At 9:00 AM on November 28, the Lesotho Polihali Water Transfer Tunnel Project reached an important milestone—the "Dayu·Changfeng" TBM officially advanced toward the launch chamber, marking a new stage in the project's construction. This TBM is the first TBM used by Sinohydro Bureau 11 Co., Ltd. in Africa.

The main tunnel of the Lesotho Polihali Water Transfer Tunnel Project has a total length of 38 kilometers, with a TBM excavation section of 34.4 kilometers. The design calls for two TBMs excavating toward each other. The "Dayu·Changfeng" TBM advancing on this occasion is a double-shield hard rock TBM with a total length of 425 meters, a total weight of approximately 1,500 tons, and an excavation diameter of 5.35 meters. It was custom-designed and manufactured to address the project's characteristics and challenges, including "ultra-long single-head excavation, high overburden with ultra-high-hardness surrounding rock, and multiple water-rich fault fracture zones." The TBM is equipped with a data monitoring and recording system (TPC), a high-precision laser guidance system, a heavy-duty hard rock cutterhead, and a high-strength main drive and main bearing, among other state-of-the-art international technologies, ensuring that the equipment can operate stably and excavate efficiently even when encountering complex adverse geological sections.

The main body of the "Dayu·Changfeng" TBM weighs approximately 600 tons in total and is scheduled to take 3 days to advance to the launch chamber. Its stepping mechanism is precisely constructed with clear division of functions, covering large and small sliding plates, telescopic cylinders, adjusting cylinders and lifting cylinders, stepping pump stations, and more. During the assembly of the "Dayu·Changfeng" TBM, the project department adhered to the overall approach of "assembling while stepping" and "assembling outside the tunnel, launching inside the tunnel." Faced with adverse factors such as a confined site and the complex climate of a plateau region, they fully tapped the potential of the limited space available and, together with domestic and international experts, held multiple special meetings to determine the assembly plan best suited to actual site conditions and highly operable, providing a guarantee for the steady progress of the project's construction.

Currently, assembly of the "Dayu·Changfeng" TBM is 60% complete. Subsequent work will include the connection of electrical, hydraulic, and piping systems and full-machine commissioning. The ancillary supporting facilities—including the continuous belt conveyor, horizontal transport locomotives, high-voltage power supply system, water supply and drainage system, ventilation system, and segment precasting plant—are all in place, and the TBM is expected to meet launch requirements in January 2025.

The Lesotho Highlands Water Project is the largest bilateral infrastructure project between Lesotho and South Africa. It is implemented in four phases and is planned to direct the abundant water resources of Lesotho's mountainous areas to water-scarce regions of South Africa through the construction of a series of dams and a complex tunnel network. The Polihali Water Transfer Tunnel Project is the main works of Phase II of the Lesotho Highlands Water Project. It is implemented by a joint venture led by Sinohydro Bureau 11 Co., Ltd. together with Sinohydro Bureau 3 Co., Ltd. and the South African local enterprise UNIK. The advancement of this project has not only promoted the integration of diverse cultures and management concepts, but also enhanced the company's internationalization level in contract management, performance execution, safety production, and technological innovation, making a positive contribution to building a higher-level China-Africa community with a shared future.

Assembly site

Group photo of construction staff