Two record-breaking bridges in eastern China’s Zhejiang province are nearing completion simultaneously — one redefining cable-stayed bridge engineering, the other setting a new benchmark for high-speed railway construction directly over the open sea.
The Qinglongmen Grand Bridge has completed its main structure, according to China’s Science and Technology Daily, which reported that it would link a cluster of islands within the Ningbo-Zhoushan port complex. It is the world’s longest three-tower cable-stayed bridge, and its design breaks from conventional cable-stayed engineering in a way that has direct structural and logistical implications.
Three towers instead of two — Why it matters
Unlike conventional cable-stayed bridges that rely on two towers, the design uses a third pylon to support longer spans across wide shipping channels. The Qinglongmen bridge features twin main spans of 756 meters — spans only achievable because the third tower distributes cable loads that two towers alone could not handle without prohibitively thick decks or compressed span lengths.
Standing 249 meters tall — roughly the height of an 80-story building — its three towers form the centerpiece of a project to integrate previously fragmented port islands into a unified expressway network. The total bridge length is 2,212 meters (7,257 feet).
Built by two subsidiaries of China Railway Construction Corporation — China Railway Construction Bridge Engineering Bureau Group and China Railway Port Bureau Group — the bridge is part of a 17.6 billion yuan (US$2.6 billion) infrastructure program launched in 2022 to improve freight connectivity at the port.
The strategic purpose is straightforward. Ningbo-Zhoushan is the world’s busiest cargo port by tonnage, but the port complex spans a dispersed archipelago of islands that have historically required vessel transfers or long road detours to connect. The Qinglongmen bridge is the physical link that turns that fragmented island network into a single, truck-accessible expressway system.
The railway bridge that crosses the bay at 350 km/h
The second record is being set simultaneously in the same bay. The Hangzhou Bay Cross-Sea Railway Bridge — currently the world’s longest railway bridge built directly over the sea — is part of the Nantong–Suzhou–Jiaxing–Ningbo high-speed railway. Stretching 29.2 kilometers and designed for speeds of up to 350 km/h (~217mph), the bridge will allow high-speed trains to cross Hangzhou Bay in approximately 10 minutes once operational.
The bridge will significantly enhance connectivity and support high-quality, integrated development across the Yangtze River Delta, one of China’s most dynamic economic regions.
Its engineering profile includes three waterway channel bridges and approach spans crossing embankments, open sea, and tidal shallows. The main span of the north channel bridge is 450 meters — the world’s longest-span ballastless track cable-stayed bridge — and the main span of the middle channel bridge is 2×448 meters, the world’s longest-span three-tower cable-stayed bridge with ballastless track.
The completion of its first main tower on January 16, 2026, marked a significant milestone. Once completed in 2027, the bridge will stand as the longest high-speed railway bridge in the world. The construction environment is among the most demanding on Earth — Hangzhou Bay experiences some of the strongest tidal forces in the world, with complex geological conditions, ecological red line constraints to protect fish migration channels, and frequent typhoons.
Together, the two Zhejiang megaprojects represent the current frontier of bridge engineering: one pushing the limits of cable-stayed span geometry over a major shipping port, and the other proving that high-speed rail can be built at record length directly over open ocean — engineering benchmarks that will stand until China or another nation deliberately sets out to break them.