As revealed in NCE in January, the Highways Agency will start to install a dehumidification system to dry the corroded cables on the M48 Severn Bridge (see NCE 01/05/2007)
The work will begin over the weekend of June 16 and 17, and continue throughout the summer. The cables will be wrapped in an impermeable material and dry air will be blown through the small spaces between the wires inside the cables. Drying the cables should reduce the rate of deterioration.The system will be installed on the middle section of both cables, where inspections revealed that the worst corrosion has occurred.Acoustic monitoring equipment will be installed on the full length of the cables to give a live picture of the state of the cables.Closures will take place throughout the summer, and work can only be undertaken during daylight hours and in reasonable weather conditions. Assuming conditions are good, work will take place between 6am and 9pm over weekends.