The project involves demolishing the existing tunnel systems down to the concrete liners, repairing the tunnel liner; rebuilding of the bench walls in a modern, high-low configuration with new cable conduits; switching from ballasted track to a modern, direct fixation track system; installing new fire and smoke detection systems; and replacing signals, traction power, standpipe, and drainage systems, according to Amtrak’s project website.

Last year, decommissioning Line 2 included removing approximately 24,000 linear ft of running rail, 12,000 linear ft of electrified third rail, 8,000 railroad ties, and 8,000 cu yd of ballast. Crews then demolished some 24,000 linear ft of bench wall using robotic demolition machines at six locations, supported by hydraulic rock splitters. 

Crews demolishing the tunnel's old benchwalls in October, 2025.  Photo by Jeff Rubenstone/ENR

By early this year, the team placed more than 16,000 linear ft of new benchwall across 41 pour days. “The benchwall and track are completed and the state of good repair [work] is done,” says Youssef Dehne, Amtrak project manager. “As for systems installation, overall we’re in the range of 80% complete.”

In its approximately $637-million contract, the joint venture proposed adding a 60-ft-deep access shaft on 32nd Street in Manhattan in addition to the tunnel access in Queens, says Lek Boonpektrakul, project executive with Skanska. “On the west side of the tunnel near Penn Station, there was no way to reach the construction site,” he notes. “We needed another entry point, especially for emergencies.”

Even with the additional access, "it was a logistics challenge," says Dehne. "Delivery of materials or tools, in and out—it took a lot."

The team used the 32nd Street shaft to install two temporary ventilation fans at the bottom, which supplied air and removed the need for ductwork in the tunnel ceiling, Boonpektrakul adds. This avoided conflicts with the permanent systems and helped keep the construction schedule on track.

“At the track level of the Western Portal, where we built the 32nd Street shaft, we installed a 20-ft-high barricade to keep us separated from the live track (Line 1),” he adds. “Early in the project, we used S3 cable relocation outages as opportunities to build the barricade. This took a lot of coordination from design to construction, and we relied heavily on Amtrak’s support to complete the shaft.”

Amtrak in turn relied on support from various city agencies. “We explained the need for the shaft, and the city agencies approved the permits faster than I’d have thought,” says Dehne. Moreover, Amtrak worked with Long Island Rail Road and New Jersey Transit, plus local stakeholders such as a nearby hospital, adds Derick Hallahan, Amtrak assistant vice president for major programs, tunnels and systems.

Before the team took Line 2 out of service, it had to reroute a portion of electric feeder cables located to the adjacent Line 2, says Patricia Mohiuddin, vice president and division manager with E-J Electric. “Several outages were required over weekends to clear a pathway to put new cable in and splice it to the existing feeder in middle of the tunnel,” she says. “But the condition of the cable we planned to splice was deteriorated, so we had to pull an extra 400-ft section to the next chamber to get to the existing cable.” State of good repair needs increased from the original estimated 200 ft to some 3,000 ft, but the team is still within schedule and budget.

The joint venture also worked with Amtrak improve safety by extending the project limits at the east end by several hundred feet to eliminate any risk of contact with overhead lines, she adds. “On the west side, we built a box around the catenary wires. These steps made the work area safer and more efficient.” 

The team divided the tunnel into three sections and used color-coded maps to track which trades would be in which section during each shift to maximize production. "As conditions changed, coordination changed,” says Mohiuddin. “Every day the team gets together and coordinates the next few shifts ahead." 

Boonpektrakul notes that the concrete benchwall near the tunnel portals on either end was in better shape than at the midpoint, making demolition tougher. While the original tunnel design incorporated two “high” benchwalls, the rehabbed tunnels will feature a “high” benchwall on one side of the tunnel and a “low” benchwall on the other side, according to Amtrak. The new “low” benchwall will provide improved access beneath trains in the event of a delay or maintenance issue that must be resolved underneath the train. 

“Beyond standard tunnel lighting, there are new CCTV cameras, blue light telephones, speakers, radio systems, liner heat detection, very early smoke detection apparatus, and emergency egress pathfinding system,” says Mohiuddin.

Line 2 is scheduled to be back online this summer, and crews will begin work on the planned 13-month rehab of Line 1 in the fall. ‘We have slightly less scope of work in Line,” says Dehne. “Line 2 is about 60% of the total scope.”

While the work components are basically the same, “We can use what we learned in Phase 1 to make the tunnel safer and improve logistics,” says Boonpektrakul. “For example, the team will use different demolition equipment. We will also survey the tunnel’s current condition and look for any issues early in Phase 2.”