Łódź High-Speed Rail project installs 35-ton sealing ring

Construction of the High-Speed Rail (KDP) tunnel under Łódź has reached a critical milestone. A 35-ton sealing ring has been installed in the starting chamber located in the Retkinia district.

The ring is essential for the safe operation of the Tunnel Boring Machine (TBM), which is scheduled to begin drilling toward the city center early next year. The component was installed with a precision tolerance of only ±5 millimeters.

According to Maciej Dutkiewicz from the Port Polska press office, the ring serves to control ground and groundwater pressure. By using liquid construction materials to fill the space between the tunnel lining and the soil, the ring helps prevent uncontrolled ground subsidence during the drilling process.