On October 15, 2025, the Jiangsu Provincial Public Resource Trading Network released a heavyweight announcement, announcing the winning results of the two major sections of the Nanjing Metro Line 1 power supply system equipment renovation project. China Railway Second Bureau Group Electric Engineering Co., Ltd. and China Railway Electrification Bureau Group Co., Ltd. won the bid for section 1 and section 2 respectively, marking the substantial promotion stage of this "transportation artery" revitalization project that has been in operation for nearly 20 years. As the first subway line to open in Nanjing, the track and power supply renovation of Line 1 is the core link of its entire system upgrade, with a total investment of over 290 million yuan, covering key sections such as Maigao Bridge to Pharmaceutical University and the original West Extension Line.

The winning bid for the power supply renovation project focuses on the dual goals of "strengthening the foundation" and "smart upgrading" of the system. Section 1 will comprehensively update the substation system of Line 1 Phase I and South Extension, replacing core equipment such as 0.4kV switchgear frame circuit breakers and 35kV protection devices, and adding an intelligent operation and maintenance system for the substation; The contact network system focuses on updating flexible and rigid suspension contact wires, load-bearing cables and other wires, as well as components such as ratchet compensation devices and segmented insulators. At the same time, a visual grounding system and a five prevention interlocking system are added to the entire line. Although the specific renovation details of Section 2 have not been specified, a construction period of 1522 calendar days is set in sync with Section 1. It is expected to complete the upgrade of power supply facilities in the remaining sections and form a coordinated support network for the entire line.

Track renovation focuses precisely on addressing the issue of line aging. As a backbone line with an average daily passenger flow of nearly one million, after 20 years of operation, some sections of Line 1 have experienced joint losses and track bed settlement. This renovation will use new wear-resistant steel rails to replace old sections, fine tune the geometric dimensions of the track, and improve the stability of the line through measures such as strengthening the track bed and updating fasteners, laying the foundation for subsequent train speed increase and transportation capacity improvement. It is worth noting that the winning companies all have rich experience in rail transit renovation - China Railway Electrification Bureau has participated in the construction of power supply systems for major projects such as Beijing Metro Line 12 and Nanjing Metro Line 5, while China Railway Erju Electric Power Company has multiple benchmark cases in the field of railway electrification engineering, and its technical strength provides guarantees for project quality.

This renovation will strictly follow the principle of 'non-stop construction', "said the person in charge of Nanjing Metro Operation Co., Ltd. The construction will mainly be arranged during the nighttime shutdown period and holiday window period, and the impact on citizens' travel will be minimized through segmented operations and rapid connections. After the project is completed, it can not only solve the safety hazards caused by equipment aging, but also achieve accurate warning of power supply faults through intelligent operation and maintenance system. Combined with the improvement of track flatness, it can further enhance the smoothness and punctuality of train operation.

According to the plan, the renovation of the track and power supply will be carried out synchronously with the upgrade of the previously launched electric passenger cars, communication signals and other systems. The overall project is expected to be completed by the end of 2030. At that time, this subway line carrying the memory of Nanjing city will continue to escort cross river linkage and people's livelihood travel in a safer, smarter, and more comfortable manner, becoming a demonstration sample for urban rail transit renewal and renovation.Editor/BIan Wenjun