AECOM’s main cable dehumidification system project for the William Preston Lane Jr. Memorial Bridge (also known as the Bay Bridge) has recently won a 2016 Engineering Excellence Award (EEA) from the American Council of Engineering Companies (ACEC) in the Honor Award category.
The Bay Bridge, operated by the Maryland Transportation Authority (MDTA), consists of a dual-span crossing rising 186 feet over the Chesapeake Bay. With an annual traffic volume approaching 26 million cars, these vital bridges connect the ocean destinations on Maryland’s Eastern Shore with the urban centers of Baltimore, Annapolis and Washington, D.C. When inspections revealed that the cable corrosion protection systems were not adequate — similar to findings on cables of other suspension bridges worldwide — MDTA turned to AECOM, whose suspension bridge team is recognized globally as leaders in the field of cable dehumidification.
AECOM designed and specified a cable dehumidification system for both the Eastbound and Westbound Bridges and provided onsite specialist field support and construction administration during system installation. The dehumidification system injects dry air into the bridge’s main cables to remove built-up moisture and maintain a dry, non-corrosive environment. A web-based control and monitoring system records key data, such as relative humidity and air flow, and allows MDTA staff to remotely monitor the system. All work necessary to seal the main cables with a robust, air-tight and weather-resistant coating was safely completed while the bridge remained open to traffic.
The Westbound Bridge system was commissioned over two years ago and in that time approximately 700 gallons of water have been removed from the cables and non-corrosive humidity levels are being maintained within the cables. The Eastbound Bridge system has been operational for approximately six months with sections of the cable already achieving non-corrosive levels. A total of nearly 220 equivalent gallons of water have been removed from the cables to date.
“We are honored to receive this award,” said AECOM’s Barry Colford, vice president and leader of the complex bridge preservation practice. “The Bay Bridge represents the first full length application of cable dehumidification technology in North America, allowing this majestic structure to achieve a prolonged service life. The successful outcome of this project is changing the way suspension bridge owners in the United States and beyond maintain bridge cables.”
Since 1967, ACEC’s EEA competition pays tribute to exemplary achievements throughout the world and honors the year’s most outstanding engineering accomplishments. The national EEA awards program names 16 honor award winners, eight grand award winners and one grand conceptor award winner each year. This year’s EEA awards were recognized at the Engineering Excellence Awards Gala on April 19.