Green Line Signal Renewal Project

Client: Massachusetts Bay Transportation Authority
Location: Boston, Mass.
Construction Cost: $6.2 million

Gannett Fleming contributed to the redesign of three passenger stations along Massachusetts Bay Transportation Authority’s (MBTA) Green Line as part of a team. Our firm was responsible for the signal design and renewal of the signal system between Haymarket and Science Park stations. As part of the overall redevelopment of the North Station area, a new superstation integrating the Green and Orange Lines was constructed through a preceding contract. The redesign of Boston’s Central Artery, the “Big Dig,” necessitated the relocation and reconfiguration of a 3/4-mile section of the MBTA’s Green Line.

Our firm produced two designs for this project. When the existing elevated structure from North Station to Science Park was retired to accommodate highway construction, an interim design providing for an end-of-line turnback facility needed to be put in place. The facility utilized microprocessor interlocking equipment. The permanent design was constructed once the expressway work was completed. The new design includes a viaduct with a 6.5 percent grade, linking the turnback area to the existing elevated Science Park Station. Our firm completed work for this project without interrupting Green Line service for the critical North Station.

Services Provided:

• Signal design
• Construction staging
• Signal power.

Special Features:

• Microprocessor interlocking
• 100 Hz track circuits
• Central control/local control panel.