According to the Maine Department of Transportation, a rebuilt version of the Sarah Mildred Long Bridge – spanning the US 1 Bypass over the Piscataqua River between Portsmouth, N.H., and Kittery, Maine, is on pace to re-open to traffic by mid-to-late November. In 2016, the bridge was demolished as part of a project called the Three Bridge Agreement.
After the old bridge was demolished, construction of the new bridge began right away. Plans for the new bridge included vertical clearance for larger ships and a steel box lift span capable of carrying vehicle and railroad traffic above the steel superstructure. The project also called for a lightweight solution that could stabilize the bridge during severe weather conditions and deflect high winds.
To meet those requirements, engineers turned to Dayton, Ohio-based manufacturer and turnkey supplier Composite Advantage for two sets of fiber-reinforced polymer (FRP) wind fairings. As the company explains, the wind fairings will stabilize the bridge during severe weather conditions.
“Light weight is a critical component for a lift span,” explains Composite Advantage President Scott Reeve. “FRP material is a good choice for several reasons. It can be molded to provide an optimum shape and its’ corrosion-resistant characteristics contribute to a long design life.”
The L-shaped FRP wind fairings—the first such product for Composite Advantage and only the second time FRP has been used for this type of application—attach to the top and bottom of the lift span structure.
“The product improves the aerodynamic performance of the span and eliminates the potential for undesirable dynamic responses,” says Reeve. Each fairing contains an internal pedestrian walkway to accommodate inspection and maintenance activities.
The ultimate goal is for the bridge to outlast its predecessor. For more information and updates on the bridge, visit http://maine.gov/mdot/sml/.