The MBTA’s Red Line and Blue Line are the only two lines in Boston’s subway system that do not connect at any point. The objective of this project is to extend the Blue Line from the Bowdoin station approximately 1,500 feet underneath Cambridge Street and connect it with the Red Line at the Charles/MGH station. Creating this connection will greatly increase ridership and relieve congestion at numerous transfer stations. It will allow residents of the North Shore, Cambridge, Beacon Hill, and East Boston much easier access to Downtown Boston. In addition, it is believed that the project will also decrease automobile emissions and improve air quality in the surrounding area.
To create this tunnel, the project team studied a no-build alternative and two build alternatives: one involving the elimination of Bowdoin Station and one involving the relocation of the station. For the tunnel construction, the cut-and-cover method and the mined method were each evaluated. Ultimately, the elimination of Bowdoin station with the mined method of tunnel construction was determined to be the best suited to this project due to the locations of underground utilities.
C&C’s responsibilities within this project include civil and structural support and utility design. Our utility work required intensive coordination with the Boston Water and Sewer Commission, Massachusetts Water Resources Authority, and National Grid.