A main cable with a diameter of over 1 meter is erected directly above the middle of the catwalk of the Lingdingyang Bridge, the highest sea-based catwalk around the world, connecting the east and west main towers. The right main cable of the Lingdingyang Bridge was erected on September 10, and it is currently being tightened.

The Lingdingyang Bridge section of the Shenzhen-Zhongshan Bridge is a suspension bridge with a main span of 1,666 meters and a main tower height of 270 meters. It is the largest-spanning steel-box-girder suspension bridge in the world at present. There are two main cables on the upstream and downstream sides of the Lingdingyang Bridge. Each main cable consists of 199 strands, for a total of 398 main cable strands. Each strand is about 3,000 meters long and weighs about 85 tons. It consists of 127 zinc-aluminum alloy coated high-strength steel wires with a diameter of 6 mm. 

The main cables are the most critical stress component of Lingdingyang Bridge and is often called the "lifeline" of a suspension bridge. After completion, the maximum force on the two main cables will be more than 100,000 tons, which is equivalent to the weight of three medium-sized aircraft carriers.