Dannemora Mine and the Iron Ore

Dannemora Mine, dating back to the Middle Ages, has played a key role in Sweden’s economic and industrial development through history. The mine is famous for its high-quality iron ore, particularly the low-phosphorus variety used in steelmaking.  Mining for magnetite at Dannemora began at the latest in the 16th century, and in the 17th and 18th centuries Dannemora became one of the most important mines in Sweden. The bar iron that was produced from Dannemora ore in the Walloon Forges in the region around the mine was highly sought after and boosted Swedish exports. At the turn of the 18th century, production was around 18,000 tons of ore. 

 

The mine was a place of hard work but also early on became an attraction for foreign visitors, who came to witness the impressive operations, descend into the open pits, and be horrified by the deafening noise. ’The most violent and terrifying spectacle one can imagine,’ reported a visitor from England in 1774. Sweden became one of Europe’s leading iron exporters during the 17th and 18th centuries

 

Throughout the 18th and 19th centuries, improvements were made in mining and transportation technologies. This included the construction of infrastructure, such as railways, and the use of water-powered pumps to drain the mines. 

Dannemora remained important through the 19th and 20th centuries but faced challenges through tecnological changes in the steel industry. New mining technologies and new demands has led to a revival and an exciting future for Dannemora in the coming years.

 

The Walloon Forge at Österbybruk

During the early 17th century, the Uppland ironworks recruited skilled ironworkers from the Walloon region in present-day Belgium. Walloon forging focused on producing high-grade wrought iron using a specialized method with two separate hearths. Wallon forging was particularly effective in producing iron with low levels of impurities, ideal for making tools and weapons. 

 

The process starts by smelting iron ore in a blast furnace to produce pig iron, which is high in carbon content. In the smelting hearth, the pig iron is heated to a high temperature (around 1200–1300°C) in the presence of charcoal and air. The decarburization, turns pig iron into malleable wrought iron, which is lower in carbon and more ductile. The iron is reheated in the racking hearth which allows the iron to be worked into bar iron. 

 

The Wallon Forge at Österbybruk is the only preserved forge of its type, and a unique piece of industrial heritage. It is maintained and kept open to the public by The Österbybruk Manor Foundation.

 

Österbybruk Manor

Through the mine and the forge, the industrial community began to grow at Österbybruk. Housing was built for the smiths and workers, along with a school, church, storehouse, and office. And of course, a more stately residence was needed for the estate’s masters.

 

The first manor house was completed in 1610 and was a timber building for the estate’s managers. When the estate was leased in the 1620’s to Willem de Besche and Louis de Geer, the era of Walloon forging began. Louis de Geer was allowed to purchase Österby in 1643. By the 1700’s new times were coming. The estate owners had wealth and good taste and a number of manor houses began to take shape next to the bustling ironworks around Uppland. The finest architects were commissioned to design castle-like buildings and expansive park landscapes. The construction of the large manor house at Österbybruk was completed in 1780. The manor and park are amongst the finest examples of 18th century architecture in Sweden.

 

Österbybruk Manor, together with the Mine at Dannemora and the preserved Walloon Forge provide a unique insight into Swedish industrial history and a view towards the future.