On the afternoon of February 21, at the bottom of the shaft at the Xiangya Road river-crossing passage in Changsha, Hunan Province's largest diameter shield machine —— the “Xingsheng” —— successfully installed its “giant teeth”, marking the final stage of the main machine assembly. In early April, excavation for the Xiangya Road river-crossing passage will begin.

It is reported that the shield machine's cutterhead has a diameter of 15.01 meters, equivalent to a five-story building, and weighs nearly 500 tons. It adopts a heavy-duty composite cutterhead with high wear-resistant and high-strength cutting tools.

At around 10 a.m. that day, with the help of two large crawler cranes, the shield machine's cutterhead began to slowly rise from the ground, “turned over” in the air and gradually “stood upright”. At 2:12 p.m., a 650-ton large crawler crane hoisted the cutterhead and slowly lowered it into the 37-meter-deep shield launching shaft, successfully positioning it in place at 3:30 p.m.

As the cutterhead weighs nearly 500 tons, lowering it into the shaft is the most difficult and risky procedure in the entire assembly of the “Xingsheng” shield machine. Since the first batch of cutterhead components arrived on December 21, 2020, the Xiangya Road river-crossing passage project department of Changsha City Development Group has planned ahead and organized meticulously. During the Spring Festival, more than 180 people stayed on duty to ensure steady progress of all work.

The “Xingsheng” shield machine has a total weight of about 4,000 tons and adopts advanced technologies such as direct and indirect slurry discharge, efficient in-chamber crushing, and a telescopic main drive. It is one of the most advanced super-large diameter slurry balance shield machines in China, tailor-made by CRCHI in collaboration with China Railway 14th Bureau Group for the Xiangya Road river-crossing passage construction.