Yichang City, Hubei Province, central China - Sept 18, 2016
1. Ship elevator
2. Various of ship taking elevator
3. Various of elevator going upwards
4. Various of ship getting out of elevator
5. Various of ship going downwards
6. Various of head bay
7. Ship on Yangtze River

The world's largest ship elevator at the Three Gorges Dam opened in Yichang City, central China's Hubei Province, on Sunday, with a prospect to increase the shipping capacity past the dam by six million tons a year.

The elevator, the existing largest lifting structure on a navigation route with the highest technical difficulty of the world, features large engineering scope, high lifting height and large weight lifting operation.

The largest weight to be handled by the elevator is freighter of 3,000 DWT(deadweight ton) and the maximum vertical lifting height is 113 meters.

The main components of the structure are four 169-meter high reinforced concrete towers. The chamber, a self-support orthotropic plate structure that is 120 meters long and 18 meters wide, works as a gigantic basin.

Weighting around 15,500 tons, the elevator carries the ships upwards or downwards to pass the dam.

A special safety mechanism, or a brake pad, is fixed. Four short screw sections connected to the ship chamber work as rotary locking rods.

They rotary locking rods work continuously in an internal thread, or a nut post, that is fixed to the towers. If an accident occurs, this rotation is blocked and traction is achieved that supports the ship chamber independently.

The elevator will cut journey times for passenger, cruise and small cargo ships passing through the dam from over three hours to about 40 minutes.

Larger vessels still have to pass the dam by means of a two-lane, five-chamber lock chain like climbing stairs. "Large vessels walk the stairs, small ones take the elevator" to pass the Three Gorges Dam for some time to come.

The elevator marks the completion of the Three Gorges Dam project on the Yangtze River, which aims at producing electricity, increasing the Yangtze River's shipping capacity and reducing the potential for floods downstream by providing flood storage space.