Forced labour in a hidden factory near Hildesheim owned by the Bosch corporation

Shadow factories 
 

The Bosch factory near Hildesheim was one of two major “alternative plants” (Ausweichswerke) owned by the Stuttgart-based Bosch group. Bosch was a market leader in the production of fittings for motor vehicles and aeroplane engines, making it a key player in the provision of armaments for the German Reich. Its injection pumps, starter motors and magnetos in particular were indispensable for the war preparations being organised by the National Socialists. For this reason, representatives of the new government already contacted Robert Bosch in 1933, the year the party took power. Due to its proximity to France, the area around Stuttgart, where the Bosch group operated its main factories, was considered too difficult to defend militarily. The company was therefore asked to build new production sites in a safer region in the German interior.[2] 

Bosch agreed, and in the following years founded two secret armaments factories in the interior. It began by building a factory with the cover name Dreilinden Maschinenbau GmbH in Kleinmachnow outside Berlin, where electronic aeroplane equipment was produced for the German air force (Luftwaffe).[3] Two years later, Bosch decided to operate an alternative plant in Hildesheim. This factory, which bore the innocuous name Elektro- und Feinmechanische Industrie GmbH (ELFI) was also used exclusively as an armaments production site. 

Bosch was not the only company to build alternative plants during the initial years of NS rule. According to a report produced by an American in 1943, the National Socialists began pursuing a policy of duplication and decentralisation of armaments companies right from the beginning. “Construction of additional factories was not permitted if plants were already in existence, particularly if these were situated in the vulnerable western regions of Germany.”[4] Rather, companies that were of key importance to the armaments industry were required to build alternative facilities elsewhere. These “shadow factories”, as they were called by the Americans, were built under utmost secrecy and in close collaboration with the NS authorities.[5]

Production was already underway in 1935 at Dreilinden Maschinenbau GmbH (DLMG). Bosch was also instructed to build an alternative plant far away from the borders of the German Reich in order to build engines for the army. Therefore, in the spring of 1937, the German army ordinance office (Heereswaffenamt) approached the company once again. However, while Bosch had built DLMG from its own funds, the company was now offered an extremely attractive funding model for the alternative plant in Hildesheim, which relieved the financial burden on the company and minimised its risks: the “Montan schema”. According to this plan, a private company received an order from the relevant army office of the supreme army command to build an armaments factory funded by the Reich. The owner of the new plant was the Verwertungsgesellschaft für Montanindustrie GmbH, a trust company of the army ordinance office. This trust company rented out the finished plant facilities to the private company commissioned by the army. In turn, the private company founded an affiliate and pledged to install and operate the new factory using the necessary knowledge and skills. In this way, the army ordinance office ensured that private industrial groups producing goods that were important for the military would continue to operate the factories even if this did not appear to be profitable in the long term. In addition, these factories were given preferential treatment when it came to disbursing labourers, raw materials and energy. By the end of the war, 119 of these operations had been established.

In order to protect the hidden factory from discovery by reconnaissance aircraft, ELFI, like the DLMG, was built in the forest. The buildings were relatively small and were made to look like a group of houses. With their modern lanterns and saw-toothed roofs, the bright, well-ventilated red brick halls conformed to the latest building standards at the time. One of the former forced labourers described the factory: 

“It was located in the deepest part of the forest, and was built in such a way that a small forest grew out of every roof. There weren’t any trees, but there were shrubs. And together with the big trees, these shrubs acted as a camouflage. That’s why the factory was never hit, even though there were bombing raids. The site was kept beautifully. I hope the factory is still standing today; I don’t know what the site is used for now. But the Germans surely wouldn’t have destroyed something so beautiful.”[6] 

In fact, Bosch still uses the red brick halls from the 1930s as a production site today. The former “workforce building” (Gefolgschaftshaus) is now home to the factory canteen.

During the course of the war, the plant was expanded and at the end of 1942, it was renamed Trillke-Werke GmbH after a nearby stream. The factory was given its own railway line, with which the strategically important sets of equipment were delivered to the companies that produced tanks. There was a particularly intense increase in production in the forest near Hildesheim after the invasion of the Soviet Union and the initiation of the “Adolf Hitler Tank Programme”, which aimed at doubling the planned tank production targets to date. From October 1943 onwards, the Trillke plant had a monopoly in the sector, arming all the new tanks used by the Wehrmacht with starter elements and other electrical fittings.[7]