The construction of the Nanjing Yangtze Tunnel, which began in September 2005, has reached a water depth of 60 metres, a landmark for the world-class tunnel-building technology that China claims to have mastered

The 5,853-metre-long tunnel is the most challenging engineering project along the Yangtze. So far, 4,038 metres of the tunnel has been completed without any leakage or other technical problems.

There are more than 60 bridges across the Yangtze built or being built. But only two cities have tunnels across the Yangtze: one is in Shanghai and other Wuhan. The Nanjing tunnel, upon completion, will help alleviate traffic jams across the river in Nanjing.

The project is being built by a consortium headed by the China Railway Construction Corp on a BOT basis for 34 years: four years for construction and 30 years of operation and maintenance. The tunnel will have six lanes and a top speed of 80 kph. The total investment is Rmb3.3bn, less than a third of the cost of Nanjing No.4 Bridge.