Operating Principle of Yangtze Cruise passing through Three Gorge FIve-Step Ship Locks
As the dam that has the largest steps in the world, the Three Gorges dam is a five-step ship lock. It’s a hydroelectric dam located in Yiling District, Yichang, Hubei Province. It is 6.4 kilometers in length, wherein the lock body part is 1.6 kilometers, approach channel is 4.8 kilometers. The Permanent Ship Lock consists of 24 Miter Gate, among which 18 miter gates are 38.5 meters high, and each width is 20 meters, thickness is 3 meters , weight is 850 tons, their area is nearly as large as two basketball fields. Its shape and weight are the best and heaviest in the world.
The water level difference is the biggest in most of the world. In front of the Three Gorges Dam, normal water level is 175 meters above sea level, while the lowest water level for dam navigation is 62 meters, which means that the fall between upper ship lock and the down ship lock is 113 meters, and ships need to climb over a 40-storey building.
How do ships go upstream or downstream? Here is a simple interpretation. When a ship is coming from Downstream, it needs to go on the dam, and then operator will have the water level of the fifth lock chamber same with the water level of downstream, and open the gate, the ship enters the chamber; the tail gate is closed, the water system fills the chamber with water, thus the ship will rise up as the water level rises up. When the water level is same with the water level of the fourth chamber, operator opens the first miter gate of the fifth ship lock. The ship is like climbing a stair, and goes into the next lock chamber easily. The ship goes up like this, until it reaches the first chamber, and then enters Pinghu Gorge. If the ship goes down from the upstream, the process is just the opposite. The design of permanent ship lock is very scientific. There are two roads, one is for uplink, the other is for downlink, so there will be no interference between them, and it’s also time-saving. It takes almost 4 hours to go upstream or downstream.
Watching ships going through Three Gorge Dam becomes a rare view because of the unique structure of the dam. There are tourists taking Yangtze cruise to witness the magnificent scenery, and it’s getting more and more popular.