Challenge
The main suspension cables and anchorages of the Chesapeake Bay Bridge were corroding due to water infiltration and humidity. The Maryland Transportation Authority, responsible for the bridge’s maintenance, needed a way to halt corrosion and extend the bridge’s working life. The busy bridge would need to remain in service while repairs were undertaken.
Solution
WSP teamed up with AECOM to design an innovative main cable dehumidification system for the dual main spans of the 4.3 mile bridges. The system was installed by the contractor team of Kiewit Infrastructure, HNTB and T.Y. Lin.
The first of its kind in North America, the project brought cable dehumidification systems proven effective in Europe and Japan to the U.S. and featured:
- Rewrapping and dehumidification of the main cables and anchorages of the bridge’s eastbound and westbound main spans.
- A system of plant rooms that pipe dry air into cables through injection sleeves while exhaust sleeves along the cables remove moisture-laden air.
- Strategic lane closure to reduce impact to travelers during project implementation.
- Extensive shop trials to provide training and mastering of the techniques of main cable wrapping, band caulking and testing air injection and exhaust sleeves.
- A supervisory control and data system that allows remote monitoring of plantroom and cable conditions, continuously logging relative humidity, temperature, flow and pressure in the cables.
The award-winning project was completed in 2015, on time and on budget. Since then it has received extensive local and international recognition.
