Concreting of the main beam of the Mulanxi cable-stayed bridge was completed Sunday, marking a major progress in the building of China's first cross-sea high-speed railway that links Fuzhou, capital of east China's Fujian Province, with the port city of Xiamen.

The bridge, spanning 18,747 meters along the Mulanxi River, is one of the most difficult parts of the railway construction project, which is slated for completion in 2023.

"The bridge construction has to take into consideration the safety of an expressway under the bridge and the adjacent Hangzhou-Shenzhen Railway," said Wang Chuanzong, a project leader with China Railway 16th Bureau Group Co., Ltd.

With a designed speed of 350 km per hour, the 277-km high-speed railway is expected to slash the travel time from Fuzhou to Xiamen to one hour.