The Chongqing Rail Transit is the rapid transit system in the city of Chongqing, China. In operation since 2005, it serves the transportation needs of the city's main business and entertainment downtown areas and inner suburbs.
The extreme difference in elevation between the river valleys and the hilly plateaus of Chongqing poses a unique challenge in designing alignments for conventional rail transit lines. The network currently has the world's highest metro-only bridge, the Caijia Rail Transit Bridge for Line 6, spanning the Jialing River valley, with the bridge deck being approximately 100 m above the water.
Carrying two mass transit rail tracks, the signature bridge has a 640-meter-long main section that consists of five spans (60 meters, 135 meters, 250 meters, 135 meters, and 60 meters). The southern end section comprises two 45-meter-long spans, while the northern end section has six spans of 60 meters and three spans of 50 meters.
The bridge design successfully met stringent functionality requirements and aesthetic demands made by the project owners and the city of Chongqing.
The Chongqing Rail Transit is also in the process of constructing a number of extremely-long metro-only suspension bridges. The 1,650-meter long Egongyan Rail Transit Bridge carries the southern arc of the Loop line across the Yangtze River using a 600 m long suspension main span, making it the longest metro-only suspension bridge by main span in the world.
According to the Internet