Project: Memorial Lift Bridge Replacement. Grid Manufacturer: LB Foster 

Location: Portsmouth, NH / Kittery, ME   Contractor: Archer Western 

Install Date: 2012-2013  Design Engineering Company: HNTB Corporation

Bridge Owner: New Hampshire DOT and Maine DOT 

 

Project Description: The Memorial Bridge is an iconic structure which carries nearly 20,000 vehicles per day traversing the Piscataqua River between Kittery, ME and Portsmouth, NH. One of the most important aspects of the replacement project was speed of construction, which was required to limit the impacts to the traveling public. The 10,000 square foot lift span was completely fabricated offsite and floated into place to accelerate the project, which was completed approximately one month ahead of the 19 month pledged delivery schedule. 

Notable Features of Project: The owners wanted a solid riding surface, so the new lift span utilized a lightweight Exodermic® deck. Not only was the deck weight critical because it’s a lift bridge, but also due to the construction method used to deliver the project. The strength of the Exodermic® deck also allowed the design engineers to span the deck across floorbeams, eliminating the need for stringers which saved additional weight and cost.