Three Gorges Dam Five-Step Ship Lock

The Three Gorges Dam project was completed in 2009, bringing dreams to fruition for Chinese leaders from as early as the 1920s who wished to harness the power of the Yangtze River. While the Three Gorges Dam was a feat of engineering all on its own, the freight capacity of the Yangtze River increased sixfold while shipping costs dropped 25 percent through the construction of the dam’s five-step ship locks.

Due to the construction of the dam, ships must be lifted or lowered over 300 feet (91.4 meters). Because of this height, the water pressure required for a single lock would be too much for one gate to withstand. Instead, the dam uses five locks, each raising or lowering the vessel about 65 feet (19.8 meters).

The two sets of staircase locks, one moving downstream and the other upstream, each consist of five stages and each can handle vessels weighing up to 10,000 tons. Passengers on Yangtze River excursions starting from or terminating in Yichang have the opportunity to pass through the locks with a transit time of two to three hours.