by Ken Krause
A proposed Phased Approach to construction of the Green Line Extension would begin with bridge work next year and provide Green Line service to parts of Somerville by the end of 2016, but Medford and most of Somerville would still not likely see Green Line service until mid-2019.
Last Thursday, officials from the MBTA and the HDR/Gilbane project team presented details of the Phased Approach to municipal and elected officials that make up a Green Line Extension Steering Group charged with finding ways to accelerate the long-delayed project.
Phase I of the project would begin in Fall 2012 and include the reconstruction of the railroad bridges over Medford Street in Somerville and Harvard Street in Medford. The bridges currently carry commuter rail, Amtrak and freight trains but must be widened to accommodate two additional Green Line tracks.
Project officials said these bridges were selected because they have the fewest utilities to relocate and require little or no property acquisition.
The Harvard Street bridge work will include new retaining walls and changes to address flooding that currently occurs on Harvard Street. It also will include a grade adjustment to the tracks extending 650 feet on either side of the bridge.
Officials estimated the bridge work would be completed in January 2014. Phase I also would include demolition of an MBTA building near North Point that would provide replacement parking during the Lechmere Station relocation work.
Here is how officials outlined the rest of the Phased Approach, during which work would overlap:
Phase 2: Construct the relocated Lechmere Station (including a bus station), Washington Street Station and Union Square Station; rebuild Washington Street railroad bridge; institute road, traffic and pedestrian improvements; and open Green Line service to Washington Street/Brickbotton and Union Square Stations (Start: Mid-2013; Finish, end of 2016, with service to Washington Street and Union Square).
Phase 3: Build the new maintenance facility and storage yard adjacent to the Boston Engine Terminal in Somerville, which officials said are needed to support Phase 4. (Start, TBD, depending on property acquisition timeline; Finish: End of 2017).
Phase 4: Construct the remainder of Medford Branch extension to College Avenue, with stations at Gilman Square and Lowell Street in Somerville, and Ball Square and College Avenue in Medford (Start, early 2014; Finish, June 2019 – midpoint of the current 2018-2020 estimate).
Project officials also are evaluating the possibility of using a Construction Manager/General Contractor delivery method (as opposed to Design/Build) to try to speed up construction. A CM/GC process is being developed for the Longfellow Bridge project.
The next meeting of the Steering Group is scheduled for Thursday, October 13, from 2:30 to 3:45 p.m. in Room 4150 of the State Transportation Building, 10 Park Plaza, Boston.