Planning, coordination and innovation were hallmarks of this $80-million, 11-span Mississippi River crossing. The alignment, which included a 350-ft U.S. Coast Guard-approved shift of the river’s main navigation channel, also required measures to protect a national wildlife refuge and safeguard as many as 60 trains daily on two underlying mainline tracks.

To build the 546-ft-long, 60-ft-high tied-arch span, Kraemer designed towers and a cantilevered erection method that eliminated the need for in-water falsework adjacent to active shipping lanes. Bridge pieces were transported by barge and installed by crane. The project also featured Illinois’ first use of drilled shaft foundations and waterline footings for the river piers—another cost-saving method that eliminated the risks of installing large, deep cofferdams. 

The Mississippi River was largely unforgiving to construction progress. Numerous high-water events from rain and snow repeatedly threatened to delay critical construction activities. 

Normal river pool conditions were observed less than 10 times throughout the two-year project. The Kraemer-led team compensated by staying abreast of upstream weather conditions and working extended hours until it was safe to dive. The project also involved the construction of a 1,565-ft-long soldier pile wall with concrete cladding at the eastern end of the structure. Wall height ranged from 12 to 29 ft.