MacArthur Bridge Broadway Truss Replacement Design & Construction

The MacArthur Bridge in St. Louis is the country’s fourth busiest rail crossing over the Mississippi River. The MacArthur Bridge Broadway Truss Replacement project increased the acceptable effective rail car width from 13’-4” to 15’ and was completed with minimal train interruptions. CMT was selected for the project based on our experience with accelerated bridge construction methods, phasing work around live tracks, railroad bridge change-outs, and knowledge of railroad safety practices, along with our familiarity with older bridges. 

The project consisted of the design and construction of two single-track bridges over Broadway Avenue. The existing bridge was a 125’ open deck through truss. The replacement bridge is a three-span, ballast deck, deck plate girder, and steel beam span bridge. The foundations and concrete piers were installed beneath the existing bridge under traffic. The bridge was designed for Cooper E80 loading and Seismic Service Level 1. 

The project team worked to overcome several unusual challenges, including employing accelerated construction methods alongside and under live tracks and vehicular traffic. They were also tasked with engineering the removal and demolition of an existing bridge in a constrained site in a downtown urban area. The project was completed within budget and ahead of schedule.