On December 26, as the cutterhead descended slowly along the launch shaft and docked precisely with the main drive of the shield machine, the cutterhead of the "Jincheng No. 1" shield machine for the Jingu Haihe Tunnel—the only shield tunnel on the entire Tianjin-Weifang High-Speed Railway line—was successfully hoisted down the shaft and assembled. The project is undertaken by China Railway 14th Bureau Group.

The "Jincheng No. 1" shield machine is currently the slurry balance shield machine with the longest single-head excavation distance and the largest excavation diameter in Tianjin. Its cutterhead is painted with a pattern of the "Ruyi Jingu Bang" (the golden cudgel). It was independently developed by China Railway 14th Bureau Group in collaboration with CRCHI (China Railway Construction Heavy Industry). With an excavation diameter of 13.8 meters, a total length of about 120 meters, and a total weight of about 3,200 tons, it is equivalent to 474 "Jingu Bangs."

The rollout site of "Jincheng No. 1"

Since the shield machine rolled off the production line in Changsha, the construction team has spent more than 60 days completing a series of operations, including disassembly, transportation, and reassembly of the shield machine. The cutterhead is an oversized and overweight component, and hoisting it down the shaft is the most difficult and highest-risk procedure in the shield assembly process. The construction team held detailed discussions on construction aspects such as the cutterhead welding method, hoisting position, and crawler crane selection, so as to ensure the hoisting operation proceeds safely and efficiently to the greatest extent possible.

In the future, the "Jincheng No. 1" shield machine will launch in an ultra-shallow cover stratum with only 8.5 meters of overburden and bore 6,014 meters northward in a single-head drive. During this period, it will pass beneath a series of major risk sources, including the Central Avenue Overpass, the Haihe River, and a seismic fault zone.

As an important part of China's "Eight Vertical and Eight Horizontal" Beijing-Shanghai auxiliary corridor and coastal corridor, the Tianjin-Weifang High-Speed Railway starts from Tianjin Binhai Station in the north and ends at Weifang North Station of the Jinan-Qingdao High-Speed Railway in the south. It is a key project for further implementing national strategies such as the coordinated development of the Beijing-Tianjin-Hebei region and the development of the Yangtze River Economic Belt, and for improving the comprehensive transportation system of the Beijing-Shanghai corridor.