CSX North Avenue Bridge Progressive Design-Build

Solving a Bridge Clearance Challenge for a Major East Coast Rail Corridor

Project Highlights

• Replace two 27-ft closed-spandrel brick masonry arches with a single-span shallow steel girder bridge to increase clearance over CSX railroad tracks, allowing passage of double-stack trains. Relocate major water and gas utility lines, along with approximately 50 communication and electrical conduits passing through the arches, prior to demolition.
• Utilize a phased construction sequence to reduce impacts to rail, vehicular, pedestrian and bicycle traffic throughout construction, minimizing disruptions to the surrounding community.
• Ensure the protection of existing structures, including Amtrak’s B&P Tunnel, which passes directly beneath CSX’s rails.
• Contribute to the overall improvement of Maryland’s transportation infrastructure, enhancing efficient freight movement to and from the expanding Port of Baltimore.

Challenge

The North Avenue Bridge in Baltimore, MD, consists of seven closed-spandrel brick masonry arches spanning two CSX railroad tracks, two Maryland Transit Administration (MTA) Light Rail lines, one Amtrak line, Jones Falls, and Falls Road. The two arches over the CSX tracks do not provide sufficient clearance for modern, double-stack trains, creating a critical bottleneck that limits CSX’s East Coast rail freight operations.

The site presents unique challenges and constraints:

• The CSX tracks are bounded below by Amtrak’s B&P Tunnel and a historic 98-inch diameter stone and brick culvert, complicating structural work and requiring careful protection of these assets.
• Above, North Avenue serves as a major route for vehicles, buses, pedestrians and cyclists, with traffic that cannot be detoured, demanding precise planning to maintain operations.
• Only the two arches over the CSX rail lines can be modified, and the bridge deck cannot be raised.
• The existing arches support four major water lines, a critical 20-inch diameter gas main, and a network of approximately 50 communications and electrical conduits that must be relocated and supported during construction.
• The MTA Light Rail and CSX rail lines must remain fully operational throughout construction, necessitating detailed coordination with stakeholders and rigorous scheduling.

Solutions

To solve these challenges, Fay and the designer developed innovative strategies tailored to the project’s unique constraints. The solution will replace the two masonry arches with a single-span shallow steel girder bridge, which will provide the required clearance without changing the bridge deck height or lowering the tracks. The new structure will support the existing gas, water, communications and electric utility lines.

• Only the two arches over the CSX rail lines will be demolished and replaced with a shallow steel girder superstructure. The other arches over the MTA Light Rail, Amtrak line, Jones Falls, and Falls Road will remain intact.
• Since this project is a progressive design-build, Fay began with 30% complete owner drawings and collaborated with CSX and the engineering firm to optimize and complete the design.
  • To reduce impacts to rail, vehicle, pedestrian and cyclist traffic, Fay worked with the designers to reduce traffic phasing from three stages to two by temporarily removing the existing concrete jersey median barrier and maintaining traffic on half of the structure at a time.
  • Fay and WRA also proposed shifting Abutment A parallel to the future mainline (west) track alignment, shortening the north side of the bridge replacement by approximately 15 feet. This adjustment reduced costs, minimized the length of utilities requiring temporary support, and decreased the structural steel needed for the bridge girders.
• Fay and the designer developed a comprehensive plan to relocate the critical water, gas, communication and electrical utilities with minimal interruption of services.
• Fay’s team is working closely with CSX, MTA, Amtrak, the City of Baltimore, utility owners and other stakeholders to maintain rail and utility operations while ensuring community needs are met, emphasizing safety and minimal disruption.

---

 

Construction

To meet vertical clearance requirements for double-stack trains, Fay is constructing a new single-span bridge over the CSX tracks while preserving the other existing arches. Key construction activities include:

• Utility Relocations: Fay is carefully removing and replacing four major water lines, a critical 20-inch-diameter gas main, and approximately 50 communication and electrical conduits, ensuring uninterrupted services to city residents and businesses.
• Demolition: Fay will demolish the two arches over the CSX tracks in a controlled manner to protect adjacent infrastructure and minimize impacts.
• New Bridge Construction: A steel girder structure and new bridge deck will be installed to provide the necessary clearance over the CSX tracks while supporting the realigned utilities.
• Phased Construction: Major construction is scheduled in two phases, allowing North Avenue traffic to continue without disruption and maintaining rail, pedestrian and cyclist access throughout the project.

This project not only solves immediate clearance challenges but also supports Baltimore’s broader transportation infrastructure goals, facilitating efficient freight movement and improving connections to the growing Port of Baltimore.
 

Our Team is Ready to Help You

To learn how our team of heavy construction experts can help solve your infrastructure challenge with safe and innovative solutions, contact us.