NEW YORK, NY – STV, a leading professional services firm that plans, designs and manages infrastructure projects across North America, joins the Metropolitan Transportation Authority (MTA) in celebrating the completion of the new passenger tunnel connecting Grand Central Terminal to the No. 7 Subway Line’s Grand Central-42nd Street station. Serving as the designer- and engineer-of-record, STV was a key part of the design-build team led by Skanska that helped deliver this complex underground connector.
To commemorate this significant milestone, the MTA hosted a community ribbon cutting ceremony at the iconic Grand Central Terminal on Tuesday, February 25, 2025. During the event, local officials and community leaders toured the underground passageway, which will significantly improve passenger circulation between the subway station and terminal, which experiences over 500,000 visitors every day.
“This new tunnel is a transformative investment in the MTA’s transit network, enhancing connectivity and creating a more efficient transfer experience for millions of visitors utilizing Grand Central Terminal every week,” said Peter Pappas, PE, senior vice president and New York metro area manager at STV. “The team successfully navigated the complex challenges of working beneath one of the city’s busiest transit hubs to deliver a more seamless connection for the community.”
Construction beneath East 42nd Street and Lexington Avenue required working near buildings, underground structures and utilities, with minimal flexibility for adjustments. The project involved extensive rock excavation using Sequential Excavation Methods (SEM) – a highly adaptable tunneling technique that systematically excavates and supports smaller sections of the tunnel to maintain ground stability, while maintaining uninterrupted service on the busy subway line. This innovative method, coupled with specialized equipment such as Brokk-mounted drills and hydraulic machinery, enabled the team to perform precise drilling, breaking and excavation. The team also employed advanced 3D Finite Element Analysis – a computerized modeling method that predicts how structures will react to real-world forces – to ensure the tunnel’s structural integrity. This approach resulted in a tunnel design that prioritized stability and public safety under shallow rock cover while minimizing ground settlement, groundwater seepage and construction impacts on existing utilities.
STV’s long-term partnerships with MTA spans several notable projects, including Grand Central Madison, Long Island Rail Road Elmont-UBS Arena Station, Mother Clara Hale Bus Depot and accessibility improvements at New York City Subway and Staten Island Railway stations. Grand Central Madison won the 2025 American Society of Civil Engineering’s Outstanding Civil Engineeering Achievement (ASCE OCEA) award, recognizing STV and its joint venture partners’ work providing tunnel engineering, environmental engineering and final design services.
