Members of the public and other invited guests were able to witness one of the last milestones in a $222-million project to replace the Merchants Bridge that links Missouri and Illinois near downtown St. Louis over the Mississippi River.

About 130 passengers boarded a riverboat cruise on Aug. 26 to witness history in the making as preparations continued for the third and final bridge truss to be floated into place. The installation is a final phase of the project to replace the rail artery across the river, which is one of the nation’s primary east-west rail corridors serving one of America’s largest rail hubs by car interchange volume and gross tonnage, officials say.

Dating back to the 1890s, the Merchants Bridge serves six Class I railroads and Amtrak. Replacement of the structure has been a regional freight infrastructure priority since 2016.

Owned by Terminal Railroad Association of St. Louis (TRRA), the bridge required reconstruction due to speed, clearance and load restrictions. The overall project includes 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 the bridge is expected to be fully operational by the end of September. The new double-track bridge is intended to provide reliable, resilient and expanded freight and passenger rail capacity, helping move freight faster, cost effectively and more reliably, providing an alternative to more congested rail hubs like Chicago, TRAA officials say.

“Our company has never built a bridge, but today we’re marking a critical milestone in the final steps to deliver our first major bridge infrastructure project—a project that will dramatically improve the flow of both freight and passenger rail traffic through the bi-state St. Louis region,” said Asim Raza, chief legal officer, director of corporate affairs for Terminal Railroad Association of St. Louis.

The new spans were constructed in Wisconsin and shipped to St. Louis for final assembly on the Missouri bank of the Mississippi River. Each was floated into place immediately after the old spans were floated out.

Also, as part of the event, representatives from TRRA and Walsh Construction, the general contractor, provided an overview of the project, its role in the country’s freight network and the steps involved in placing the trusses.

“The Merchants Bridge has been our highest priority project because of its significance in the nation’s freight network,” said Mary Lamie, executive vice president of multimodal enterprises at Bi-State Development, which launched the St. Louis Regional Freightway in 2014. “Its completion will not only strengthen a vital link in the nation’s freight network, it also reaffirms we are on the right path with our approach.”

The freightway’s approach involves coordinating regional freight development efforts, connecting the private and public sectors and advocating for the region’s logistics and selection strengths.

In addition to Walsh, the project team included engineers TranSystems and Burns & McDonnell, both headquartered in Kansas City, Mo. The steel was fabricated by Veritas Steel in Eau Claire, Wis.