The Gateway Development Commission said Aug. 20 that the manufacturing of the tunnel boring machines (TBMs) that will build the first mile of the new rail tunnel under the Hudson River is nearing completion.
The procurement, manufacture, and factory assembly of the first and second TBM is 85% and 73% complete, respectively. The commission is overseeing the multi-billion-dollar Gateway Program, the biggest infrastructure project in the country.
Manufacturing of the first boring machines is expected to conclude in the coming weeks, with both TBMs made by November. The boring machines will then be shipped to New Jersey to be reassembled on site. Tunnel boring will start in 2026.
The commission said, “The start of tunnel boring next year will mark the beginning of a new chapter for the Hudson Tunnel Project. After decades of planning and years of preparatory construction, we will be building the much-needed new tunnel under the Hudson River.”
GDC CEO Tom Prendergast said, “While we may use tunnel boring machines instead of picks and shovels to dig tunnels now, the process of building a concrete tube under a river is still a remarkable challenge. The TBMs that we will use for the Hudson Tunnel Project are massive, highly complex machines, and it took nearly two years of construction to prepare for their arrival. Thousands of people across multiple construction teams are working incredibly hard to reach this important milestone on schedule.”
The TBMs are being manufactured at the Herrenknecht AG facility in Schwanau, Germany. After they are tested, they will be disassembled and transported to the Port of Newark via Antwerp, Belgium. The transport process will take about two months. The cost is a component of the procurement process and is part of the Palisades Tunnel contract with Schiavone Dragados Lane, which GDC announced in August 2024.
The TBMs being manufactured will be used to build the first mile of the new rail tunnel under the Hudson River, from the New Jersey tunnel entrance at Tonnelle Avenue in North Bergen to the access shaft in Hudson County.
Two TBMs will bore the two parallel tunnel tubes, installing the concrete tunnel liner behind them as they go. Each machine will build about 30 feet of new tunnel per day. Including days when mining is paused for maintenance, such as replacing disk cutters in the cutterhead that have been worn down by digging, it will take about one year to complete this section of both tubes.
The cutterhead of each TBM measures 28 feet, 8 inches in diameter, and the gantries stretch back roughly 500 feet. Each machine weighs 1,680 tons.
More than 1,000 sensors are placed throughout each machine to monitor the TBM’s position underground, wear and tear on key components, air quality inside the tunnel, and other metrics to ensure safe, efficient tunneling.
This fall, representatives from GDC will travel to the TBM factory to test and accept the machines. Once factory testing is complete, the machines will be shipped to New Jersey. They will be reassembled at the launch point in North Bergen, and tunnel boring will begin in 2026.
