The giant ship lock of the Three Gorges Water Control Project on the Yangtze River opened officially for navigation on Thursday following a one-year successful trial operation.

Construction of the two-way five-step lock, the largest in the world, took nine years as from April 17, at a cost of 6.2 billion yuan (746.99 million US dollars),

The ship lock, which features a two-way lifting facility for the 113-meter drop between the upstream and downstream separated by the gigantic dam, went into trial operation after the Three Gorges reservoir began to store water in June 2003.

The lock, which was built entirely by Chinese engineers after solving a number of unprecedented technical difficulties, enables ships to pass through the dam in about two and a half hours via the 6.44-km-long dock on the northern bank of the Yangtze River.

The construction of the Three Gorges Project, the world's biggest hydro-electric project, began in 1993 and is expected to be completed in 2009.

(Xinhua News Agency July 9, 2004)