It was learned on August 24 that the Longquanshan Tunnel on the Chengdu-Chongqing Middle Line Railway has fully entered the main tunnel construction stage. This marks a major breakthrough in the tunnel's construction and provides favorable conditions for subsequent work.

As a key section of the entire Chengdu-Chongqing Middle Line Railway, the Longquanshan Tunnel has a total length of 8,027 m and is a single-tube, double-track tunnel with a maximum buried depth of 220 m. The entire tunnel is a gas tunnel. According to reports, the tunnel has two inclined shafts, and the main tunnel construction is divided into four work sites and six working faces: the entrance, No. 1 inclined shaft, No. 2 inclined shaft, and the exit. With the last working face entering main tunnel construction, the schedule is one week ahead of the predetermined milestone.

The newly built Chengdu-Chongqing Middle Line Railway has a total length of 291 km. It starts from Chongqing North Station, passes through Chongqing Municipality, Ziyang City in Sichuan Province, and Chengdu City, and ends at Chengdu Station. The line has 8 stations in total and is designed for a speed of 350 km/h. Construction began on November 28, 2022. As a landmark project in the construction of the Chengdu-Chongqing Twin-City Economic Circle, the newly built Chengdu-Chongqing Middle Line has been listed as a national key railway project of the 14th Five-Year Plan and is an important component of the national "Eight Vertical and Eight Horizontal" Shanghai-Chongqing-Chengdu high-speed railway corridor along the Yangtze River. Once completed, it will enable 50-minute connectivity between the two core cities of Chengdu and Chongqing and promote leapfrog economic development in the western region.