On the evening of March 16, the cutterhead of the shield machine, weighing over 500 tonnes, was successfully hoisted and lowered into the shaft with the cooperation of two crawler cranes, laying a solid foundation for the planned launch of the "Yongping" shield machine for the Shantou Bay Subsea Tunnel on the Shantou-Shanwei Railway at the end of this month.

The huge cutterhead is slowly lowered into the shaft with the cooperation of two crawler cranes.

The "Yongping" shield machine consists of the main machine, cutterhead, shield body, one connecting bridge and four gantry cars, with an overall length of 160 meters and a total weight of 4,200 tonnes. The cutterhead is the largest and heaviest single component of the shield machine, weighing over 500 tonnes. Lowering the cutterhead into the shaft is the most difficult and risky procedure in the shield machine assembly process. Two large crawler cranes, with capacities of 750 tonnes and 500 tonnes respectively, worked together to lift the cutterhead from the ground and, through mutual cooperation, performed a "90-degree turn" in mid-air to slowly bring it upright. At this point, the 500-tonne crane withdrew, and the 750-tonne crawler crane alone hoisted the cutterhead, adjusting its position bit by bit to accurately lower it into the shield machine launch shaft, fitting the "giant teeth" onto the shield machine.

The Shantou Bay Subsea Tunnel on the Shantou-Shanwei Railway has a total length of about 9.8 kilometers and is China's first high-speed railway subsea tunnel with a design standard of 350 kilometers per hour and a large-diameter cross-sea shield.