All seven main towers of the Hangzhou Bay Cross-Sea Railway Bridge were topped out in Jiaxing, east China's Zhejiang, on September 3, marking a major milestone for the world's longest high-speed rail bridge over the sea. 

The bridge uses factory prefabrication and integrated assembly to withstand challenging tidal and high-humidity conditions. With construction now moving to the upper structure, the 350 km/h high-speed rail line will transform travel across the Yangtze River Delta.