The National Gateway Initiative Phase 2 was a three-year, expansive transportation achievement that utilized the Progressive Design-Build model to attain vertical clearance for double-stacked rail cars throughout CSX’s network, connecting East Coast port cities with the American heartland. The contractor-led design-build team ultimately cleared eleven obstructions at nine sites across Maryland, Virginia, West Virginia, and Washington DC to deliver an incredibly complex infrastructure update.
While establishing and executing the scope of work may seem simple – find obstructions along CSX tracks and clear them – the actual process was a dynamic and iterative effort of the design-build team to identify the most effective way to clear overhead obstructions along the CSX rail lines. CSX and their partners spent years planning, coordinating and negotiating to establish a defined picture of the nine project sites that would require a concerted construction effort. The design solutions, tailored to each site, spanned four bridge modifications or replacements, one tunnel modification, and four track lowerings:
o Germantown Pedestrian Bridge Raise, Germantown, MD: replacement of a three-span, reinforced concrete bridge with a prefabricated steel truss, and construction of new retaining walls for the pedestrian walkways
o Jessup Road Bridge Raise, Jessup, MD: 11-inch bridge raise using a hydraulic jacking system and lattice of customized steel, as well as extensive bridge modification and improvement
o Point of Rocks Tunnel and Catoctin Tunnel, Jefferson, MD: Track lowering through two consecutive, historic tunnels along the famous C&O canal, originally constructed in 1902
o Washington Grove Bridge Replacement, Gaithersburg, MD: demolition and replacement of the existing superstructure, followed by the raising of the existing concrete abutments, wingwalls, and wooden piers, finished with the new superstructure installation with arching steel girders, glued-laminated wood decking, and guardrail
o Railroad Avenue Bridge Removal, Jefferson, MD: demolition and removal of a three-span, single lane monolithic concrete bridge crossing duel main line railroad tracks
o Harper’s Ferry Tunnel Modification, Harper’s Ferry, WV: modification of the historic tunnel, located adjacent to both the C&O and Appalachian Trails and five National Parks
o Shenandoah Junction Track Lowering, Shenandoah Junction, WV: reconstruction of a Class 1 freight rail corridor, including full depth track construction, new track profiles and horizontal alignments for the CSX tracks, as well as a bridge abutment buttress wall and re-profiling of an existing state roadway
o Winchester and Western Bridge, Martinsburg, WV: bridge jacking over CSX tracks, conversion of the Tuscarora Creek bridge to a ballast bridge deck, raising the railroad to a new profile and grade, and building a sheet pile and precast lagging retaining wall to support the raised deck
o DC Track Lowering, L’Enfant Plaza in Washington DC: three-foot track lowering for which the team maintained a standard ballast section on adjacent operating tracks, completed in five phases to allow two tracks to operate at all times.
CSX required the ability to transport taller rail cars along their tracks as they travel through tunnels, under bridges, and past other overhead obstructions. The design-build team’s goal was to provide this clearance at the ideal intersection of schedule efficiency, low cost, and certainty of outcome. This goal, made possible through the progressive design-build model, required trust, transparency, and expertise to address a multitude of constraints and conditions at each of the individual obstruction sites. The overhead obstructions belonged to multiple stakeholders, including both private and public entities. Completing the work required the capabilities to navigate permitting agency requirements, stakeholder interests, and site logistics and access, all while minimizing impacts to CSX's ongoing rail traffic. Ultimately, NGI II served as a unique example of progressive design-build infrastructure improvement across multiple state lines. The nature of the project necessitated an innovative, highly flexible, and adaptive team with a cohesive structure of trust and collaboration – and that’s what the design-build team delivered.
The Harper’s Ferry Tunnel serves as one example of the design-build team’s efforts to maximize efficiency and minimize impact. The team coordinated with CSX to complete work during total track outages on Friday and Saturday nights. Originally, the project team used the expected productivity of 12-hour shifts to schedule completion in 12 months. Knowing that 12-hour outages placed a significant constraint on CSX operations, the team found a way to shorten the timeline. Clark coordinated with the specialty tunnel subcontractor and tunnel engineer to increase tunnel liner productivity. The team truncated the timeline, completing work in just eight months to eliminate closures for CSX four months ahead of schedule.
Each site presented the team with the opportunity to service the surrounding community, whether it was cleaning up the property, improving drainage and safety features, or refurbishing existing public facilities. In historic Washington Grove, the community opposed replacing the bridge with a modern-looking structure. To retain the look of the existing bridge, the team produced a design using cambered steel beams and wood laminated decking and guardrails installed on a vertical curve. The steel design was critical to retaining a historic aesthetic, and increasing the vertical clearance.
The initiative’s completion also presented implications for economic gains across the country. Changes in the transportation marketplace allow railroads to capture additional business along routes. The ability to operate double-stack trains allows for twice as many containers for a given train length, reducing shipping costs per container. CSX connected Mid-Atlantic ports with markets in the Midwest and beyond.