Parsippany, N.J. — Acrow Bridge provided a temporary lift bridge over the Intracoastal Waterway and Lake Worth Lagoon that helped avoid serious disruption to both road and water traffic there. The temporary bridge on Southern Boulevard connects the Town of Palm Beach at the Mar a Lago Club and the City of West Palm Beach. It is expected to be in place until completion of the project, now estimated for early winter 2020.
When structural problems were found with the existing bascule bridge, it was determined that a new structure was needed, including a temporary lift span during the lengthy construction to accommodate heavy vehicle traffic on the roadway as well as commercial and recreational vessel travel in the waterway below.
The lift span purchased from Acrow is 170 feet long with a roadway width of 30 feet and a 5-foot-wide cantilevered footwalk. It uses four, 75-foot towers and a 175-foot gantry system located on top of the towers. The structure is designed for an AASHTO HL-93 loading. It was particularly important when planning the detour that the temporary structure have superior structural strength, reliability and durability as the bridge is required to be lifted every 30 minutes for vessel passage.
Scott Patterson, VP Engineering of Acrow Bridge said, “Lift bridges always pose technical challenges and there were many steps involved in the planned installation of the temporary bridge, requiring close coordination between Acrow’s mechanical, structural and electrical team members and the contractor. The lift span, towers and machinery span were all assembled from Acrow truss panel components on-site and nearby. Large cranes were then used to lift them into place. Additionally, the tower top cross-beams and mechanical systems were installed using a crane.”
Added Acrow CEO Bill Killeen, “Like many other Acrow projects, the Southern Boulevard project’s ultimate success in terms of safety and cost efficiency involves the use of a long-term detour structure that eliminates disruption to the communities around it. We are pleased to have worked closely with the Florida Department of Transportation and its contractor on this important project.”
The project contractor is Johnson Brothers, a division of Southland Holdings, and the project owner is the Florida Department of Transportation. The design engineer is AECOM Technical Services of Tampa.