For “Unsere Grüne Glasfaser,” a railroad bore was conducted beneath the Deutsche Bahn in Sohren, located in the Hundsruck Hills range. Achieving the planned 120-meter radius posed a challenge due to the heavy soil class in Sohren, the limited length, and the use of a mud motor alongside the Paratrack measurement system featuring a 7-meter drill head.

Despite these obstacles, the bore was successful, with an average drilling time of 40 minutes per rod and a comparable duration for pre-reaming with the rollercone. The insertion of the Ø200mm pipe through the hard ground afterward proceeded smoothly. Due to the substantial amount of drilling fluid required for the mud motor, the drilling fluid was continuously recycled in the mix truck.