Amtrak personnel recently spent a series of consecutive weekends in March remediating damage to the bench wall system in the South Tube of the North River Tunnel that maximized efficiency without interrupting regular train service. The crews were able to take advantage of previously scheduled work that required weekend service outages to replace critical switches near New York Penn Station

Over the course of a 55-hour weekend outage, when more invasive work could be performed without impacting service, crews jackhammered away loose and unstable concrete from the walking surface, poured and set fresh concrete, and retrofit a below-surface splicing chamber into which crews must climb to repair damaged sections of the 12,000-volt feeder cables that run through the tunnel’s bench walls.

Workers have also been injecting grout into the tunnel’s concrete liner to redirect infiltrating ground water and minimize the frequency of infrastructure failures like signal problems and poor track conditions. In 2021, crews took advantage of at least two 55-hour weekend outages when tracks were removed to clean the drain system beneath the track bed.

The work is part of an approximate $150 million investment in a series of interim improvements that Amtrak is making in the more than a century-old tunnel while construction of a new Hudson River Tunnel advances as part of the Gateway Program. The program does not negate the need for an eventual closure of the tubes for comprehensive rehabilitation once a new tunnel is built.

The North River Tunnel Interim Reliability Improvement program is a series of work packages that can be undertaken during existing maintenance windows to target the most problematic sources of train delays and infrastructure failures. Future phases of work involve digital scanning of the track bed and enhanced asset monitoring, which will allow crews to respond more quickly and strategically when problems arise.

Amtrak engineering forces use jackhammers, crowbars and other tools to remove loose and unstable concrete from the North River Tunnel bench wall in preparation for new concrete to be poured as part of ongoing interim reliability improvements.

-via  Press Release