Hitherto it has been mostly argued that a new twin-tunnel crossing the River Hudson between New York and New Jersey would have to be built to allow repairs to begin in the existing twin tubes of the North River Tunnel (NRT). However a new tunnel would take at least until 2032 to complete, putting on hold urgent repairs that are required to the existing NRT as its age and the ongoing ravages of Hurricane Sandy continue to take their toll, forcing frequent tunnel closures and associated disruption to Amtrak and NJ Transit rail lines.

LBA’s conceptual study provides an independent third party review of the Hudson Tunnel Project rehabilitation plan and is based on its experience of global best practice. Commissioned in July 2019 by the Gateway Program Development Corporation (GPDC), LBA accessed recent and historical documents, reports, photographs and tunnel drawings. It found the NRT to be suffering from long-term deterioration, leaks, dilapidated tunnel services, track faults and poor drainage. In addition, corrosion and stray-current issues continue to occur as a result of the inundation caused by Hurricane Sandy and the resulting deposition of salts/chlorides.

As a conceptual approach to the problems and to ensure disruptions to train services are minimised, LBA concluded that “regular weeknight and weekend periods of a one-tube outage are feasible, reliable, and safe.” This in-service sequence of repairs would be undertaken in only one of the NRT tubes at any one time and “refurbishment could be undertaken simultaneously in a number of locations in the occupied NRT tube by means of bespoke, highly productive works’ trains or road-rail vehicles.”

Necessary work identified in the LBA report includes repairing the tunnel lining and sealing of leaks; demolishing the bench walls which are failing and deemed unnecessarily high, replacing them with new, lower walkways and cable containments; and replacing the track bed along with other systems-related renewals.

The report stressed that the planning exercise undertaken was conceptual and general in nature and designed to demonstrate the overall feasibility of an in-service refurbishment. However, given the urgency of the required repairs, it firmly rejected the idea of waiting for a new tunnel to be built which, it stated, would put the NRT at risk.

GPDC head Steven Cohen confirmed that innovation and the application of world-best practices for rehabilitating the tunnels would be speedily implemented because it was the right thing to do for customers and economic growth. But he added: “Make no mistake, we need both the new tunnel and a fully working, reliable existing tunnel to have the capacity and reliability our region and nation can depend on for the future.”