Derwentcote Steel Furnace (NZ130566)

© Copyright Helen Wilkinson and licensed for reuse 

under this Creative Commons Licence.

Close by the banks of the River Derwent near the village of Hamsterley Mill can be found a rather important relic of the Industrial Revolution: the Derwentcote Steel Furnace. It is the oldest and best example of its type remaining in the world – a cementation furnace which turned wrought iron into high grade steel.

Of the remains that can be seen today on the site, the oldest parts date to at least as early as 1719; and the plant remained in use until 1891 when a more advanced form of steel production was developed. As for Derwentcote, it began as a forge (and mill) around 1719, with the furnace added c.1733. Various storage buildings were then added as the complex hit full pelt. Iron would be imported from Sweden, via the Derwent, and handy local resources (charcoal, coal, clay and sandstone) made it a perfect spot for its intended purpose.

The cementation process involved layering bands of iron bars and charcoal powder in the central cone. A fire was lit and the temperature raised to about 1,100°C in the sealed chambers, causing the carbon from the charcoal to diffuse into the iron. The whole process – including the cooling period – took three weeks, and produced 10 tons of ‘blister’ steel. The steel was then taken to the water-powered forge to be made into items such as tools – steel, of course, being preferable to iron due to its combined strength and flexibility.

For a time Derwentcote and the Derwent Valley were the epicentre of the British steel industry, but progress eventually overtook it. After it fell out of use the building endured a century of slow decline – until English Heritage restored it in 1990.

Currently an archaeological programme of investigation is examining a nearby row of ruinous cottages thought to have been occupied by the families of the furnace workers.