Keeping trains on track & the project on schedule
When Norfolk Southern Corporation contracted with Neel-Schaffer to help build a new railroad bridge over eight busy lanes of I-75 in the bustling Atlanta suburb of Morrow, GA, the Class 1 Railroad had one major request: Do not stop the rail traffic.
“Norfolk Southern was very happy with our work on this project, because they fully understood how tough it really was to complete,” said Mark Jones, PE, the lead engineer for the project.
The three-year, $6 million project involved detouring the operating rail line onto a newly constructed roadway bridge located adjacent to the west side of the existing railroad underpass. Although intended to ultimately only carry roadway traffic, half of this new structure was substantially strengthened in order to accommodate the temporary rail loading, so that both rail and roadway traffic could utilize the structure simultaneously, pending the completion of the new railroad underpass.
Said Jones: “The close proximity of the three bridges, with the need to maintain continuous rail and roadway traffic over the highly congested I-75 at all times, made the construction of this project a real challenge. Extensive shoring, and intricate staging, was essential for the project’s success.”
Neel-Schaffer provided design review and construction engineering and inspection services for the new, 324-foot railroad underpass. The new structure consists of four, steel girder spans supporting a concrete, ballast deck wide enough to accommodate two mainline railroad tracks.
Due to the extremely heavy volume of roadway traffic on a major interstate located so near the metropolitan Atlanta area, it was not possible to erect the new beams spanning the interstate during the day. Neel-Schaffer coordinated with local authorities to periodically interrupt the interstate traffic so that the new beams could be safely set into place between the passage of vehicles under the new structures. The Georgia Department of Transportation would not allow the interstate to be closed prior to 9 p.m., and required that it be fully open to traffic by no later than 5 a.m. Although this provided a nominal eight-hour window for the beam erections, no more than three beams could typically be set in any given night due to the need to periodically allow the interstate traffic to flow, and clear the work site.
“It was certainly a complex project,” said Jones, “but we thoroughly enjoyed solving the many challenges it posed, and are most grateful that Norfolk Southern Corporation had enough confidence in our ability to award us the project. They don’t need us for the easy projects. That is why we always get the tough ones, and that is just the way we prefer it to be.”