The "Fuchsbau" from 1943 to 1945
My graphic will illustrate how the bunker was planned in 1943.
From October 1943, the concrete tubes of the bunker for the Waffen-SS were built in the forest near Rauen.
Camouflage name "Fuchsbau", which was still to be built at another location during the summer.
The structure with its parabolic concrete tubes was simply placed on the edge of an existing gravel pit for reasons of cost and time.
Here, in just one year, the most important underground telecommunications center for Himmler's SS was built.
The shell was to be protected against air raids with a 25 m thick covering of 500,000 m³ of sand and 2 thick bomb protection plates. For this purpose, an entire hill was specially removed.
When construction work had to be stopped in March 1945 because of the proximity to the front, the building was unfinished on the outside, covered only in some places with 7 m of sand, but fully in operation until the end of the war.
Through reports of a 100-year-old engineer from the then leading construction office of the "Fuchsbau" from 1943, officers and soldiers who served in the "Fuchsbau" until 1945, as well as the examination of construction documents that were thought to have been lost and records of company employees involved in the construction, there is now clarity about the purpose, planned appearance, the construction process and the function.

Thus, the SS in Oranienburg began planning for its underground intelligence center and had the bunker "Fuchsbau" and a radio barracks from autumn 1943 finally on the eastern slope of a former gravel pit in the Jagen 116 of the Rauen mountains build.
Despite several changes in planning and a constant shortage of materials, after only one year of construction, in November 1944 the service operation in the bunker aufgenommem be.
One began still with the overfilling of the tube system.
By the end of the war, however, the complex remained unfinished on the outside.
The two shattering layers to protect against bombs and an extension of the staff tunnel by another 50m could no longer be realized.
Of the two stair tunnels of the emergency exits on the west side, only the lowest sections could be built.
Most of the space was taken up by the communications equipment.
Only the director of intelligence and his chief of staff had separate duty rooms in the south section of the bunker.
By the end of 1944, the Waffen-SS had developed its own teletype network, which spread like a spider web between Riga, Warsaw, Prague, Vienna, Munich, Metz, Apeldoorn and Berlin.
The newly laid guide cables of this network converged in the "Fuchsbau", which was placed under the command of the Führungsnachrichtenabteilung 501 of the Waffen-SS as late as October 1944.
At the end of the war, under the command of Obersturmbannführer Erwin Schumacher, high-ranking officers of the Wehrmacht were also able to visit the bunker.
When the tanks of the Red Army approached Fürstenwalde in April 1945, the last SS units left the "Fuchsbau" in the direction of Zossen and rendered the technology left behind useless.
The equipment and building materials were later dismantled and individual tunnel sections were blown up by Soviet troops.
The remains were largely utilized by the population in the destroyed Ketschendorf and other places.
The construction managers responsible for the Fuchsbau bunker were SS men and survived the war.
One of them continued his construction company in West Germany.
The other posed as a concentration camp prisoner and became the head of an institute at the GDR's Bauakademie.
After moving to the western part of Germany, he held leading positions at numerous large construction sites and did not die until 2001.
All the information given here is documented. A later publication is planned.