Beijing, November 28 (Youth.cn) - Staffs were checking a shield tunneling machine in Chengdu on November 27th. The 14-meter-diameter shield tunneling machine named "Chengyu" set out from No.2 shield shaft in Shu'an Tunnel at the depth of 38 meters. It will carve out 4.56 kilometers' path. The mission that it will accomplish is an important part of high-speed railway net in China. Photo/VCG