Project Detail

Sarah Mildred Long Bridge Replacement

Kittery, ME

The Sarah Mildred Long project has received over ten project awards, including the National Best of the Best in the Highway/Bridge category from ENR.

Scope of Work

As the Construction Manager/General Contractor (CM/GC), Cianbro constructed the Sarah Mildred Long Bridge replacement structure located on the Piscataqua River. The existing steel vertical-lift bridge carries the U.S. Route 1 Bypass, providing a critical link between Kittery, Maine, and Portsmouth, New Hampshire. The new 2,800-foot concrete vertical-lift bridge was constructed at a higher elevation than the existing, with a vehicular structure stacked over a railroad level, as well as a longer lift span at 300 feet.

Project Details

  • Removed existing structures
  • Constructed concrete roadway and railroad superstructures
  • Constructed a high-quality and reliable 4,000,000 pound 300-foot long steel lift span
  • Constructed four angular lift span towers
  • Avoided and minimized project impacts to the roadway, railway, and maritime traffic; local businesses; and communities during construction
  • Erected 500 precast concrete segments, including 126 precast railroad segments, 229 precast vehicular segments, and 88 precast tower segments
  • Installed four 20 foot-diameter, 100-ton counterweight sheaves
  • Installed 29 drilled shafts, composed of 8,000 yards of concrete and 3,000,000 pounds of rebar
    • An additional 20,000 yards of concrete containing over 2,500,000 pounds of rebar were cast-in-place on the project
  • Over 300 miles of post-tensioning strand was installed, tensioned and encased in nearly 12,000 bags of "cable" grout
  • Over 200 team members on site at the project's peak
  • Managed environmental time of year restrictions, in water work windows, hydroacoustic and turbidity monitoring

Lean, Innovative, and Unique Project Solutions

As a member of the Integrated Project Team (IPT), Cianbro worked collaboratively with the Maine and New Hampshire Departments of Transportation as well as Figg Engineering and Hardesty & Hanover, on New England’s first CM/GC alternative delivery bridge project. Cianbro maximized the benefits of the CM/GC process by focusing on the design and construction approach to enhance safety, improve schedule, and increase project value while adhering to the budgetary goals.