Recently, it was learned from Nanjing Metro that the final component of the "New Journey" shield machine for Phase II of Nanjing Metro Line 4—the shield tail—will arrive smoothly at the Jiangxinzhou construction site, marking that the assembly of the shield machine is about to be completed and that the launch of the shield machine has entered the countdown stage. At that time, the shield machine will tunnel 43 meters underground, creating a convenient passage connecting the north and south banks.

It is reported that the "New Journey" shield machine is 120 meters long and weighs 2,100 tons. The high-precision gas-liquid pressure balance control technology for the excavation chamber, the high-pressure flushing system, and the automatic pressure balance technology for drive seals equipped on the shield machine are ** configurations among river-crossing metro tunnels in Jiangsu Province. The "two-component grouting" technology adopted is the first application in a domestic metro river-crossing tunnel, which can effectively improve the quality of tunnel formation and ensure construction safety. It is understood that after the assembly of the shield machine is completed, it will set off from the Jiangxinzhou working shaft, then pass beneath the Jiangxinzhou Yangtze River levee, and then successively pass beneath Qianzhou and the Yangtze River, before completing reception at Binjiang Station in Jiangbei New Area. The line is 3,062 meters long in total. After the entire line is completed, it will connect the core area of Jiangbei with the main urban area of Gulou in Jiangnan.

The launching shaft at Jiangxinzhou for Phase II of Nanjing Metro Line 4 is 43 meters deep, which places very high requirements on the safety factor of shield machine hoisting. Nanjing Metro has held multiple expert review meetings, continuously refined the construction plan, and strictly controlled every procedure and every operation of shield machine assembly to ensure that the construction steps meet the specification requirements. Next, Nanjing Metro will make full efforts in construction work such as shield machine debugging and negative ring assembly, laying a solid foundation for the subsequent launch of the shield.

Phase II of Nanjing Metro Line 4 is Nanjing's third river-crossing metro line. The project starts at Zhenzhuquan Station and ends at Longjiang Station, with a total length of 10 kilometers, all underground, and 6 stations, including 2 transfer stations. As of May, all 4 stations and the intermediate ventilation shaft of Phase II of Metro Line 4 have started construction; 3 stations and the intermediate ventilation shaft have completed the retaining structure and main structure; and 6 shield tunnels have been launched and completed.