Hong Kong side catches up with completed wind cowl

Civil engineering was finalized on the main part of the Islands-Tunnel Section of the Hong Kong-Zhuhai-Macao Bridge (HZMB) on Oct 18, with a wind cowl now in place atop each of two engineered islands.

The latest step was to cover Eastern Artificial Island -- one of the key structures connecting a sub-sea tunnel spanning the Lingding Sea -- only five days after similar work ended on Western Artificial Island. The eastern facility is adjacent to Hong Kong while the western island accesses Zhuhai and Macao.

The milky white wind cowls, each consisting of a tower surmounted by a radar station, weigh 210 tons each and are 17 m tall and 35 x 32 m in dimension. Erect in an aesthetic way, the wind cowls have special air outlets to ventilate the immersed tunnel section, according to Zhang Zhigang, a project head.

These tallest island buildings on the two islands were installed with structural steel frames to ensure holding power and fair-faced concrete finishes.

Wind cowl on Eastern Artificial Island

Immense and unusual difficulties arose from the three-dimensional spatial elements required for the cowl structures. Solutions included ring box girders, H-shaped steel beams, steel columns, and round tube beams.

Components are complicated and were needed in large number, said Lin Ming, general manager of the Tunnel-Bridge Project Department. Lin added that despite complications, the arduous mission was accomplished with high accuracy and within a tight schedule, not to mention the tough working environment in open waters.

Lin predicted that the two man-made islands will emerge as landmarks on the Pearl River Estuary in the near future.

Finished main body of Western Artificial Island [Photos by Chen Xinnian / Zhuhai Daily]