Four 1970s-era traction power substations were scheduled to be replaced by the Massachusetts Bay Transportation Authority (MBTA). STV provided engineering design and construction phase services as part of this $31 million modernization project. The four substations serve the Orange Line on the Haymarket North Extension at Sullivan Square, Wellington, Malden, and Oak Grove.

Maintaining the operations of the MBTA subway system was a major challenge of the project. The project scope also included the replacement of 13.8-kV switchgears, traction power transformers and auxiliary station service transformers, and DC switchgears. All AC and DC equipment was replaced, along with supervisory control and STB cabinets. Once complete, the four substations will be the first in the MBTA system to be fully automated.