When designing new circular processes, it can be useful to learn from the past. I discovered Freudenberg and its excellent Technikmuseum on a visit to the Siegerland region (east of Cologne). The museum is home to a steam engine from 1904 that had been used in one of the glue factories in this town. The museum association not only presents the working steam engine together with an impressive full mechanical workshop of functioning saws, cutters, drills and more. They also documented the development of the different trades in their hometown - an excellent example for early industrialization.

Steam power!

The central factor for the development of this particular circular economy was the already existing “Haubergswirtschaft” typical for the Siegerland region. It consisted in a type of communal forest management that used oak and birch to produce charcoal for the abundant iron ore industry of the region, and it was the bark of these trees that was used in tanneries since the 14. century. Skins were available in great number from the animals used to transport the iron ore.

Early on the production of glue from the rests of these skins was a sideline activity for the tanners. Starting in the 19th century, specialized factories were built.

In the tanning process, the animal hair was at first used as fertilizer. Later, a more profitable use for felt production was developed and a number of felt factories was opening in the town.

While reading through the booklet I bought in the museum, I was actually impressed how every waste stream coming out of a process was turned into a new resource - and how people sought to develop new technologies to make better use of these resources. I believe that it was actually during the decades of cheap oil and synthetic materials in the second half of the 20th century that we lost the need (and skills) to find a usage for each and every waste stream of industrial processes, but I still need to learn more about the industrial processes of those decades to be sure.

Another surprise was the complexity of some of these early machines. For example, a machine sharpening the blades of circular saws: turning the blade as well as turning the polishing disc and changing its angle, all at same time! I don’t want to imagine designing such a mechanism without the help of CAD!

These connections between industries worked as a circular economy till the 18th century, after which the import of skins from South America started. Most factories started to use mechanized processes and installed steam engines working not with charcoal, but mineral coal, which enabled the mechanization of many processes before done manually. The growth of the town’s industries led to an increasing pollution of the small river where most of the factories were located. The pollution problem improved only in the second half of the 20th century, when ecological considerations became more important, and when most of the leather, glue and felt industry went bankrupt (new environmental constraints together with the introduction of synthetic materials led to a reduction in demand and a relocation of industries to developing countries).

There are a few factors that remain unknown. I would like to know more about how the workload for individuals developed during the centuries. We know that manual labour in these industries used to be hard and each industry had its associated diseases (Anthrax in the case of the tanners, who worked with raw animal skins, lung disease in the case of miners and other workers who spent their days in environments full of dust or fibres, hearing problems due to noisy machines etc.) More details about the lives of workers would be useful if we want to find out how much industrialization and what kind of technologies we would want to see in the future, to not return to the hard and unsanitary work conditions of the past while avoiding irresponsible pollution and exploitation of resources, and maintain a certain comfort level.