The Herrenknecht TBM with a diameter of almost 14 meters broke through the other side of the Jura mountains after only 72 weeks. There was also a small statue of Saint Barbara, the patron saint of miners. On June 21, 2017, the Belchen tunnel, 3200 meters long, was pierced. The Herrenknecht tunneller, with a diameter of almost 14 meters, broke through the other side of the Jura after only 72 weeks. There was also a small statue of Saint Barbara, the patron saint of minors. On June 21, 2017, the 3,200-meter-long Belchen Tunnel was penetrated. The Herrenknecht TBM with a diameter of almost 14 meters broke through the other side of the Jura Mountains after only 72 weeks. There is also a small statue of Saint Barbara, patron saint of miners.