MBTA SILVER LINE, PHASE III

Boston, Massachusetts


“The Silver Line is Boston’s first Bus Rapid Transit Service. This far reaching project will launch the Silver Line route in three phases. When all three phases are complete, it will travel from Dudley Square to Logan Airport via Downtown and the South Boston Waterfront.” Massachusetts Bay Transportation Authority

As members of the URS/DMJM Harris, Joint Venture, ASEC Corporation has been contracted to perform survey and mapping services for Phase III of the MBTA’s Silver Line Transit Project.

Phase III design will entail a tunnel which will connect to Phase II at South Station (currently under construction) and Phase I at Washington Street (in operation). It will have platform connections with the Green Line at Boylston Street Station and with the Orange Line at the Chinatown (Essex) Station. This will complete the new bus transit line connection from Forest Hills to Logan Airport. The tunnel will start with a boat section on Washington Street just North of Oak Street and South of the New England Medical Center Garage. It will then turn North at Tremont Street and continue onto the Boylston Street Green Line Station. It then turns East down Boylston and Essex Streets and will meet Phase II at Atlantic Avenue near South Station. The limit of survey work will begin at the intersection of Tremont, Oak and Washington Streets, and end at Atlantic Avenue.

ASEC’s responsibilities will include:

  • Establishing the vertical and horizontal control based on Central Artery/Ted Williams Tunnel (CA/TWT) Datum and set benchmarks (BMs) at 750’ intervals.

  • Re-survey of boundary lines affecting the project for potential takings necessary for construction.

  • Performing a topographic and cross-section survey of the project corridor extending 100’ on adjacent streets and invert elevations of sanitary and storm water structures.

  • Underground mapping will include portions of Boylston Street, Chinatown and New England Medical Center Stations along with part of the abandoned West Route subway tunnel under Tremont Street.

  • Mapping of underground utilities will be an important and major portion of this project. Accurate locations are imperative to a good design. The entire route is located within busy and congested streets that are intertwined with various utilities. Using accurate existing conditions surveys and record plans we will be creating a complete base map of the entire route. We will also be utilizing vacuum excavation in some critical areas to obtain exact locations of utilities that may have to be moved or supported during construction.



    CLIENT:
    URS/DMJM Harris, JV
    38 Chauncy Street
    Boston, MA 02110

    OWNER:
    Massachusetts Bay Transportation Authority
    10 Park Plaza
    Boston, MA 02116

    CONTRACT FEE:
    $771,000