Amtrak announced that the main tunneling work for its $6 billion Baltimore & Potomac Tunnel Replacement Program is about to begin, while the company is adjusting the project scope. This project is the largest single infrastructure investment in Amtrak's history.

According to Amtrak's announcement on Tuesday (July 28), project construction is progressing, with the AECOM-Jacobs joint venture serving as the project delivery partner. However, facing challenges posed by construction market conditions, Amtrak and the Federal Railroad Administration have had to take flexible measures to optimize costs and streamline the construction plan.

The adjustments include eliminating an intermediate ventilation facility and its small connecting tunnel to reduce construction impact on the community. This ventilation facility was one of the focal points of complaints in a lawsuit filed by residents of Baltimore's Reservoir Hill neighborhood in 2024. According to CBS News, residents alleged that construction would bring noise pollution, solid waste, and rodent problems.

Additionally, the project team raised the track elevation at the deepest point of the future tunnel by approximately 10 to 22 feet, reducing excavation volume and improving long-term operating conditions. After the adjustment, the maximum depth of the tunnel at affected locations will still remain approximately 150 feet below street level.

Construction Progress

Over the past year, the project team advanced construction of the new Mulberry Street railroad bridge, the first of five bridges to be rebuilt in the overall project.

In March of this year, the construction team achieved a major milestone—breaking through the final rock pillar of a 345-foot-long utility tunnel. This tunnel is expected to be completed in 2027 and will carry water, sewage, communications, and electrical lines beneath the tracks.

In addition, tunnel boring machine manufacturer Herrenknecht has begun manufacturing two tunnel boring machines for the new tunnel excavation. Amtrak stated that the first tunnel boring machine is 50% complete.

The project aims to alleviate congestion on one of the busiest rail corridors in the United States by replacing the aging 1.4-mile track with a new route. The upgrade will construct the Frederick Douglass Tunnel, excavate two electrified tunnels for Amtrak and MARC trains, build a new West Baltimore MARC station, upgrade 10 miles of rail infrastructure, and improve local streets and bridges.

On the contracting front, a joint venture of Clark Construction and Stacy Witbeck was awarded the Construction Manager at Risk (CMAR) contract for the south approach section in 2023, which includes new track and rail infrastructure south of the future tunnel. Another joint venture of Kiewit and J.F. Shea Construction won the CMAR contract for the design and construction of the new tunnel in 2024.

Amtrak President Roger Harris said in the announcement: "Replacing this 153-year-old B&P Tunnel is critical to improving the safety and reliability of the Northeast Corridor, the busiest passenger rail line in the United States. The successful delivery of this project will continue to depend on the support and collaboration of all partners to address and mitigate current and future challenges." Harris also revealed that the tunnel is expected to open in 2036.