Construction will start this month on the long-awaited replacement of a rail drawbridge that crosses the Charles River outside North Station, a $1.06 billion project that’s scheduled to last through 2032 — all without interrupting train service.
A joint venture led by Swedish construction giant Skanska will replace the two nearly century-old bascule bridges and 1.5 miles of train tracks, along with adding a station platform and two train tracks to the 10 already operating out of North Station.
“By leveraging innovative design and construction solutions, our team will deliver a future-ready rail network while maintaining uninterrupted service for the passengers who rely on it every day,” said Paul Pedini, senior vice president of Skanska USA Civil, in a statement.
The project will also replace the control tower where crews manage 200 daily train trips and access for water traffic on the Charles River beneath the bridge. Some 11 million riders on MBTA Commuter Rail and Amtrak trains pass over the bridges each year.
The project in 2024 won $472 million in federal funding from the US Department of Transportation, and the MBTA board of directors in March voted to award the project to a joint venture of Skanska Civil Northeast and Koch.
The drawbridge replacements are expected to last at least 75 to 100 years. Watertown-based VHB Inc. is the project’s designer.
“The replacement of the Draw One bridges is one of the most significant infrastructure investments in the MBTA Commuter Rail system,” said Rick Carey, project manager with VHB, in a statement. “Once complete, these new structures will deliver lasting benefits to one of the region’s busiest transportation corridors.”
There will be “temporary disruptions” to MBTA and Amtrak service on weekends, when train traffic is “less aggressive” than during the work week, said Karl Eckstrom, the MBTA’s deputy chief of structures overseeing the Draw One Bridge replacement project, at a January 2025 hearing on the project.
That will allow operations to maintain a relatively normal pace, “with some of the bridge tracks being constricted during the weekend,” Eckstrom said at that 2025 meeting.
“Weekend-only interruptions to commuter rail service will be accommodated through reliance on the existing subway and public bus services if needed,” Eckstrom said then. “The MBTA will coordinate construction activities to ensure that there are no interruptions or significant impacts to commuter rail or Amtrak service, and also to minimize any effects of construction.”
Construction crews will also use portions of a parking lot outside a Massachusetts General Hospital administrative building on the downtown side of the river. The MGH building is one of 13 constraints the project’s construction, design, and engineering teams have to work around, along with Boston Sand & Gravel’s industrial campus in Charlestown, the city’s Duck Boat Tour ramp at Miller’s River, and the Zakim Bridge overhead.
Catherine Carlock can be reached at catherine.carlock@globe.com. Follow her @bycathcarlock.