Serving more than 500,000 daily visitors, Grand Central Terminal and the Grand Central-42nd Street No. 7 Line station form one of the busiest passenger hubs in the world. To improve circulation between the terminal and the subway, the Metropolitan Transportation Authority advanced a project to construct a new underground pedestrian tunnel. As part of the Skanska‑led design‑build team, STV served as lead designer for this highly complex connector beneath East 42nd Street and Lexington Avenue.
What challenges did STV address?
Working just feet below active streets, transit structures and dense utility networks required exceptional precision and construction methods that protected nearby buildings and kept the No. 7 Line in full operation. Shallow rock cover and tight urban constraints limited flexibility, demanding tunneling solutions that ensured stability and minimized settlement.
What solutions did STV deliver?
STV deployed Sequential Excavation Methods (SEM), allowing teams to remove and support small sections of rock in stages while maintaining ground stability. Specialized Brokk‑mounted drilling and hydraulic machinery improved precision in confined spaces. STV also used advanced 3‑D Finite Element Analysis to model real‑world forces and predict structural behavior. This approach yielded a safe, resilient tunnel that reduced groundwater seepage and protected existing utilities.
How does this project benefit the community?
The new connector improves pedestrian flow, reduces congestion and enhances the passenger experience at New York’s busiest transit crossroads. It strengthens access between major rail and subway systems, enhancing mobility for commuters and visitors.
Key stats and accolades
- 1.7‑mile‑long No. 7 Line corridor serves 500,000+ daily visitors
- SEM tunneling used beneath 42nd Street
- 3D Finite Element Analysis for stability planning
- Continuous subway service maintained during construction
