The Chinese government has launched the "Pearl River Delta Water Resources Allocation Project" to ensure the water supply of the densely populated Guangdong-Hong Kong-Macao region in southern China, even in an emergency. The cities of Foshan, Guangzhou, Dongguan and Shenzhen are to be supplied with water from the Xijiang River in future. The total length of these transport pipelines is 113.2 kilometers.

A total of seven Herrenknecht tunnel boring machines are being used for this large-scale project. One of these machines, a Mixshield with a diameter of 8.61 meters, is tackling part of the particularly challenging construction section B3. The tunnel crosses the Guangzhou Metro Lines 4 and 18, the Guangzhou-Shenzhen-Hong Kong Passenger Dedicated Line and the Dongguan Metro Line 2. The tunnel also passes under the Beijing-Zhuhai Highway, the Yanjiang Highway and the Guangzhou-Shenzhen Highway. 

The Herrenknecht Mixshield will drive 3,398 meters of this route and cope with water-rich fracture zones with up to 7 bar water pressure. A monitoring system monitors wear on the cutter tools, especially in hard rock layers. In addition, the wear protection of the pipes and the flush system were optimized for this application.