Cross Bay Bridge tunnel only steps toward completion

The world's longest subsea tunnel -- 6.7-km and nearly 30 m deep in the Lingding Sea -- is now fully intact and just needing final touches. The closure joint was welded with the E29 and E30 immersed tubes on May 25. After other milestone accomplishments, this is said to mark completion of the subsea eternal structure of the Hong Kong-Zhuhai-Macao Bridge.

The feat is a key part of completion. More than 200 workers had spent three months drilling before the operation began on May 5. Before it could proceed, installation and precise adjustments of the final joint had to be made. The following 20 days and nights were tense as construction advanced from welding preparation to the assembly and jointing of the cavity baffle plates. 

Works connect tunnel tubes [Photo by Zhong Fan/ Zhuhai Daily]

The team carrying out the final welding tasks consisted of 258 members, who overcame extraordinary difficulties such as the narrow, sweltering, and closed environment, stale air, heavy steel structure, and tight time limits.

Working in three shifts, they labored for 478 hours straight. In that period, the welding of over approximately 2,300 m was completed, consuming 20 tons of materials and over 2,000 bottles of gas. All the welded have since been certified by inspection.

According to Yin Haiqin, vice general manager of the project's General Manager Department, workers will now carry out joint grouting and shield removal. The world's longest subsea tunnel will then finally be completed in a short time.