Boring Begins for Hudson Tunnel Project
The Gateway Development Commission (GDC) on Sept. 28 celebrated the start of tunnel boring for the Hudson Tunnel Project. In the coming days, final testing will be completed and the first tunnel boring machine that will be used to build the new train tunnel under the Hudson River will begin digging. A second machine will launch soon after.
This historic moment marks the start of the first phase of tunnel boring for the Hudson Tunnel Project – the first new rail tunnel under the river in more than 100 years. It is the culmination of more than a decade of planning and nearly three years of construction work.
The two tunnel boring machines launching this fall will bore approximately 1 mile through the hard rock under the Palisades Cliffs in New Jersey to the Hudson County Access Shaft on the border of Weehawken and Hoboken. These two machines will be removed via the access shaft and replaced with a second pair of machines that will build the section of the tunnel under the Hudson River.
The two hard-rock tunnel boring machines are expected to build roughly 30 ft of tunnel per day, including scheduled pauses for maintenance. They will reach the Hudson County Access Shaft approximately one year after launching.
The first phase of tunnel boring is being completed by Schiavone Lane Dragados JV as part of the contract for the Palisades Tunnel Project construction package. The Port Authority of New York and New Jersey (PANYNJ) is managing delivery of this construction package in partnership with GDC.
GDC Chief Executive Officer Tom Prendergast said, “Today we mark the start of boring the first new rail tunnel under the Hudson River since the North River Tunnel went into service in 1910. While we celebrate a start today, this moment also marks the culmination of years of work. We would not be here today without the hundreds of people who have poured countless hours into planning, designing, and building this project. In the days, months, and years ahead, we will continue to build on their hard work to deliver this critical project for the riders who are counting on us today, and the future riders who will use the tunnel for decades to come.”
Francesco Chiappalone, Schiavone Lane Dragados JV Project Manager, said, “I’m incredibly proud of this team. Reaching this stage reflects the hard work of everyone who has helped move the project forward. I want to extend my sincere thanks to the GDC and the Port Authority of New York and New Jersey for their continued support. This level of collaboration between stakeholders and contractors is not something you see every day, and it is exactly this kind of partnership that results in incredible achievements like the one we celebrate today.”
The Hudson Tunnel Project
The Hudson Tunnel Project is an urgent investment in the most heavily traveled stretch of America’s rail network that will improve transportation between New Jersey and New York by building a new two-tube rail tunnel under the Hudson River and rehabilitating the existing North River Tunnel, which has been in continuous service since 1910 and is a leading cause of train delays for hundreds of thousands of daily passengers.
The project is being delivered through 10 construction packages. The first construction package was completed in early 2026. Six additional packages are currently in progress.
Boring the New Tunnel
The new tunnel under the Hudson River will be bored using two sets of two tunnel boring machines – four machines total. Each pair of tunnel boring machines will build the two parallel tunnel tubes simultaneously.
The two machines launching in the coming weeks will bore 5,100 ft through the Palisades Cliffs, from the tunnel portal in North Bergen to the Hudson County Access Shaft on the border of Weehawken and Hoboken.
The machines will be removed via the access shaft, and a second pair of tunnel boring machines optimized for the mixed ground conditions under the Hudson River will be inserted to build the stretch of the tunnel tubes from New Jersey to Manhattan.
Tunneling Using Single Shield Tunnel Boring Machines
The first set of tunnel boring machines are single shield machines, designed for efficient tunneling through hard, dry rock. Each machine’s cutterhead is 28 ft, 8 in. in diameter and the trailing gantry extends roughly 500 ft. Each weighs more than 1,680 tons.
These machines dig through the rock in front of them using a rotating cutterhead fitted with disc cutters that press against the rock face, applying intense pressure that breaks the rock into chips. Buckets behind the cutterhead collect the excavated rock and direct it through a muck ring onto the machine’s conveyor belt, which moves it through the trailing gantry to the back of the machine, where it is hauled out of the tunnel.
As the machine advances, an erector arm is used to place precast concrete segments to form the permanent tunnel lining. Hydraulic thrust jacks push the machine forward, bracing against the edges of the completed tunnel lining.
Years of Work to Reach This Milestone
The start of boring is the culmination of nearly three years of construction work. Starting in late 2023, GDC’s contractors built a bridge supporting a section of Tonnelle Avenue in North Bergen to create space under the highway for the machines’ gantries and excavated the launch box where the tunnel boring machines will start digging.
While this construction was happening, the tunnel boring machines were being manufactured. A single machine is comprised of nearly one hundred complex components, and manufacturing took more than a year.
After factory testing at the end of 2025, the machines were disassembled and shipped to New Jersey. Workers spent months reassembling and testing them on site in preparation for launch.
RELATED: Gateway Development Commission Awards Palisades Tunnel Contract
