With the order of the High Command of the North Sea Naval Station on April 20, 1944, the military expansion in the German Bight began following instructions from Berlin. This step was taken because an invasion of the Dutch and German North Sea coasts by the Allies could no longer be categorically ruled out. It was then decided to develop the affected coastal strip into a fortress with various construction measures in order to be able to fend off a sea-side attack if necessary. These included bunker construction, barbed wire and mine fields, the construction of ring positions, but also the construction and expansion of heavy gun emplacements. In Altenwalde, among other things, an artillery position was planned between the streets "Zur Burg" and "Immenweg" on what is now the sports field. The position consisted of four 15.5 cm K 418(f) captured guns from French production. They stood on a frame that was pivoted in a bed. The battery was reported ready for use as early as November 1944, but it was never used. According to contemporary witnesses, the guns were withdrawn at the end of the war in April 1945 and assigned to a combat group for use against advancing Allied troops in the Elbe-Weser-Ems region.