The Chengdu-Chongqing Middle Line High-speed Railway, a major transportation link in Southwest China, saw the successful completion of its full box girder erection work on Tuesday, as the final 32-meter-long box girder, weighing about 700 tons, was steadily installed onto the piers of the Jialing River Grand Bridge. This step lays a solid foundation for the project's early opening and operation, the People's Daily reported.

The construction of the line reflects the improvement of infrastructure and engineering capabilities in China's central and western regions, a Chinese industry analyst said, noting that it is expected to strengthen regional connectivity, promote the integration of tourism and economic development, and further enhance the level of openness and the urban radiating capacity of inland areas.

The Chengdu-Chongqing Middle Line High-speed Railway line starts from Chongqing North Railway Station, runs westward through multiple areas including the Liangjiang New Area, Shapingba district, Dazu district, and city of Ziyang in Sichuan Province, and connects to Chengdu Station. The main line has a total length of 292 kilometers, with a designed speed of 350 kilometers per hour, and certain sections have provisions for speed upgrades.

Box girders are the key load-bearing components of a bridge, carrying all loads from the bridge deck and forming the stable main support structure of the high-speed railway bridge once ballastless track construction and track laying are completed, the report said, citing Wang Gang, a manager for the Chengdu-Chongqing Middle Line High-speed Railway project at the China Railway 12th Bureau Group.

All substructure work along the entire line has been completed, and the project has fully entered the critical phase of ballastless track construction, while station buildings and supporting systems, including power and signaling, are being advanced efficiently and in an orderly manner, according to the report.

The Chengdu-Chongqing Middle Line High-speed Railway is an important part of China's "eight vertical lines and eight horizontal lines," specifically along the Yangtze River corridor.

According to national plans, China's high-speed rail network will reach 70,000 kilometers by 2035, comprising eight main vertical lines linking the north and south and eight horizontal lines connecting the east and west. Once completed, the network will cover major cities, city clusters, and key economic zones nationwide.

This high-speed railway serves as a fast corridor linking Chongqing and Chengdu, supporting the Chengdu-Chongqing economic circle and playing a key regional hub role, Sun Zhang, a railway expert at Shanghai's Tongji University, told the Global Times on Tuesday. From an engineering perspective, it is difficult to build due to complex terrain and a high proportion of bridges and tunnels, placing high demands on construction organization and technical capability, and reflecting strong capacity in major infrastructure development, the expert said.

Economically, the line will not only shorten travel times among core cities, but also improve efficiency in industrial coordination, resource allocation, and regional economic integration, facilitating smoother flows of people, capital, information, and talent, and enhancing overall regional synergy, said Sun.

Sun said that with Chongqing and Chengdu both rich in tourism resources, better access will help strengthen tourism integration, increase their attractiveness to domestic and international visitors, and promote the integrated development of regional tourism.