The purpose of this project was the completion of the development works at the new underground lime mine »Mähringer Berg«. In 2000 and 2001, the main roadway of 190 m, parallel roadway of 60 m, and a crosscut of 28 m between both entries were driven. The parallel roadway floor lay about 4.5 m above the main roadway floor. The development pursued the planned extraction using the pillar construction method.

The entry to the mines happens via parallel roadway, from the bottom level of which the mines will be extracted by use of benches. The mines are 10 m high and spare pillar with a cross-section of 10 x 10 m at an interval of 8 m. The road headings were proceeded by drilling and blasting. The designated drilling and blasting scheme was optimized in advance by blasting tests, and adjusted further during the drifting in order to reconcile the requirements of both client and contractor. The advance per round and a slight explosive consumption were decisive for the contractor while the client attached importance to the big fragmented size of the spoil to be able to realize it directly. Because only very stable rocks were in the previous road headings in the new mining section, no support was planned for producing the conveyor road and parallel roadway. During the drifting, however, deep and clay-filled fissures were consistently encountered in both roadways required active security. This was realized with a locally adapted combination of shotcrete, reinforcement mat, and 1,5 m Swellex anchor. The shotcrete was initially placed as bagged cargo using a small spraying machine Meyco Piccola, which was kept on site for smaller works. The performance of the Meyco Piccola was no longer sufficient to meet the demand for shotcrete protection, which had risen sharply in the course of the drifting due to the poor geology, and it was converted to a pressure silo (10 bar) from Rombold & Gfrörer with a spray line underground. The dry spraying method was also retained for the subsequent work. The device park inserted during drifting includes vehicles in particular: 1 drill jumbos Atlas Copco AC Rocket Boomer 352 (2-arms with basket), 1 Komatsu WAV 470 wheel loader with 4 m³ bucket, 2 TEREX TA 30 skips with 17.5 m³ skip capacity, 1 Schaeff TEREX ITC 312 H3 tunnel loading and robbery excavator, 1 Merlo (platform and transport vehicle) and two T4 transporters (explosives and vehicles). The work was done as parallel drifting in the main and parallel heading at the same time with an output of 3 to 3.5 rounds per day. After the successful cut-through, the contractor executed further missions extended the planned construction period from 10 months to a total of 18 months.