On the afternoon of April 30, as the last shield machine of Nanjing Metro Line 5 slowly pushed into Yunnan Road Station, the shield tunneling of the section from Shanxi Road Station to Yunnan Road Station was completed, marking the full tunnel breakthrough of the entire Line 5. Line 5 is now one step closer to full operation.

Line 5 starts from Fangjiaying Station in the north and ends at Jiyin Avenue Station in the south, passing through Jiangning District, Qinhuai District and Gulou District. It is an important urban trunk line running from southeast to northwest in Nanjing's urban rail transit network. The line is 37.4 kilometers long, entirely underground, with 30 stations, 14 of which are transfer stations, earning it the title of "transfer king." On March 31, the southern section of Line 5, 12.9 kilometers long, opened for initial operation, bringing Nanjing Metro's total operating mileage to nearly 473 kilometers.

The shield launching shaft for the section from Yunnan Road Station to Shanxi Road Station is located at Shanxi Road, with Hongqiao Station and Fujian Road Station to the north and Yunnan Road Station and Wutaishan Station to the south. The area is densely populated, making construction difficult. Since the four stations before and after Shanxi Road Station all lacked the conditions for shield construction enclosure, the shield bases for 5 stations and 4 sections (8 shield tunnels in total) were all centralized at Shanxi Road Station, with a single Shanxi Road Station supporting the tunneling production of 8 shield machines. This arrangement also minimized the impact of construction on road traffic and surrounding residents.

The entry and exit of 8 shield machines at a single site, along with long-term cross-over and three-dimensional operations for shield tunneling toward both sides, posed enormous challenges to construction organization and safety management. In particular, the cramped urban construction site required cross-station transportation, resulting in longer transport times and higher costs. Nanjing Metro strengthened overall coordination in personnel, technology, materials and equipment, overcoming difficulties such as numerous and widely distributed construction sites and complex construction techniques, and successfully achieved the tunnel breakthrough of Line 5.