VIDEO: Merchants Bridge project reaches milestone

New truss is first of three to be preplaced. [Photo courtesy Walsh Construction and Trey Cambern Photography.]

A $222 million project to replace the Merchants Bridge that links Missouri and Illinois at Downtown St. Louis reached a major milestone Friday, September 17, with the first one of three new trusses being installed.

Dating back to 1890, the Merchants Bridge serves six Class I railroads and Amtrak to cross the Mississippi River at St. Louis. It carries one of the primary East-West rail corridors serving the second largest rail hub in the U.S. by car interchange volume and third largest by gross tonnage. Its replacement is the bi-state St. Louis region’s top freight infrastructure priority.

Owned by Terminal Railroad Association of St. Louis (TRRA), the bridge required reconstruction due to speed, clearance and load restrictions. The project includes the removal and replacement of the three river-span trusses, seismically retrofitting the existing river piers, and improving the eastern approach.

Work began in 2018 and, when completed in early 2023, the new double-track bridge will provide expanded freight and passenger rail capacity, providing an alternative to more congested rail regions like Chicago.

A design-bid-build project, reconstruction of the bridge uses innovative project delivery methods intended to improve safety and speed completion while limiting bridge and river traffic outages. New spans are being constructed in Wisconsin and shipped to St. Louis for final assembly on the Missouri bank of the Mississippi River and each 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 on September 13 in preparation for the first truss to be moved into position and floated into place on September 17, a milestone that was witnessed by approximately 200 invited guests and members of the media aboard a riverboat cruise hosted by the St. Louis Regional Freightway. The other two trusses will be installed in the winter and summer of 2022.

Walsh Construction is the general contractor for the project, with TranSystems and Burns & McDonnell serving as the project engineers. The steel fabrication is being done by Veritas Steel in Eau Claire, Wisconsin.