The beehive coke ovens that lie in ruins at Woodmuir Farm are named after their distinctive dome shape.
These ovens were used for a process called coking, where coal was transformed into coke, a more efficient fuel, by slow controlled burning. Although coke had various uses, in the 19th century its primary use was as fuel for blast furnaces such as the Wilsontown Ironworks.
This photograph shows a beehive oven with its front removed so you can see inside where the coal was heaped. The ovens show evidence of burning and each has a vent hole at the top.
History of the site
As yet little is known about the history of this site. Historic map evidence tells us that the ovens were built sometime during the 19th century; they are not evident on the 1856 Ordnance Survey map but are shown on the 1898 edition. The later map illustrates that there was coal mining in the immediate area and the ovens were no doubt connected with that business.
Cottages for the miners, as well as a school for their children, stood where the Forestry Commission car park is now located. Early maps show both old disused shafts and working shafts in the area, suggesting a lengthy history of coal mining. It makes sense that at least some of these mines would have supplied the ovens.
Visiting Woodmuir Farm Coke Ovens
The exact location of Woodmuir Farm Coke Ovens is grid reference NS 968 598, and can be found off the A704, near West Calder, West Lothian, EH55 8JW. UK
All sites managed by Forestry Commission Scotland are open for you to explore. However, not all sites have paths or signage and some are a considerable distance from car parking. We recommend that visitors consult a detailed map and wear appropriate clothing.
Please follow the Scottish Outdoor Access Code and remember that historic sites should be treated with care and respect.
Coking: from wood to coal
Coking fuel is an ancient practice. In early times wood was coked to make charcoal. Roman writers mention charcoal fires burning in the temples of the ancients.
The first written record of coking coal is in 1620 when a group lead by Sir William St John invented and patented the first beehive coke oven. Over the following 200 years a further thirty-five patents for beehive coke ovens were submitted, each offering fresh improvements.
At first, however, iron production did not use coke, because the impurities in coal affected the quality of the iron. In the 17th century Dudd Dudley experimented with using coke for iron production, with some limited success, but it was not until 1709 that the coke smelting process was perfected by a Quaker called Abraham Darby, in Coalbrookdale, Shropshire.
A primary fuel
By the beginning of the 19th century coke had become the primary fuel for producing iron, dramatically changing this industry in Scotland. Whereas blast furnaces were once based in the Highlands - where oak woodlands provided charcoal fuel - coke-fired furnaces were now built in the central belt, where there was plenty of coal to be mined.
The coking process
On reaching the remains of the ovens at Woodmuir Farm you will see that the fronts of the oven have been lost. This, however, gives a view of the inside of each oven to see how they operated.
The principal process of producing coke using coal did not really change from the way people made charcoal from wood.
Civil Engineer Paul Mallmann described the process at a presentation on the history of the coke oven to the Cleveland Institution of Engineers in 1904:
"The coal to be coked forms a heap in the Oven, and is ignited by the heat reflected from the dome, which retains its heat, whereas the side walls are cooled by quenching the Coke in the Ovens itself"
The process heats the coal but does not allow it to burn. While the principles are similar, coal coking is far more complicated than charcoal making. You can see this by comparing the archaeological remains of the charcoaling process at Bonawe to this site.
The long history of patent records outlines the continuous inventions of better methods and designs for the coking ovens. The attempts to develop and improve the coking process continued into the 20th century.