Construction began Jan. 2 on a $76-million replacement for an 87-year-old Amtrak bridge spanning the Thames River in New London, Conn. Under a contract awarded in October, Cianbro Corp., Pittsfield, Maine, will replace the bridge's bascule section with a new lift span, Amtrak Acting President and CEO David Hughes told reporters in a Jan. 11 telephone conference call. HNTB is the design firm for the project.
|Rendering of new lift section of bridge over Thames River.(Illustration courtesy of Amtrak)|
The project will take more than two years to complete. Amtrak estimates the key milestone will occur in November 2007, when contractors will remove the existing bascule section and its 4-million-pound counterweight. Barges will deliver a 450-ton vertical lift span for replacement. While that phase of the work is carried out, rail service will be halted at New London for four days, and passengers will cross the river by bus.
The current crossing's entire length is 1,389 ft., but the section to be replaced is 188 ft. long. Jim Richter, Amtrak's deputy chief engineer for structures, says plans call for extending two of the current bridge piers to accommodate two towers to be built for the lift span. He says the towers will be about 150 to 160 ft tall. The width of the section is about 35 ft.
Hughes said there have been a number of incidents in which parts of the current bridge "failed or nearly failed." He said that in 2004 three trunnion bolts broke. Richter says that if there is a trunnion problem, the bascule section "could seize up" while it's in the open position, halting rail traffic in that part of the Northeast Corridor.
The Thames bridge had about 2,500 openings in 2004, many more than envisioned years ago, said Hughes.
Hughes, Amtrak's former chief engineer, became the railroad's acting president in November when its board dismissed David L. Gunn from the top post. Gunn didn't pursue a restructuring program as aggressively as the directors wanted and opposed a plan to split Northeast Corridor operations from the organization, whose formal name is the National Railroad Passenger Corp.
Hughes said that because of Amtrak's limited capital budget "it has been all but impossible to commit this amount of funding for a single project." But he said that Amtrak now would try to keep one big project under way at any given time, if congressionally approved capital funding remains relatively constant. In fiscal year 2006, Hughes says Amtrak has budgeted about $380 million for capital infrastructure work.
Beyond the Thames bridge, Hughes says, "We do have more to do." Two other major projects are planned in Connecticut to replace bascule structures built in 1907. One is a replacement for the Niantic River bridge, with construction to start in 2008 as the Thames bridge work wraps up. The other spans the Connecticut River at Old Saybrook. Amtrak plans to issue a request for proposals to study whether that bridge should be rebuilt or replaced. Construction could begin in 2010.