In this video diary, the ongoing critical path activity is the installation of PPWS: 144 are being placed in the main span and 148 in the side spans.
Each span is made up of 127 wires with a 5.7mm diameter. Once completed, including the wrapping wire, the main cable will have a designed compacted diameter of 888mm in the side span and 876mm in the main span.
The longest continous PPWS are nearly 4,370m, and after main cable installation is finished, cable bands and hanger installation will be performed before proceeding to the lifting and installation of the main deck blocks.
As on the towers, the main cables will be installed with a dehumidification system. Floowing completion of compaction and wrapping works, along the length of each of the two main cables will be installed 11 dry air injection sleeves and 12 exhaust ports.
The typical spacing between inlets and outlets will be 200m. The dry air, processed at deck level, will travel through pipes installed around selected hangers, then along the main cables, carrying with it any eventual moisture or humidity and maintaining the wire strands in a corrosion-free environment.
To protect the wrapping wire and wrapping bands against eventual bulging, injection pressure is kept to a maximum 2,500Pa.