Slate is a Cornish, family owned business.
In the past slate was quarried by lots of men with digging tools and dynamite. Today they only employ about five people in the actual quarry. They drill down a vertical hole, then they put in two little horizontal holes to join up. Then they pass wire through the holes and cut it out that way. Using the latest diamond wire saws, 600 tonne blocks are sawn from the quarry face, eliminating need for blasting. Wire sawing improves recovery, and prevents the historic building of waste mountains. The five skilled quarrymen, can still average of 120 tonnes of slate block each day.
The quarry is also home to the Delabole butterfly (Spirifer vermuli).
BBC report on Delabole
Delabole Slate Quarry web site
Slate Mines and Quarries in Cornwall