After three decades of advocacy, Boston is set to electrify the Fairmount Line with battery-powered trains, signaling a shift in how American cities approach cleaner transit.
For years. Marvin Martin stood in the Four Corners area of Dorchester and watched trains roll past on the Fairmount Line. bound for downtown Boston. The cars were often filled with commuters, leaving residents in his neighborhood to crowd into buses instead. It was a disparity that didn’t sit right with him. fueling a campaign that lasted the better part of a generation.
Martin. the retired head of the transit advocacy group Action For Equity. began pressuring the Massachusetts Bay Transportation Authority (MBTA) in 1995 to expand service. His persistence eventually reshaped the line: three stops were added in Dorchester between 2012 and 2013. followed by a fourth in Mattapan in 2019. Now. nearly 30 years after his first effort. the T is set to transform the line again. moving to replace diesel locomotives with battery-powered technology.
Under a deal expected to cost $765 million, the agency will lease seven battery-powered trains, each featuring four cars, for 15 years. Built by the Swiss manufacturer Stadler and slated for service by 2030. these trains represent a cautious but significant step toward modernization. The project aims to increase the frequency of stops along the 10-mile route from every 30 minutes to every 20. while cutting 17. 700 tons of carbon dioxide emissions annually.
“We want a train that would not be spewing a bunch of toxic particulates into the air,” Martin says. His push for electrification—meant to spare local lungs the heavy burden of diesel exhaust—is finally becoming reality.
This transition arrives as transit agencies across the U.S. grapple with the best path toward decarbonization. While overhead power lines, or catenary, are the traditional standard for electric rail, the infrastructure costs can be immense. Battery-powered trains offer a more flexible alternative, though the technology remains largely unproven at the scale of daily high-ridership routes. Systems in the San Francisco Bay Area and Chicago are watching closely. with Caltrain and Metra currently planning their own battery-electric implementations by 2028.
Historical precedents loom large in these decisions. Boston, which launched the country’s first electric subway with the Tremont Street line, is no stranger to such shifts. Yet. as Kennesaw State University history professor Albert Churella notes. the allure of technological “cure-alls” has historically led to both progress and disappointment in the rail industry. Meanwhile. Nicholas Dagen Bloom. author of *The Great American Transit Disaster*. points out that most commuter lines historically favored diesel for its cost-effectiveness and lack of need for expensive wire infrastructure.
Real-world results from other regions offer a baseline for success. Caltrain’s shift to overhead electric lines this year saw commute times drop by 23 percent due to faster acceleration. accompanied by a 60 percent surge in ridership. Research from UC Berkeley environmental engineer Joshua Apte found that riders’ exposure to black carbon on that line plummeted by 89 percent—a level of improvement typically seen after decades of regulation.
While battery-powered units may be slightly less efficient than those powered by overhead lines. they remain a powerful tool for environmental health. The transit industry is increasingly diversifying its approach; the MBTA itself plans to utilize a mix of battery and catenary-powered trains on its Providence Line. For manufacturers like Alstrom. which operates battery-powered routes in Germany. the urgency is driven as much by finances as by climate. with diesel prices hitting $6.32 a gallon this Monday. up significantly from $3.70 a year ago.
For Martin, the arrival of cleaner, quieter trains is a long-awaited victory. While the diesel exhaust will continue to linger until the new fleet arrives, he considers the three-decade struggle a success. The “novel thing” coming to Four Corners won’t just be the tech; it will be the confirmation that his neighborhood is finally part of the city’s transit future.
“I’m pretty satisfied with where we ended up,” he says. “As long as we still get that train.”
MBTA Fairmount Line Boston transit rail electrification battery-powered trains transit advocacy urban planning Marvin Martin