blast furnaces / Dortmund / 1854 - 1998 / 2006
One of the most famous post-industrial landmark of Dortmund is the couple of former Hörder blast furnaces. They used to be part of a large steel-making complex, which roots are traceable in the Hermannshütte company founded by Hermann Diedrich Piepenstock in 1841 and transformed into Hörder Bergwerks- und Hüttenverein Aktiengesellschaft in 1852. Two years later four modern coke blast furnaces were fired up, each with a daily capacity of 17,9 t. At the threshold of the 20th century two more blast furnaces were added and therefore the overall pig iron capacity increased up to 500000 t/y - more than 6000 workers were employed at that time. In 1906 the Hörder Vereins merged with Phönix Actien-Gesellschaft für Bergbau und Hüttenbetriebe zu Duisburg-Ruhrort - another Ruhr-based company -, giving birth to the largest German coal mining and steel-making enterprise. Twenty years later the latter was taken over by the national conglomerate Vereinigte Stahlwerke AG, active until the end of the Second World War.
Following the German iron and steel sector reorganization, in 1951 the Dortmund steel mill was taken over by Dortmund-Hörder Hüttenunion AG. The existing five blast furnaces were revamped and enlarged. Again, in 1966 the company was taken over by Hoesch AG. During the following decade two furnaces were shut down due to the sector crisis, anticipating the decline of heavy industry in the Ruhr basin. Run by Krupp since 1991, the plant was doomed for closure as a regional strategy aiming to concentrate residual steel-making activities in the city of Duisburg emerged. This happened in 1998: blast furnaces n.5 and n.6 were shut down, while n.4 was dismantled and sold to China. The ongoing reconversion project is transforming the former steelworks in a technology park. Blast furnace n.5, the large gasometer and a few buildings around will be preserved as industrial monuments.