A staff member watches over the installation of the first box girder of Dazu section of the middle line of Chengdu-Chongqing railway at the construction site in Dazu District of southwest China's Chongqing Municipality, May 16, 2025. The first box girder weighting 697 tonnes at a length of 32.6 meters was accurately set up on Friday.

Upon completion, the 292-km middle line of the Chengdu-Chongqing railway will allow trains to run at a top speed of 350 km/h on it, and is expected to reduce a trip between the two cities to merely 50 minutes. (Xinhua/Chen Cheng)

An aerial drone photo taken on May 16, 2025 shows a scene during the installation of the first box girder in a super major bridge of Dazu section of the middle line of Chengdu-Chongqing railway in southwest China's Chongqing Municipality. The first box girder weighting 697 tonnes at a length of 32.6 meters was accurately set up on Friday.

Upon completion, the 292-km middle line of the Chengdu-Chongqing railway will allow trains to run at a top speed of 350 km/h on it, and is expected to reduce a trip between the two cities to merely 50 minutes. (Xinhua/Chen Cheng)

A staff member watches over the installation of the first box girder of Dazu section of the middle line of Chengdu-Chongqing railway at the construction site in Dazu District of southwest China's Chongqing Municipality, May 16, 2025. The first box girder weighting 697 tonnes at a length of 32.6 meters was accurately set up on Friday.

Upon completion, the 292-km middle line of the Chengdu-Chongqing railway will allow trains to run at a top speed of 350 km/h on it, and is expected to reduce a trip between the two cities to merely 50 minutes. (Xinhua/Chen Cheng)

An aerial drone photo taken on May 16, 2025 shows a scene during the installation of the first box girder in a super major bridge of Dazu section of the middle line of Chengdu-Chongqing railway in southwest China's Chongqing Municipality. The first box girder weighting 697 tonnes at a length of 32.6 meters was accurately set up on Friday.

Upon completion, the 292-km middle line of the Chengdu-Chongqing railway will allow trains to run at a top speed of 350 km/h on it, and is expected to reduce a trip between the two cities to merely 50 minutes. (Xinhua/Chen Cheng)

Staff members work during the installation of the first box girder in a super major bridge of Dazu section of the middle line of Chengdu-Chongqing railway in Dazu District of southwest China's Chongqing Municipality, May 16, 2025. The first box girder weighting 697 tonnes at a length of 32.6 meters was accurately set up on Friday.

Upon completion, the 292-km middle line of the Chengdu-Chongqing railway will allow trains to run at a top speed of 350 km/h on it, and is expected to reduce a trip between the two cities to merely 50 minutes. (Xinhua/Chen Cheng)

A staff member works during the installation of the first box girder in a super major bridge of Dazu section of the middle line of Chengdu-Chongqing railway in Dazu District of southwest China's Chongqing Municipality, May 16, 2025. The first box girder weighting 697 tonnes at a length of 32.6 meters was accurately set up on Friday.

Upon completion, the 292-km middle line of the Chengdu-Chongqing railway will allow trains to run at a top speed of 350 km/h on it, and is expected to reduce a trip between the two cities to merely 50 minutes. (Xinhua/Chen Cheng)