On January 5, new progress was made in the construction of the Tianshui–Longnan Railway. The Xinmaijishan Tunnel, undertaken by the No. 3 Sub-section of Section I of the Tianshui–Longnan Railway under China Railway No. 3 Engineering Group, achieved a major breakthrough: as two major control works, the No. 3 and No. 4 inclined shafts of the Xinmaijishan Tunnel both surpassed 2,000 meters in excavation, completing 76.78% and 77.88% of the construction tasks at their respective work points, marking a phased achievement in tunnel construction.

The Xinmaijishan Tunnel of the Tianshui–Longnan Railway has a total length of 19,818 meters. Its entrance is located on a gentle slope on the north side of Hujiagou, Ganquan Town, Maiji District, and its exit is located on a gentle slope on the north side of Lizi Village, Niangniangba Town, Qinzhou District. It is a single-tube, single-track tunnel with a maximum burial depth of about 747 meters and a minimum burial depth of about 12 meters. The tunnel project is constructed by three sub-sections, of which the main tunnel has a total length of 10,466.86 meters, accounting for 52.82% of the total length of the Xinmaijishan Tunnel. The No. 3 inclined shaft, whose excavation has now surpassed 2,000 meters, is 2,605 meters long, and the No. 4 inclined shaft is 2,568 meters long.

According to reports, compared with July 2023, when the No. 3 and No. 4 inclined shafts surpassed 1,000 meters after 10 months and 9 months respectively, this time the No. 3 and No. 4 inclined shafts advanced another 1,000 meters in less than 5 months. Compared with the previous stage of construction, the completion of this key milestone involved more difficulties than the last. As the excavation depth increased, the construction party overcame a series of unfavorable factors during construction, including increased water inflow at the tunnel face, greater ventilation difficulty, longer mucking cycle times, more difficult concrete transport, and variable surrounding rock geology.

In order to speed up construction progress, improve efficiency indicators, and advance the Tianshui–Longnan project with high quality and high efficiency, the construction party has continuously summarized experience, strengthened the analysis and control of advanced geological forecasting and toxic and harmful gas detection data, ensured construction safety inside the tunnel, and strictly implemented the "one blast, one plan" management system to improve blasting results, reduce potential safety risks in tunnel construction, and achieve the goal of improving work efficiency.

At the same time, the construction party strictly required the supervision site to carry out construction in accordance with approved special plans, designs, and specifications, strictly controlled construction quality, and accelerated construction progress while ensuring construction safety. A "coordination meeting" is held every day to analyze the daily work processes, summarize the problems arising between process transitions and during each process, ensure smooth transitions in each cyclic operation, shorten the single-cycle time, and ensure that the Xinmaijishan Tunnel is completed and opened to traffic as early as possible.