Birkhill Caverns Clay Mine

Birkhill Fireclay Mine - Birkhill Clay Mine

Useful Information

Location:	Bo'ness, West Lothian, Scotland. (55.99329695979566, -3.660694172239948)
Open:	Closed. [2021]
Fee:	Closed. [2021]
Classification:	Clay Mine
Light:	Incandescent Electric Light System
Dimension:	T=11 °C, L=10 km, VR=823 m.
Guided tours:	D=60 min.
Photography:
Accessibility:
Bibliography:	Descent 101 Aug/Sept 1991 25. Tourist Brochure 2001
Address:	The Bo’ness & Kinneil Railway, Bo’ness Station, Union St, Bo’ness EH51 9AQ, Tel: 01506 822298. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

18th century	beginning of open cast mining.
19th century	first shaft excavated north of Tod’s Hill.
1906	Bradley & Craven Steam mill installed which provided power for the crusher, pump, and Pulley system.
1908	Birkhill leased from the Hamilton Estate by Mark Hurll, a firebrick manufacturer from Glenboig in Lanarkshire.
1913	second series of workings opened further north.
1916	Birkill acquired by P&M Hurll (established in 1887).
1930s	electricity installed.
1932	mining started.
1951	third and largest shaft was opened.
1980	mining abandoned.
1987	developed as a show mine.
1990s	Heritage Trust closed and responsibility for the mine transferred to Falkirk District Council.
2013	show mine permanently closed.

Geology

Fireclay is composed of quartz SiO₂ and aluminum oxide Al₂O₃, with 5-80% SiO₂ and between 20-45% Al₂O₃. High Alumina Bricks have an aluminum oxide Al₂O₃ content above 45%. Higher alumina content gives better refractoriness at higher temperatures. The bricks are calcined at high temperatures. The high density and a low porosity are the result of a very low amount of bonding clay. Such bricks have an excellent mechanical strength and excellent physical properties for application up to 1,550 °C.

Fireclas is commonly found close to coal mine deposits. At Birkhill a a thick layer of sandstone covered the clay. which gave the underground mine the necessary stability. Three layers of clay were mined, which were named after their colour. The lowest was the Dark Fireclay, which was the tickest, then there was a layer Gray Fireclay and on the top was a thinner layer of Black Fireclay..

Description

The Fireclay Mine was actually a mine for clay, which is really exceptional. Unconsolidated sediments like gravel, sand, and clay are normally mined in open cast mines. The main reason is obvious: they are close to the surface, so it is much cheaper. If they were deeper underground, the gravel would have become breccia, the sand into sandstone and the clay into mudstones. But there is another reason: unconsolidated sediments are not stable, any kind of underground mining would easily collapse. Ever built a sand castle?

For the creation of a clay mine like this there are two requirements, a clay which is special and quite valuable to make the mining profitable and a geologic situation which allows safe mining. High quality high alumina fireclay is important for the production of heat resistant bricks, which are used in ovens, furnaces, chimneys, flue liners, and steam boilers. The fireclay was mined since the 18th century, but underground mining started in the late 19th century. The first shaft was sunk just north of Tod’s Hill. In 1906 a Steam mill was installed which provided power for the crusher, pump, and Pulley system and processed 1 to 2 tons per hour. Birkhill was leased in 1908 from the Hamilton Estate by Mark Hurll, a firebrick manufacturer from Glenboig in Lanarkshire. In 1916 Birkill acquired by P&M Hurll (established in 1887). They opened a second shaft further north in 1913. In the 1930s electricity was installed and an electric mill which could process 10 tons of clay per hour. The third and largest shaft was opened in 1951 on the west side of river Avon. The production reached its peak.

The mining used the room and pillar method, which was here called Stoup and Room. The stoup was a wide pillar of fire-clay, which was left in place to support the roof. Intersecting galleries were called roads, the chambers left between the pillars were called room. Beneath the pillars timber pit props where needed to further support the roof, because the clay was not stable enough.

The clay face advanced 1.2 m per day by manual excavation. The men worked in pairs, using traditional mining technology. First a fireman checked the mine for safety. Then they shoveled the fireclay into hutches and pushed them to the main hutch-line. They put on a tag to identify the load as theirs, because they had a target of about 15 hutches full per day, each team of miners shifted about 10 tons of clay per day. The hutches were collected and hooked on to a haulage system by a bencher. Then the miners drilled holes in rack with a hand borer called rickety. They filled the holes with explosives at the end of their shift blasted down the next meter of clay. Over night the dust settled and the poisonous remains of the explosives were gone and all started over.

The clay was transported with a narrow gauge inclined railway 300 m to thw mill. The railway had 12 fully loaded hutches carrying a total of 12 tons of clay. The raw clay from the mine was passed through a kibbler and then further refined in the pan mill. It was then transported brickworks site at Glenboig or direct to other fire clay users within the UK and overseas.

While fireclay is still needed, there are now other producers, mainly China. For some reason the company P&M Hurll went into liquidation in 1980 and as a result mining ended. The workings slowly filled with water. The Bo’Ness Heritage Trust acquired the mine and operated it as a show mine. They were funded from the Falkirk District Council and when the Heritage Trust closed in the 1990s the responsibility for the mine transferred to Falkirk District Council. They closed the show mine permanently in 2013. As a result the mine is demolished and only the incline haulage track, the weighbridge building, and miners cottages still exist. The miners cottages have since been converted into a family home.

Bo'ness is situated on the foreshore of the River Forth, 8 miles west of Edinburgh, the visit to the mine is part of a short railway journey, from the town of Bo'ness to the mine and back again.

On the surface is a large three storey building, and the clay is hauled from the mine by old trams and then up a steep incline to the processing plant. From the railway station at the mine, the trip consists of walking down a stairway at the side of the incline and following the rails into the lower of 3 adits. This adit was started in 1932. Two other adits were driven, one for the haulage and the other for ventilation.

During the 1950s and 1960s work rapidly expanded and by the 1970s there were 6 miles of tunnels going 900 yards into the hill. The last mining took place in 1980 and for 7 years the mine stood empty. The conditions at the mine deteriorated and clay fell from the walls into the roadway and the deeper workings flooded. For many years the fireclay with its high alumina content was in demand for the production of fire bricks but as demand for this product decreased so the mine fell into disuse and in 1980 it closed. Many of the old tools were left in place and are on display today.

There is also a walk through Birkhill Woods and meadow. Although the mine is not suitable for wheelchairs the railway, the woods and meadow are. The guided mine tour lasts about 1 hour and free car parking, souvenirs, and refreshments are available at Bo'ness station.

Text by Tony Oldham (SEP-2001). With kind permission.