CN/IC Bridge 17-1E
Reconstruction
Client: Canadian National/Illinois Central
Location: Riverdale, Illinois
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Late one summer evening in 2003, a six-track timber trestle in Riverdale, Illinois, caught fire and burned to the ground. The structure carried two Metra Electric District tracks and four Canadian National tracks, and the loss of the bridge dealt a serious blow to both railroads—an estimated 15,000 commuters were left without Metra’s rail service, and the CN Railway was forced to reroute their trains onto other (already busy) lines.
Bowman, Barrett & Associates received a call from the CN/IC railroad on Monday morning, June 23, asking for assistance in reconstructing their four-track structure. This would be a design/build project there was no time for producing conventional design drawings, then hiring a contractor, then fabricating the bridge. When BB&A visited the site on Tuesday, a contractor had already been mobilized, and material for the new bridge was either on its way to the site or was being located. BB&A’s task would be to cobble a bridge together using these available materials.
This project’s unique circumstances made its design a particular challenge. In the early hours of planning for the new bridge, the concept changed frequently, in response to input from the railroad and the contractor. The design that was eventually adopted consisted of steel stringers resting on driven-steel H-Pile piers. The bridge was also shortened from its original 200-foot length to approximately 88 feet. The original north spans were eliminated and replaced by a steel sheet-pile cofferdam structure.
The first track was restored to service on July 2, only 10 days after BB&A was brought on board for the project. The second track was opened on July 4, and the third and fourth on July 9.
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