According to Chinese media including Science and Technology Daily, the south channel bridge's steel truss closed on the evening of the 17th, the first of three channel bridges to do so. The bridge is a key section of the new Nantong-Ningbo high-speed line (301 km, designed for 350 km/h), running from Haiyan in Jiaxing in the north to Cixi in Ningbo in the south.

The south channel bridge is a steel-truss cable-stayed bridge with a 364 m main span, built to let 3,000-tonne vessels pass. The truss weighs about 10,700 tonnes and was made in 58 segments at a factory, assembled into 10 large sections and shipped by water, then lifted at sea by the 2,200-tonne crane vessel Qinhanggong 1.

Building in strong tides

Hangzhou Bay is one of the world's three major strong-tide bays, with a maximum tidal range of nearly 9 m and currents up to 5.3 m per second. The reports say winds of force 6 or higher blow about 180 days a year and fewer than 200 days are usable for offshore work. The closure used a two-sided jacking method, with BeiDou positioning and digital monitoring said to hold deviation to the millimeter level, and it was carried out at night when temperatures were steadier.

Science and Technology Daily said the closure lays the groundwork for later cable tensioning and deck ancillary works. On September 3, the three main towers of the middle channel bridge were completed on the same day, moving that span into truss erection. No opening date appears in the sources we verified; the Chinese side says the finished line will link Nantong and Ningbo in about an hour. That figure and the ‘world's longest’ label rest on Chinese media and the builders' own descriptions.