Ironbridge is most famous as the birthplace of modern industry in the early eighteenth century. But the industrial archaeology proves that the area around Coalbrookdale was an industrial hub from the middle ages, with the water powering early iron and steel works.
Coalbrookdale before the Industrial Revolution
The Coalbrookdale Watercourses Project is an ongoing survey of the ancient watercourses around Coalbrookdale. It has revealed that the area relied upon a water-powered system of industry as early as the Middle Ages.
The project has excavated and repaired a series of pools, all used to power early versions of heavy industry in the area well before the Industrial Revolution. Excavations show that the watercourse system was well established by the sixteenth century, with six pools powering four forges and two blast furnaces by the time of the Industrial Revolution.
A pumping station was also constructed to recycle the water in the late eighteenth century. But the advance of new technology meant the watercourse’s days were numbered and they went out of use in the early nineteenth century.
The First Steel Furnace in England
Industrial archaeologists from the Ironbridge Gorge Museum and Wilfred Laurier University also unearthed the first cementation steel furnace in England in the Ironbridge area in 2005. The furnace, which dates to around 1619, was the first of a series discovered in the area that were out of use by the 1680s.
The furnace produced “blister steel” used for tools and weapons. Circular in shape, it measured six metres in diameter. Two separate flues where coal was burnt to produce steel were excavated.
The furnace produced steel by carburising wrought iron bars in a charcoal-packed chamber. The carbon from the charcoal was absorbed by the iron during heating, producing steel — a technique discovered in Germany but pioneered in the Ironbridge area by Sir Basil Brooke.
Iron working and Ironworks
Basil Brooke was also the first to invest in ironworking in the Coalbrookdale area. Brooke’s family acquired the land around the Coalbrookdale valley after the dissolution of the monasteries. The industry he established provided the foundations for Abraham Darby to build upon.
There were possibly four early forging sites around Coalbrookdale that predate the industrial revolution. In 2002, an early blast furnace was excavated in the cellar of a pub in Leighton. This foundry gives some idea of how charcoal-fired ironworking was conducted in the area before Darby’s innovations.
The furnace was powered by water, as suggested by a waterwheel in the pub’s cellar and nearby watercourses. Some of the furnace was already visible in the pub cellar: brick courses that held the bellows, the remains of a blowing arch and a trench that would have directed the air from the bellows into the furnace.
Excavation of the car park unearthed the site remains of the foundry itself. Parts of the casting arch, which formed a base for the furnace, were excavated, as was the casting floor of the furnace itself, a sand-based area used to mould the liquid metal into pig iron.
As with so much of the pre-Industrial Revolution industry in the Ironbridge area, the furnace went out of use just as new coke-based furnaces were taking off in the area.
Resources:
The Time Team “The Furnace in The Cellar.”
