On June 29, good news once again came from the construction of Nanjing Metro Line 5. Following the achievement of short-track connection on June 19, the northern section of Line 5, after 10 days of intensive construction efforts, achieved long-track connection. With this, the first two important milestones of the metro construction "trilogy"—tunnel breakthrough, track connection, and power connection—have been successfully completed, and the project will fully enter the stage of electromechanical installation and systems engineering construction, striving toward the subsequent power connection.

On the morning of June 29, banners hung high and colored flags fluttered at the Chaotiangong track-laying base of Nanjing Metro Line 5. Builders gathered by Chaotiangong, known as a "famous historic site of Jinling," to jointly celebrate the long-track connection of the entire Line 5.

Nanjing Metro Line 5 has a total length of 37.4 kilometers, entirely underground, with 30 underground stations and an average station spacing of 1.26 kilometers, including 14 interchange stations. The southern section opened on March 31, 2024; track laying on the northern section began on June 30, 2023, and long-track connection of the entire line was achieved on June 29, 2024.

To complete the track-laying task of Line 5 on schedule, all participating units overcame difficulties such as limited time, heavy tasks, discontinuous work faces, difficulties in material delivery, and reduced mechanized track-laying bases. By introducing new equipment and increasing manpower and material resources, and by combining mechanized track laying with manual track laying, construction was launched across the entire line with multiple work fronts progressing simultaneously. He Zhipeng, technical director of China Railway 11th Bureau, the track unit responsible for the construction of the northern section of Line 5, introduced that during this year's peak track-laying period, 8 work faces were set up for simultaneous construction on a line of only 16 kilometers, with nearly 40 sets of track-laying equipment used and more than 600 personnel deployed. Through high-intensity accelerated track-laying construction, the milestone goal of long-track connection for the entire line was successfully achieved.

Nanjing Metro Line 5 is a backbone line running north-south through the main city and enjoys the reputation of "Interchange King." After the entire line opens for operation, it will effectively ease traffic pressure on north-south roads in Nanjing, greatly improve traffic conditions in the urban area of Nanjing, and be of great significance to improving Nanjing's overall traffic structure and accelerating urban renewal, development, and growth.

Previously, in order to facilitate tunnel breakthrough and track connection as soon as possible, Nanjing Metro stepped up the construction of stations and sections for important work points on key lines and strengthened external coordination. For example, within the construction scope of Yunnan Road Station there were numerous municipal pipelines, and many important pipelines had no relocation routes for various reasons. To meet the requirements of station construction and in-situ protection of municipal pipelines, this single station alone adopted three construction methods: open-cut top-down construction, covered excavation bottom-up construction, and mined excavation. Moreover, to ensure the safety of various pipelines during the construction of retaining piles, the station took various "detours" and "side paths" during foundation pit excavation, carefully avoiding existing pipelines, and completed the station retaining structure construction using multiple complex technologies and methods, thereby relatively smoothly completing the construction of this key station.

At the same time, Nanjing Metro closely monitored the clearing, surveying, acceptance, and handover of completed tunnels, and worked backward to set the start and completion times of each process. Concentrating efforts to solve various difficulties, it achieved partial withdrawal of enclosures at stations such as Xiaguan Station, Hongqiao Station, Yunnan Road Station, Shanghai Road Station, Sanshan Street Station, and Guanghuamen Station in the main urban area, returning roads to the public as early as possible and reducing the impact on residents' travel along the line.

The achievement of long-track connection for the entire Line 5 indicates that Line 5 has fully entered the electrification construction stage, bringing it one step closer to the goal of opening for operation.