On February 24, 2021, beneath the calm waters of Qianhai Bay, the Mawan Cross-Sea Passage connecting Bao'an and Qianhai is under rapid construction. A super-large-diameter slurry pressure balance shield machine with a diameter of 15.53 meters is about to launch, tunneling through complex subsea terrain to open Shenzhen's first cross-sea tunnel and create China's largest cross-section cross-sea shield tunnel. The reporter learned from the Municipal Transport Bureau that the open-cut tunnel of the Mawan Cross-Sea Passage is advancing rapidly, the shield launching shafts at both ends are nearing completion, and the shield machine is being delivered to Shenzhen for assembly. Tunneling is expected to officially begin in the first half of this year.

The Mawan Cross-Sea Passage project starts at the intersection of Mawan Avenue and Yueliangwan Avenue in the Mawan Port Area of Qianhai and ends at the Dachan Bay Toll Station of the Yanjiang Expressway and the intersection of Jinwan Avenue and Xixiang Avenue in the Dachan Bay area of Bao'an, with a total length of 8.05 kilometers. The Mawan Cross-Sea Passage consists of two parts: surface roads and underground roads. The underground road is planned as an urban expressway with six lanes in both directions and a design speed of 80 kilometers per hour. The tunnel has a total length of 6.28 kilometers, including 0.82 kilometers of open-cut tunnel in the Qianhai land area, 2.06 kilometers of shield tunnel in the sea section, and 3.4 kilometers of open-cut tunnel in the Dachan Bay land area. The surface road is planned as an urban arterial road with six lanes in both directions and a design speed of 40 kilometers per hour, including 2.3 kilometers of surface road in Qianhai and 4.4 kilometers of surface road in Dachan Bay.

Driving from Qianhai onto the Yanjiang Expressway, exiting at the Xixiang South Toll Station, and turning south onto Jingang Avenue, one can see the construction fencing of the Mawan Cross-Sea Passage. This is Section 2 of the Mawan Cross-Sea Passage project. Led by China Railway, the consortium of China Railway / China Railway Tunnel Group / China Railway Seventh Group, a leader in large-diameter shield construction in China, is responsible for the construction of this section. At the southernmost end of Jingang Avenue, the shield launching shaft of Section 2 of the Mawan Cross-Sea Passage has begun to take shape, and more than 80 builders are tying rebar on scaffolding. Ma Hongjian, project manager of the Mawan Cross-Sea Passage for China Railway Tunnel Group, told the reporter: "This shield launching shaft is 55 meters wide, 25 meters long and 29.5 meters deep. Foundation pit excavation has been completed and rebar is being tied. Concrete will be poured next. It is expected to be ready for shield machine launch in the first half of this year."

Looking out from Jingang Avenue across the rippling sea, Qianhai is close at hand. In the future, a 15.53-meter super-large-diameter slurry shield will tunnel beneath the seabed, creating the most convenient subsea passage between Bao'an and Qianhai. The Mawan Cross-Sea Passage is Shenzhen's first subsea tunnel and currently China's largest cross-sea shield tunnel. Shen Haiyang, an engineer at the Construction Center of the Municipal Transport Bureau, told the reporter: "After the Mawan Cross-Sea Passage is completed, it will optimize the port traffic organization of the western port area, divert container trucks from Shekou Port, Chiwan Port, Mawan Port and Dachan Bay Port directly onto the Yanjiang Expressway via the Mawan Cross-Sea Passage, greatly reducing surface traffic pressure in Bao'an and Qianhai, achieving the separation of passenger and freight traffic in the western road network, and strengthening the connection between Qianhai and urban districts such as Bao'an, Nanshan and Futian."

During this year's Spring Festival holiday, construction of the Mawan Cross-Sea Passage project did not stop. More than 900 builders stayed in Shenzhen for the holiday and remained at their posts. At present, all participating personnel have returned to work. While carrying out epidemic prevention and control, the project department is arranging construction reasonably, advancing the project in an orderly manner, and striving to officially launch the shield machine underground in the first half of this year.