A new Orange Line station is under construction between Wellington and Sullivan Square Stations. Once constructed, this new station will serve as a gateway to development at Assembly Square.
Construction of this new Orange Line station, called the Assembly Station Project, is well underway. Between July 2012 and February 2013, the project has completed the subway track infrastructure that will allow train traffic to be shifted east. This shift creates space for Assembly Station's future platforms. Moreover, the work throughout these last few months has included rehabilitating the test track, reconfiguring the third rail, and relocating the signal and communication systems. This work was performed directly on the Orange Line tracks and could not be completed while trains were running. Major portions of the track work were performed during scheduled weekend diversions between Oak Grove and Sullivan Square Stations. In addition, the "early access nights," in which Orange Line service was suspended between Oak Grove and Sullivan Square at 9:00 p.m. Sundays through Thursdays, provided a six-hour window that greatly accelerated the schedule and allowed for the infrastructure work to be completed by December 2012.
Since January 2013, installation of the concrete piles has been performed during Orange Line weekend diversions. The concrete piles support the new southbound tracks and platform areas of the future Assembly Station. Due to the size of the equipment involved and the proximity to the right-of-way area of the tracks, it was determined that this work needed to be performed on the weekends with a shuttle bus diversion in place. To accommodate this operation, the weekend diversions have been scheduled through March 9, 2013. Early access is slated to resume in June 2013.
The decision to perform work on the weekends or during early access nights was made after careful reviews of service impacts and overall safety. Due to the size and scale of the construction activities being performed at the Assembly Station Project at this time, early access and weekend work involving shuttle bus diversions are unfortunately unavoidable.
Upon completion in approximately Fall 2014, Assembly Station will service the Assembly Square redevelopment district in Somerville, the site of a proposed large-scale, mixed-use redevelopment project of 2,100 residential units, more than 2.75 million square feet of retail and office space, and a 200-room hotel.