One of the major tasks of the project was to make several drainage cuts with a total length of 1,800 running metres, so that accumulating water can ideally drain off in the future.

The project proved to be perfect for the use of the Tyrolit ‘TEW’ tunnel mill, especially as it enables continuous and efficient semi-circular cuts. However, as Subterra had not worked with this tunnel mill before, Tyrolit organised cross border training on the use and maintenance of the TEW for the team in charge. The first part of the training took place at the end of February together with Tyrolit partner Brun AG in the Hagersbach training tunnel in Switzerland. At the beginning of March, the training was completed directly at the project tunnel near Brno in the Czech Republic. The entire training and the first days of the following operation were accompanied by Tyrolit project managers and application engineers.

During the actual use, the tunnel mill and the matching PPH40 drive were mounted on a specially constructed truck chassis. The cutter was equipped with four WSL ‘Premium’ wall saw blades with a diameter of 650mm and spacer discs with the respective widths. The goal was to cut three drainages per working day, a task the committed team also managed to do. In total, 1,800 running metres with a cutting depth of 20cm were cut with the Tyrolit TEW tunnel mill by mid-April. Thanks to good planning and shelving spare parts, the cutting works were completed without any interruptions to the tight schedule.