Construction of the Xihoumen Highway and Railway Bridge in East China's Zhejiang province reached a milestone on Tuesday with the successful installation of its first steel beam, signifying its transition to the main tower superstructure construction phase, Science and Technology Daily reported.

With a width of 68 meters, the bridge is set to be the widest dual-use bridge for both road and railway traffic in the world.

As part of the Ningbo-Zhoushan Railway, the bridge across the Xihoumen waterway has a main span of 1,488 meters and a total length of 3,118 meters, connecting two islands in Zhoushan city.

To combat the frequent impacts of typhoon, the bridge adopts a pioneering "rail-road combined deck" design and employs three separated steel box girders, interconnected in a ladder-like configuration, to enhance wind resistance.

"This structure, coupled with dual-track rail and six-lane highway requirements, creates the world's widest bridge deck at 68 meters," said Xiao Haizhu, chief engineer of China Railway Major Bridge Reconnaissance and Design Institute.

According to the report, the complexity of installation due to varying support systems across cable-stayed and suspension sections, requires three distinct plans to carry out the steel beam erection, with works expected to finish by 2027.

Upon completion, the bridge will allow trains to travel up to 250 kilometers per hour, linking Zhoushan, Zhejiang's last city which is not connected by rail.