As the last batch of concrete was slowly poured from the delivery pump truck into the formwork, the No. 5 main tower of the Xihoumen Road-Rail Dual-Purpose Bridge of the Ningbo-Zhoushan Railway was capped. The bridge is managed for construction by Shanghai Guotie Construction Management Co., Ltd., with investment led by China Railway Shanghai Investment Co., Ltd., design by China Railway Major Bridge Reconnaissance & Design Institute Co., Ltd., and construction by China Railway Major Bridge Engineering Group Co., Ltd. This is also the first bridge main tower to be capped along the entire Ningbo-Zhoushan Railway line. The 294-meter-high main tower sets a new world record for the height of a sea-crossing bridge main tower.

The bridge has two main towers, No. 4 and No. 5, each 294 meters tall (including the tower base), making them the world's tallest sea-crossing bridge towers. The No. 5 main tower shaft uses C60 concrete and is divided into 50 construction segments, including 8 for the lower column, 22 for the middle column, and 20 for the upper column.

The foundation of the No. 5 main tower pier adopts 18 large-diameter bored cast-in-place piles with a diameter of 6.3 meters. The 6.3-meter-diameter bored pile is currently the largest-diameter bridge bored pile foundation in the world. To this end, the project team planned ahead and conducted two pile foundation tests, on land and on water, verifying and improving a full set of new techniques, including synchronous underwater concrete pouring for pile foundations with dual tremie pipes, electric wrench tightening of large-diameter rebar joints, and quality inspection of super-large-diameter pile foundations using inner and outer layers of sonic logging tubes.

The Xihoumen Road-Rail Dual-Purpose Bridge is a shared sea-crossing bridge carrying both the Ningbo-Zhoushan Railway and the Ningbo-Zhoushan Expressway duplicate line across the Xihoumen waterway, connecting Jintang Island and Cezi Island in Zhoushan. It is a key controlling project of the entire line. The bridge has a total length of 3,118 meters and adopts a cable-stayed-suspension cooperative structural system with a main span of 1,488 meters, making it the world's largest-span road-rail dual-purpose bridge, the world's largest-span cable-stayed-suspension cooperative system bridge, and the world's widest sea-crossing bridge.

The main tower of the bridge adopts an "A"-shaped reinforced concrete structure, designed to be wide at the bottom and narrow at the top to form a stable triangular support system. This geometric structure can effectively distribute bridge deck loads and enhance wind and seismic resistance, making it especially suitable for strong-wind environments such as sea-crossing bridges, with features including strong stability, rational force distribution, and high spatial efficiency.The project applied a number of advanced intelligent construction methods from China Railway Major Bridge Science Research Institute Co., Ltd., including intelligent climbing formwork and automatic measuring robots. Temperature and humidity sensors precisely "monitor" concrete curing, intelligently adjusting the curing environment and enabling real-time online monitoring of the main tower's alignment.