Amazing engineering: the Sidu River Bridge, China

       The Sidu River Bridge (Siduhe Bridge, 四渡河特大桥) is a 1,222 m-long (4,009 ft) suspension bridge crossing the valley of the Sidu River near Yesanguan in Badong County of the Hubei Province of the People's Republic of China. 

The bridge was designed by CCSHCC Second Highway Consultants Company, Ltd. and built at a cost of 720 million yuan (approximately US$100 million). It opened to traffic on November 15, 2009.

The bridge's design includes H-shaped towers, a truss-stiffened main span, and unsuspended side spans. The Warren-type trusses were constructed in seventy one sections with the largest section weighing 91.6 metric tons (101.0 short tons). The trusses are 6.5 m (21 ft) tall and 26 meters (85 ft) wide.

 The height measurement from the bottom of the gorge has been reported as 496 m by Eric Sakowski, 500 m by Chongxu Wang, and 550 m by Yinbo Liu.The first part of the suspension cable installed, a rope known as the pilot cable, was the first-ever to be placed using a rocket. Conditions at the bridge's location would not allow the use of boats or helicopters, which have previously been used to string the first cable. The rockets carried the pilot cables across on October 6, 2006 and resulted in time and cost savings.The main suspension cable are made of 127 parallel wire strands bundled into a hexagonal shape. Each strand is made of 127 wires (also making a hexagonal shape so that there is a total of 16,129 wires in each of the two main suspension cables. Each cable can hold 191,960 kilonewtons (43,150,000 lb_f).