The project general contractor, Walsh Construction, used four self-propelled mobile transporters to relocate the fully assembled bridge from its assembly site to its final position on the new bridge piers a few hundred feet away.
The 394-foot-long, 43-million-pound bridge will carry Chicago South Shore and South Bend commuter trains and is a key project in the $101 million reconfiguration and grade separation of the intersection of 130th Street and Torrence Avenue, which is part of Chicago Mayor Rahm Emanuel's Building a New Chicago infrastructure program.
The bridge is also a part of CREATE project GS15a, which will reconstruct the intersection to improve traffic flow among all modes of transportation. The project will eliminate the two at-grade crossings of the NS tracks, lower both roads under a new NS freight bridge and the bridge moved into place this weekend, is positioned over the NS tracks.
Daniel Gross, vice president Construction Management Services Director, Great Lakes, with Alfred Benesch & Company, which designed and served as construction management on the bridge, said an option to build the bridge in place was considered, but the construction would take place over live Norfolk Southern tracks, which meant work on the bridge would have to shut down for safety reasons each time a train passed, making assembly of the bridge off site and then moving it into place the better option.
"[The move] is a success," said Gross. "Everything has been planned and pre-tested and we all were very confident this would work."