Red Line & Orange Line Strengthening of Bridges

Massachusetts Bay Transportation Authority | Boston, MA
Orange Line Bridge over Adams Street n Malden, Massachusetts

As part of the Red Line/Orange Line Improvements Program, Benesch provided consulting services to the Massachusetts Bay Transit Authority (MBTA) for the design of structural strengthening of bridges to provide adequate structural strength and fatigue capacity under the new transit vehicle loading.

The new vehicles provide enhanced MBTA passenger experience, and as part of the commitment to customer service, the strengthening of the bridges permit the new vehicles to travel at intended design speeds.

Benesch’s services included developing Preliminary Strengthening Studies for the bridges; providing detailed calculations, plans and sequences of construction for the strengthening; working closely with the MBTA bridge contractors to determine how much work could be performed within non-revenue hours each night; design of field modifications; shop drawing reviews and updating the load ratings.

After a review of previous load ratings, inspection reports and preliminary calculations, the following structures were strengthened and/or have found reserve capacity based on as-built conditions:


  • Red Line over Conley Street
  • Red Line over Fields Corner Busway
  • Red Line – Longfellow Approach
  • Red Line over Victory Road
  • Red Line over Geneva Avenue


  • Red Line over Granite Spur


  • Orange Line over Charles Street
  • Orange Line over Adams Street


  • Red Line – Wollaston Station

Work also included the development of traffic control for the vehicular, pedestrian, and rail vehicles such that impacts were minimized including limitation of work hours to keep revenue rail vehicles in service during revenue hours.