On November 3, the outlet TBM of the Lesotho Polihali Water Transfer Tunnel Construction Project fully transitioned from open-mode excavation to double-shield excavation mode, officially launching construction in the project's core section.

Since the outlet TBM began excavation, the project has consistently adhered to the basic principles of "safety first, excellent quality, and lean management," successfully overcoming multiple technical challenges including shotcrete and rock-bolt support in extremely fractured surrounding rock, in-tunnel track installation, and large-gradient material transport. Construction efficiency has continued to climb, with per-shift advance successively exceeding 26 meters, 31 meters, and 34 meters, ultimately setting a new record of 61.7 meters in a single day for open-mode excavation by a double-shield TBM of the same diameter. This not only ensured that key milestone dates were met on schedule, but further strengthened the confidence of all project staff to overcome difficulties and keep making breakthroughs.

This double-shield excavation task covers a total distance of 33.7 kilometers. The project is equipped with two double-shield TBMs with a diameter of 5.35 meters, conducting opposing excavation operations from the Polihali inlet and the Katse outlet respectively. Next, the project team will continue to uphold its original aspiration, take responsibility and act, and strive ceaselessly toward the goal of achieving high-quality full-line breakthrough of the project.

Project outlet construction site