500-year history of Eden Valley gypsum mining

Date: Friday 17th August 2018

THERE has been mining and quarrying of gypsum in the Eden Valley for about 500 years, Graham Brooks, a veterinary practitioner interested in industrial archaeology, told Upper Eden History Society.

He added that one of the problems he encountered while researching this industry is that these operations were on a small scale so they did not produce much of an archive. The main area for gypsum in Britain is around Nottingham.

The gypsum in the Eden Valley was formed about 70 million years ago when most of the area was desert, with occasional lakes forming. Salts were left behind by the receding water; they later became gypsum. There were four main beds in the Eden Valley and miners would move from place to place looking for the thickest seams. Sometimes it was to be found on the surface: Acorn Bank and Long Meg are two such sites.

Over the years gypsum has had a lot of uses. The uncalcined variety when “massive” is alabaster; when crushed, it becomes a drying agent and when powdered, as mineral white, it is used in brewing and clarifying. Calcined gypsum becomes plaster or cement which results in the familiar plaster of Paris.

The first documented evidence of gypsum use in the Eden Valley is at Knott Hill and is dated 1695. This outlines the manor of Cumwhinton where it talks about gypsum quarries.

The first real industrial extraction started in 1837 when Joseph Robinson began manufacturing plaster at Denton Mill, Carlisle. He acquired the gypsum from a number of places around the Carlisle area. After Joseph’s death his nephew, John Thomlinson, took over.

When the Settle-Carlisle railway opened in 1875, John was one of the first to build private sidings to the main line, thereby saving about 40 horse and cart trips per day into Carlisle.

At this time Kirkby Thore was producing whitening or “donkey stones” which were used to whiten the edge of steps: 12,000 of these stones were produced every week. In 1890 all the small producers got together to form a cartel with a fixed price so that they did not compete against each other. This was possibly the start of British Gypsum.

The “main players” in the Kirkby Thore area were the McGee brothers who appeared in 1905. To start with, they quarried the area but put the gypsum straight on a train and sent it to Glasgow.

Later they built a manufacturing unit and in 1915 became the first company in Britain to make plaster board. They also made plaster under the “Thistle” brand which is still available today.

In 1923 a new drift mine was started at Acorn Bank which was powered by a rope haulage system run from the second wheel at the water mill which was 700 yards away.

Eventually, the larger firms from Nottingham came into the area and started buying up Eden’s small firms and modernised them. Long Meg was also redeveloped and is now probably the best preserved of all the old workings; it came into its own in the 1920s when chemists discovered that if they took anhydrite they could make sulphuric acid.

When war came in 1939 there was a sudden massive demand for this in the manufacture of explosives.

In the mid-1950s it was decided that a new large factory needed to be constructed at Kirkby Thore. It was designed to produce 60,000 tons of “Thistle” and “Carlite” plaster. Then, plaster board becoming more popular, a plant to produce this was also built, capable of making 1.5 million square metres of product per year. All the gypsum comes into the factory via a covered conveyor belt.

Graham ended his talk by showing some images of modern plaster board manufacture.