They rank on the Top 10 list of the largest tunnel boring machines delivered for infrastructure projects worldwide: the two Mixshields S-349 and S-350 with a diameter of 14.93 meters for the "Nanjing Yangtze River Crossing Project".

Nanjing, the capital of the Chinese province of Jiangsu, is an important transportation hub and bridgehead on the axis leading inland from Shanghai. In order to channel the rapidly growing traffic load, a three-lane, 2.9-kilometer-long road tunnel was developed beneath the Yangtze River. The tunnel is a key project for the city, with the aim of relieving the large Yangtze River bridge and advancing the urban development in the northern districts of the city and on the opposite side of the river. 

The two Mixshield giants have a tough job: They had to withstand water pressure of up to 7.5bar while working their way through gravel and silt layers, sometimes with overburdens of only 30 meters to the bed of the river. With cutting wheele spokes accessible under atmospheric pressure and with a torque of almost 35,000kNm, the machines are well prepared. The S-350 reached the breakthrough point in the left tunnel on May 20, 2009, the S-349 completed the right-hand tunnel on August 22, 2009.