Three Gorges shiplift resurfaces

By Other News Sources on November 7, 2003 • ( Leave a comment )

Kelly Haggart and Mu Lan

November 7, 2003

After almost half a century of study, a decision on the design of the world’s biggest shiplift at the biggest dam has been made, the Three Gorges Project Daily (Sanxia gongcheng bao) reports.

Construction of the Three Gorges shiplift, which will be the largest in the world both in terms of height and hoisting capacity, is scheduled to start in 2005 and be completed in 2009, the newspaper said.

The Three Gorges Project Construction Committee approved a rack and piston hoisting system of a type that has been in use for decades in large shiplifts abroad, particularly in Germany.

The mechanism will be able to lift vessels weighing up to 3,000 tonnes, raising them to the higher water level on the upstream side of the dam much more quickly than the five-stage shiplock that went into operation in June.

According to the Three Gorges Project Corp., it will take a vessel half an hour to be hoisted by the shiplift, but 2.5 hours to get through the shiplock. (In reality, passengers have found that the trip through the five locks takes about four hours.)

However, because of its sheer size, the Three Gorges shiplift is considered a challenge to design, manufacture and install. The Survey and Design Institute of the Changjiang Water Resources Commission (CWRC) is responsible for the overall design of the structure, including the hoisting mechanism. Some key components will be imported, the newspaper said, and foreign companies will be invited to submit designs for the ship-container part of the structure.

The CWRC first began studying the feasibility of the Three Gorges shiplift in 1958. An inspection team of engineers and government officials went abroad in 1983 to look at shiplifts in many countries, with a particular focus on Germany.

A final decision on the shiplift has been delayed for years. When the Three Gorges project was approved by the National People’s Congress in 1992, the CWRC recommended a hoisting system employing steel cables. More recently, a panel of experts chaired by Pan Jiazheng, a chief designer of the Three Gorges dam, was convened to choose which system to use. In the end they opted for the rack and piston mechanism, considered the safer, more tested technology.

However, not everyone thinks the correct decision has been made. One engineer with the Three Gorges Project Corp. says the system chosen is largely a copy of German technology that will be much more complicated and expensive to build than a design he himself submitted for the shiplift.