Sarah Mildred Long Bridge Replacement

Kittery, ME

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.


AGC Build Maine Award
PTI Award of Excellence
ENR New England Best Highway/Bridge
ENR New England Excellence in Safety Award of Merit
ENR New England Project of the Year
ABC NH/VT Excellence in Construction
ABC NH/VT Best Practices Community Service Award of Merit
ABC NH/VT Chairman's Award - Best of the Best