ILDOT US-52 Savanna-Sabula Deck-Tied Arch Bridge Replacement


Kraemer replaced this historic steel truss bridge and the realignment of US 52 crossing the Mississippi River between Savanna, IL, and Sabula, IA. The new 11-span bridge comprises three separate portions, two plate girder units consisting of 10 spans totaling 1,908 feet, and the central 546-foot-long tied-arch span, perched 60 feet above the main navigation channel.

Using an alternative to the original design, we erected the tied arch with contractor-designed towers and an onsite cantilevered method of erection. This innovation minimized the impact on marine navigation and recreational boat traffic by eliminating the need to construct in-water falsework adjacent to active shipping lanes by using a multi-staged construction erection plan. Through this method, bridge pieces were transported by a barge, where a crane was used to install the arch pieces in place, supported by cable-stays above. Through these innovations and expertise with complex steel erection, we met the owner’s tight timeline while seamlessly maintaining mobility.