Standing near a newly rotated continuous girder bridge traversing the Yiyang-Zhanjiang Railway, 25-year-old builder Deng Yelong was proud that the 14,000-metric-ton giant structure came into perfect position after a year of hard work.

The girder bridge, part of the Yulin-Cenxi section of the Nanning-Zhuhai High-Speed Railway, was built outside Yidong village in the Guangxi Zhuang autonomous region, and was successfully rotated on July 2 with a weight equivalent to about 9,300 automobiles.

"We started to build the swivel cast-in-place bridge on June 25, 2024," recalled Deng, a graduate from Jiangxi Science&Technology Normal University majoring in civil engineering and now a technical director at China Railway No 4 Engineering Group.

The 600-kilometer Nanning-Zhuhai HSR, linking Guangxi with neighboring Guangdong province with 15 stations, allows trains to run at a designed speed of 350 kilometers per hour.

Deng came to work at CREC4 Fifth Engineering upon graduation in 2023, and after one year working on digging tunnels and building railway beds on the No 3 bid of the HSR's Yulin-Cenxi section, he was promoted to technical director due to his outstanding work.

Pointing to the completed swivel railway bridge, he said: "Please look at the two giant parts spanning both sides of the pillar bridge-pier. Both extend for 80 meters each, and have to be cast alongside the existing railway without any effect on its operations. We worked with some 40 employees for one year on the job.

As a technical director, my burden was heavy, as the rotation project is a tough battle and the behemoths must be rotated 41 degrees at a height of 40 meters," adding that the precision must be controlled within millimeters.

"This cannot be achieved through individual heroism, but from teamwork," he said, recalling that even during the traditional Spring Festival for family reunions, they still worked on their job.

"As a builder, watching the project taking shape day-by-day, this sense of transforming a piece of land is unlike any other job."

Deng's quick promotion on the job showed that building railways is helping cultivate more skilled technicians and managerial staff.

Liu Di, 34, deputy chief-engineer of CREC4's prefabricated components smart center for the No 3 bid of Yulin-Cenxi section on Nanning-Zhuhai HSR, was happy to see more new technologies being adopted by CREC4 in building the new railways.

Liu said they saw the first introduction of an intelligent production line for the prefabrication of small components in August 2023, when construction of CREC4's center for the small components was completed, making it the country's largest and most advanced at the time. It began operations on Aug 13.

"The center is responsible for the prefabrication of precast concrete components for all five bids of the Yulin-Cenxi section, including 61,043 roadbed protective fences, 6,092 pile retaining plates, 443,802 hollow bricks, 24,204 cable troughs, 76,080 cable-trough covers, 390,344 bridge cover plates, 50,238 shutters and 438,377 tunnel cover pieces," he said.

"Our precast concrete component requires some 55,987 cubic meters of concrete, which can fill 22 Olympic-sized swimming pools (each measuring 50 meters in length, 25 meters in width, and 2 meters in depth, covering some 2,500 cubic meters), while our steel reinforcements are about 8,614 tons — equivalent to the weight of over 5,700 automobiles put together."