The task of the Herrenknecht Mixshields "Shen Chong" and "Shen Tong" is to cross under the Yangtze River in Shanghai. They excavate a total of impressive 16,762 meters (9,024 for Lot 111 and 7,738 for Lot 108) and make way for a total of 22.4 kilometers of railway line. The South Port (Nangang) Tunnel will connect Jinji Road Station with Changxing Island as part of the Chongming Line.

On their long journey under the Yangtze River, the machines will encounter a sandy silt and fine sand layer, water pressures of 6 bar and a minimum curve radius of 1,000 meters. The cutting wheels of the two TBMs have been adapted to the geology and designed with a particularly high opening rate. A cutter tool change is possible under normal pressure. The integrated wear detection system makes the management of the changes efficient. The machines were also equipped with appropriate detectors in order to be able to react safely to possible gas deposits. Finally, there is the proven Herrenknecht SSP (Sonic Softground Probing) advance exploration system.