WASHINGTON – The nearly 100-year-old Thames River Bridge between New London, Conn., and Groton, Conn., will undergo a $76 million replacement of its aging bascule lift span under a construction contract between Amtrak and Pittsfield, Maine-based Cianbro Corp., the parties announced.
The construction project will take two years to complete and is the largest single capital improvement Amtrak will make to the Northeast Corridor during this time. Work on the project begins this month on the installation of seven new underwater communications and signal submarine cables.
In the most dramatic phase of the construction project to occur over 12 days during fall 2007, the bascule lift or movable center portion of the bridge will be removed, a 188-foot long, 35-foot wide, and 1,250 ton vertical lift will be floated into place on barges from Long Island Sound and attached to the bridge. This will result in a four-day outage of this section of the railroad, during which Amtrak plans to establish a "bus bridge" in Connecticut connecting passengers to trains in the direction of New York and Boston; details will be released in 2007.
Constructed in 1919, the Thames River Bridge is located between New London and Groton. The bridge lift is currently operated by machinery parts that have reached the end of their lifespan.
The project is the first of three major movable bridge replacements in Connecticut planned over the next 10 years. Virtually all work will be done while the railroad continues to operate, with minimal interruptions during the multi-year job.
Lasting until early 2008, the Thames River Bridge project will include the fabrication and erection of two lift towers and a lift span, re-location of the bridge tender’s control house, the installation of new machinery, electrical systems and underwater communications and signal cable. The project also calls for modification of the piers and the marine fender system that protects the piers from marine traffic.
"The aged drawbridge will be replaced by a more efficient vertical lift bridge that rises between two towers," said Peter Finch, Amtrak project engineer. "Once that is complete, rail passengers will be able to depend on a reliably operating lift span for the better part of this century."
Amtrak’s Bridge & Building department will assist Cianbro Corp. with the relocation of the bridge tender’s control house, which contains the electrical controls, machinery and back-up engine generator to operate the bridge. The new lift span, constructed by Cianbro, will have new track and walkways.
Amtrak will assist Cianbro with the installation of new timber ties and tie spacers and Amtrak crews will install the running rails, guard rails joint bars and tie plates.
Amtrak electrical crews will extend existing power and control cables and monitor the installation of the new power control system, replace the navigation lights on the bridge and install lighting on the new pier fenders. New signal system cables and telephone service to the control house will also be installed.
During the course of the project, the impact to rail service will be minimal, with no major outages except when the bridge span is changed out, according to Amtrak. The final phase will take place in late 2007, when a four-day shutdown of the railroad will occur.
The project’s effect on maritime traffic will also be minimal, with the work schedule being coordinated with the boating community, submarine base and Coast Guard. Once installed, the new lift span is expected to improve the reliability of both rail and marine traffic by minimizing bridge mechanical problems.
The Thames River Bridge project is part of a comprehensive infrastructure program in the Northeast. Over the past three years, considerable progress has been made including the installation of 439,000 new concrete ties, 188,000 wood ties, and 225 rail miles of continuous welded rail.
Amtrak crews have also undercut 80 miles of track, installed 398 switches, retimbered 65 bridges and renewed 243 miles of electric catenary hardware. Earlier this year, Amtrak Engineering began the Rhode Island Freight Rail Improvement project and, in 2006 will begin the construction of a new interlocking in Niantic, Conn.