The project was driven by the fuel needs of the German army at the last phase of World War II due to decreasing conventional petroleum supplies.
[1] Kohle-Öl-Union von Busse KG, established on 30 July 1943 in Berlin, tested in-situ retorting on the outskirts of Schörzingen.
[4] For the Operation Desert construction of ten shale oil extraction plants in Württemberg and Hohenzollern were ordered by Edmund Geilenberg.
Prisoners from seven nearby subcamps of the Natzweiler-Struthof concentration camp, established by the route of Tübingen - Aulendorf and Nebenstrecke Balingen- Rottweil railway lines, were used as a workforce.
[4] The main contractor for building these plants was Deutsche Bergwerks- und Hüttenbau GmbH, a subsidiary of Reichswerke Hermann Göring.