in detail
The city of Friedrichshafen at the Lake of Constance and its industries, which were originally founded by Graf Zeppelin, became a target for Allied bombs during World War II. At that time, the factories in Friedrichshafen operated almost solely for the armaments industry. Due to the bombings, the assembly and testing area for the V2 rockets had already been removed to the north German region. The most devastating bombardment hit Friedrichshafen on April 28, 1944 and led to the decision from Berlin not to rebuild the essential war operations in Friedrichshafen, but rather to reestablish them underground.
"The Reich Ministry for Munitions and War Production" mobilized a consortium of construction firms to construct tunnels in Überlingen at the Lake of Constance to contain the underground factory.
Concentration camp prisoners from Dachau were brought for labor in the fall of 1944 and built their own concentration camp (satellite camp) northwest of Überlingen near the village of Aufkirch. The concentration camp contained about 800 prisoners who in less than seven months blasted through the rock near the Überlingen West train station creating almost four kilometers of tunnels. Day and night, in two shifts of twelve hours each, the prisoners drilled, blasted, loaded material on to trucks and dumped it in the Lake of Constance. The firms Luftschiffbau, Maybach, Dornier and Zahnradfabrik (ZF) were to be established in separate "bombproof" factories served by train and road links. But production never began because in April 1945 the French reached the Lake of Constance. About 180 prisoners did not survive the hardships of the exhausting labor. Ninety-seven of them were buried in 1946 in the concentration camp cemetery in Birnau after their bodies had been covered by earth in a mass grave for over a year.
The material which had been dumped in the Lake of Constance formed a land deposit in the lake near the railway tracks upon which the Überlingen camping site has been established. The tunnel complex is for the most part intact and can be visited by request. In front of the entrance (Obere Bahnhof Strasse), near the former camp (Härlenweg) and at the concentration camp cemetery (B-31 in Birnau), there are information panels and monuments. A documentation center is being planned for the tunnel area.
Winter 1944-45
An underground system of tunnels, built by 800 prisoners from the Dachau satellite concentration camp Überlingen, is to be used as an armaments factory. It encompasses approximately 4 kilometers of incomplete passage ways.
After 1945
The tunnels are partly used as a depot for boats.
Since 1984
There is a memorial site outside the complex and another located at the former concentration camp. A concentration camp cemetery is near Birnau.
Group tours through the tunnel that is equipped with illustrated information panels are available. Advance reservation is necessary.
Schaffhausen, March 3, 1945, Concentration camp prisoners after escaping from the Überlingen Concentration Camp to Schaffhausen, Franz Allmeyer, Polizei Kanton Schaffhausen.
Schaffhausen, 1990er, A view inside the mines, Franz Allmeyer, Polizei Kanton Schaffhausen.
