The Metropolitan Transportation Authority (MTA) opened a new $75 million passageway on Tuesday, February 25^th, designed to reduce congestion between the No. 7 line train platform and the mezzanine at Grand Central Station-East 42nd Street. The project was completed on time and under budget.

The new passageway tunnel was excavated using a combination of mechanica means and using “controlled, low-velocity explosions” to break through Manhattan’s notoriously hard bedrock known as the Manhattan schist. The passageway marks the first time this technique has been used in the subway said the transit agency. Despite the drilling and deflagration of rock, train service remained uninterrupted as tunnel workers, “Sandhogs” worked beneath Midtown streets.

MTA Chair Janno Lieber highlighted that 150,000 passengers exit the 7 train at this station daily—comparable to the entire daily ridership of San Francisco’s BART system. The project also included new lighting, freshly painted platform walls, 400 fire alarms, and 75 new light fixtures.

This new passageway is part of the larger “Grand Central Station-East 42 Street Circulation Improvement Project,” which will introduce new escalators, fare gates, and accessibility upgrades at the 42nd Street-Bryant Park station. The full project is expected to be completed later this year.

GZ previously developed preliminary designs, participated in selecting contracting strategies, and reviewed various design submissions and specifications from the design-builder. Subsequently, GZ Consultants provided Construction Management support to the MTA and NAIK during the construction works at Grand Central Station, with an assigned Resident Engineer position for the construction of the Passageway Tunnel. The Resident Engineer was responsible for verifying the tunnel excavation means and methods with different types of ground support, installation of the waterproofing PVC membrane system including grouting, shotcreting the final liner, and the architectural finishes within the New Passageway.

GZ Consultants would like to congratulate the MTA and its partners on this great achievement, and we are proud to be part of this remarkably intricate infrastructure project.

To read more about GZ’s involvement in the project, visit our project page.

For complete Gothamist article please visit this site.

Group photo showing part of the site support team consisting of the MTA, Skanska and NAIK. GZ’s Senior Tunnel Engineer Louis Falco supporting NAIK’s team in the role as the Resident Enigneer can be seen kneeling in the middle of the picture. (Image Courtesy of MTA)

A video released by the MTA showcases controlled blasts in a darkened tunnel, resembling heavy-duty fireworks (Courtesy of MTA).