Shanghai’s container cargo handling capacity will double to 30 million boxes by 2010, after yesterday’s opening of the $16 billion Yangshan deep-water port, dislodging Hong Kong as the world’s busiest harbor.

Yangshan, a reclaimed island the size of 470 soccer fields in the East Sea, is designed to accommodate the world’s largest container ships at half the mooring charges, handle 15 million 20-foot boxes by 2010, and compete with Hong Kong and South Korea’s Busan as northern Asia’s main transshipment harbor.

The port is the showpiece of a $50 billion public spending spree to build ports to ship more toys, textiles, appliances, and furniture to Asia, North America, and Europe. China’s 11-month exports surged almost 30% from last year to $686.6 billion, while imports rose 17% to $595.7 billion, according to figures reported on Saturday.

“Yangshan is needed to cater for the large increase in container volume to and from Shanghai,” the Asia-Pacific transportation chief for International Business Machines in Shanghai, Henrik Anker Olesen, said. “If volume continues growing at last year’s 29% pace, Shanghai could overtake Hong Kong as the world’s largest container port by 2007.”

The opening of the Yangshan port, first proposed in 1918, will ease congestion in a harbor that has handled one of every four containers in Asia’s second largest economy. About 80% of global trade is carried by sea.