There were high fives galore in Shanghai on Sunday when the massive shield digging the Xizang Road S. Tunnel broke through to the Huangpu River's west bank.

Officials of the Shanghai No. 2 Engineering Co said the twin-passage tunnel would connect the two sides of the river and be open in time for the 2010 World Expo to be held in the city.

The eastern passage of the tunnel was the first to break through to the west bank, or Puxi side, of the river, engineers said yesterday.

The 2.67-kilometer tunnel will run under the river from the junction of Xizang Road S. and Zhongshan Road S. in Puxi to Pudong Road S. and Gaoke Road W. in Pudong.

Construction of the two 11.58-meter wide tunnels is due to be completed next September, but the tunnels will be dug by next month.

Engineers said yesterday there was just 150 meters left in the second tunnel.

The company made its own shield to dig the eastward tunnel - the largest so far built in China - while a shield was imported from Japan to dig the westward passage.

The company first imported the giant shield from Japan to penetrate under the river for the west passage and learned from that experience to invent its own tool to dig the east passage.

"At the closest point, the tunnel is only 2.68 meters below Metro Line 8 in Pudong," said project manager Chen Yong. "That's one of the several rare challenges we have conquered."

About 60,000 to 70,000 vehicles are expected to use the tunnel every day during 2010 World Expo. After the Expo ends in October that year, the tunnel will be open to ordinary traffic.

The Xizang Road S. Tunnel will connect the Expo zone on both sides of the Huangpu.

(Shanghai Daily July 21, 2008)