Underground Railroad: A Peek inside New York City's Subway Line of the Future

Join Our Community of Science Lovers!

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

Sixty-five feet below the streets of Manhattan, workers are digging the city’s first new subway line since the 1940s. The Second Avenue subway, to be named the T line, will eventually stretch from 125th Street in East Harlem to Hanover Square in the financial district. The first stretch of the line, from 96th Street to 63rd Street, is set to open in December 2016, carrying more than 200,000 passengers every day.

Scientific American visited the base of operations for the dig this past April, as engineers completed the downtown tunnel and set to work on the uptown side. A 700-foot-long tunnel-boring machine, or TBM, does the actual digging, moving at a rate of up to 100 feet a day through the city’s bedrock, a blend of granite, mica, gneiss and garnet known as Manhattan schist. “The rock in the tunnel is twice as strong as concrete, and still the TBM cuts through it like a piece of cake,” says project manager Alaeden Jlelaty of Swedish construction firm Skanska. The TBM, nicknamed “Adi” for the granddaughter of an MTA official, delivers 2.99 million pounds of thrust, the equivalent of 12 Boeing 747s.

Little of the rock the machine shatters goes to waste. Each day trucks deliver debris from the tunnel to construction sites around the city, where it is used for landscaping and land reclamation.

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American