Offshore survey ends for cross-sea rail bridge By LUO WANGSHU | China Daily | Updated: 2021-04-15 09:43 Share CLOSE China has completed an offshore survey for a cross-sea high-speed railway bridge in Zhejiang province that will become the world's longest such bridge upon completion. The 29.2-kilometer Hangzhou Bay bridge, with a designed speed of 350 km per hour, will be part of the railway line linking Nantong in Jiangsu province and Ningbo in Zhejiang. It is unclear when construction will begin. The offshore survey that was completed on Monday took five months, two and a half months less than scheduled, said Zhang Peng, an engineer from China Railway Design Corporation, the bridge's designer.