Often used in road construction in China, eight Herrenknecht tunnel boring machines (TBMs) have now excavated almost 16km of tunnel in 20 months. The machines mastered challenging tunnelling stretches with small overburdens, crossing beneath the emerging metropolis of Wuxi, eastern China, to excavate the first two metro lines in the 3,000-year-old town on Taihu Lake, near Shanghai. Lines 1 and 2, with a total length of 58.5km, are expected to start operation in 2014. A total of five metro lines are planned.