The $222 million project to replace the Merchants Bridge that links Missouri and Illinois at downtown St. Louis reached a major milestone Sept. 17, with the first of three new trusses being installed.
Dating back to 1890, the Merchants Bridge serves six Class Is and Amtrak to cross the Mississippi River at St. Louis and is one of the nation’s primary east-west rail corridors serving the nation’s second largest rail hub by car interchange volume and third largest by gross tonnage.
Replacement of the vital rail artery is the bistate St. Louis region’s top freight infrastructure priority, regional officials said in a press release.
Owned by Terminal Railroad Association of St. Louis (TRRA), the Merchants Bridge required reconstruction due to the speed, clearance and load restrictions. The project calls for the removal and replacement of the three river-span trusses, seismically retrofitting the existing river piers, and improving the east approach.
Work began in 2018 and, when completed in early 2023, the new double-track bridge will provide expanded freight- and passenger-rail capacity. This will help move freight faster, cost-effectively and more reliably, and provide an alternative to more congested rail regions like Chicago, officials said.
New spans are being constructed in Wisconsin and shipped to St. Louis for final assembly on the Missouri bank of the Mississippi River. Each new span will be floated into place immediately after the old spans are floated out.
Removal and installation of the three new trusses will require three separate 10-day rail outages, and three separate river channel outages. The first of these outages began Sept. 13 in preparation for the first truss to be moved into position and floated into place on Sept. 17. The other two trusses will be installed in the winter and summer of 2022.
In winter 2020, the Federal Railroad Administration awarded TRRA a $22.45 million Consolidated Rail Infrastructure and Safety Improvements (CRISI) grant toward replacement of the Merchants Bridge. TRRA is providing 90% of the construction costs.
Walsh Construction is the general contractor for the nationally significant Merchants Bridge project, with TranSystems and Burns & McDonnell serving as the project engineers. The steel fabrication is being done by Veritas Steel in Eau Claire, Wisconsin.