Federal Fortress Ulm-Hauptwerk Oberer Eselsberg

The Federal Fortress of Ulm, to which the Main Work Oberer Eselsberg belongs, was one of five major federal fortresses financed and constructed by the German Confederation in the 19th century. Its completion occurred in 1859. The design of the Ulm fortress, which with a polygonal main rampart of approximately 9 km represented the largest fortification of its time, originated from the Prussian fortress construction director Moritz Karl Ernst von Prittwitz und Gaffron, who created the designs between 1842 and 1859 and supervised the construction. Up to 10,000 workers were involved in its erection. The Main Work Oberer Eselsberg itself was built later, from 1881 to 1887, as an almost symmetrical lunette under the direction of Lieutenants Küster and Lehmann, capable of accommodating up to 750 soldiers. Around 1903, it was converted into a pure infantry work, and in 1914, it was integrated into the main battle position as strongpoint 29.