Could the L-train plan work for the Hudson River tunnel?


Ever since news broke in January that the long-dreaded, 18-month L-Train shutdown was cancelled, experts have been asking if a similar strategy to fix the Canarsie Tunnel could be applied to Amtrak’s North River Tunnel under the Hudson River.

At 110-years-old, the two tubes in the trans-Hudson Tunnel used by NJ Transit and Amtrak are in desperate need of a complete overhaul. Patchwork fixes since Superstorm Sandy have not been enough to eliminate frequent delays. The closure of just one of the two tubes would have terrible impacts on the regional economy, traffic, safety, and the environment.

So even as an independent team of consultants examines the feasibility of the new proposal for the L Train, it is worth asking if the Gateway program could be revised in a similar manner.

There are two significant challenges to applying this fix to the North River Tunnel:

  1. The cables powering the Canarsie subway tunnel deliver much lower voltage than those in the North River Tunnel. The cables used by Amtrak carry more than 12,000 volts compared to just 625 volts for the subway. They are larger, heavier, and require more protection. Consultants have said that it seems unlikely that a “racking system” that lays the cables along the walls of the tunnels would be safe in the Hudson River tunnel.Other tunnels that are wider in diameter and built as new construction are apples and oranges comparisons in their technical considerations and project scope.
  2. Amtrak’s Hudson River Tunnel contains ballasted track: crushed stone cradling the railroad ties on top of the concrete casing of the tunnel walls. This is an older style of track bed construction that needs to be replaced in order to improve drainage issues that lead to problems in the track and signal systems, leading to train delays. The Canarsie tunnel uses a direct fixation approach — the track is connected directly to the concrete casing — which is a more modern and more stable approach. The track bed in the Canarsie tunnel is easier to replace in segments, but in the Hudson tunnel there is no way to rip out parts of the track at night or over the weekend and have it working again for the next weekday morning.

Additionally, as RPA has documented elsewhere, the region is already suffering from lack of capacity in the two existing rail tubes at peak periods. RPA projects that demand for trans-Hudson travel could grow by as many as 150,000 additional commuters daily in the next generation. Without new capacity under the Hudson River, either these jobs will not come to the region, or they will not be accessible to New Jersey residents.

The only responsible course of action is to build the Gateway project now before it’s too late. Learn more about how to get involved at buildgateway.org.

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