It may not be as picturesque as the soaring Tsing Ma Bridge but the man in charge of building the Western Harbour Crossing tunnel, opened yesterday, believes it is an even more impressive engineering achievement.
Two kilometres long, 1,300 metres of that length under the sea, the tunnel runs from the tip of sandy Western Kowloon Reclamation to Sai Ying Pun, on Hong Kong Island, where a complex new road junction to disperse tunnel traffic is crammed on a narrow site between high-rise buildings and the harbour.
'This is one of the largest immersed-tube tunnels in Southeast Asia, so it was no mean feat,' project manager John Mundy said proudly, in his dusty office in a prefabricated building near the gaping West Kowloon portal.
The figures are mind-boggling: more than 12 million man-hours to turn 470,000 cubic metres of concrete and 84,000 tonnes of reinforcing steel into a tunnel. The airport core project can handle 180,000 cars each day, directed to more than 10 kilometres of approach roads and 17 bridges by more than 300 road signs across the territory. Construction accidents cost four workers their lives.
As an immersed tube tunnel, the Western Harbour Crossing runs through a giant concrete pipe buried just under the seabed rather than through a hole bored deep in the bedrock.
Crowded Hong Kong is ideal for this technique because it does not take up much space. Now five of the world's 100 immersed-tube tunnels are located in the territory, says Mr Mundy, including Eastern Harbour Crossing. 'You choose to go for an immersed tube because you can keep the tunnel shallow, and therefore that reduces the lengthy approaches,' he explains.