The Dearborn Street Bridge (50 West; 307 North) runs North and South across the main channel of the Chicago River .85 mile from the river mouth. It has the distinction of being one of the youngest Chicago bridges. It opened in October, 1963. It was two years behind schedule for multiple reasons: 1) Constructions snags; 2) disagreements between the city and the contractors; 3) national steel workers strike; 4) Construction of adjacent Marina City. It was rehabbed in 2006.
The bridge description is a metal rivet-connected Pratt Railing Height Truss, movable; double leaf bascule (fixed trunnion; approach spans: metal stringer (multibeam) fixed. The bridge is steel. A unique feature is the presence of only one bridge keeper house.
There is one main span and 4 approach spans. The main span length is 235 feet. The structure length is 341 feet. Roadway width is 56 feet.
Contractors were as follows:
Builder/Contractor Overland Construction Company of Chicago (Bid $2,685,134)
Engineer/ Design City of Chicago
Substructure Contractor States Improvement Company ( Bid $1,162,050)
Electric Contractor Garden City Engineering (Bid $630,992)
This area was the site of multiple prior bridges. The first bridge was built in 1834. It was a movable bridge. It was 300 feet long and 16 feet wide. It was a yellow frame wood hand operated bascule design. It was designed and constructed by Nelson Norton. The city council voted to remove this bridge on July 8, 1839. Irate citizens took matters into their and demolished the bridge. A replacement bridge did not come for years. In the interim, there was a ferry service at this site.
The second bridge at this site was built in 1888. It was an iron, hand operated swing bridge. The construction project involved floating Wells Street Bridge superstructure (built in 1872) to Dearborn Street on scows. This was then mounted on new center piers and foundations. Bridge was designed by Fox and Howard. They were also the superstructure contractor. Substructure contractor was FitzSimons and Connell. Cost was $22,800. At some point in time, the bridge was converted to steam power. In 1897, it was converted from steam to electric. In 1901, Chicago Union Traction replanked the entire roadway. There was a history of multiple collisions involving the bridge. The bridge was removed In 1907.
In 1907, a Scherzer rolling lift bascule bridge was built at this site. The bridge was constructed by the Sanitary District. Superstructure Contractor was George Jackson, Inc. Substructure Contractor was Great paLaces Dredge and Dock Company. Cost was $316,067.72. This bridge was removed in 1959
Bridge Inspection as of 12/2010
Deck Condition Rating Satisfactory 6 out of 9
Superstructure Condition Rating Fair 5 out of 9
Substructure Condition Rating Satisfactory 6 out of 9
Appraisal Functionally Obsolete