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Seneca Lift Bridge

Pratt Through Truss Lift Bridge over Illinois River
Near Seneca, Grundy County, Illinois

Click the Photo Above to See All Photos of This Bridge!
Name Seneca Lift Bridge
Built By Kankakee and Seneca Railroad
Contractor Unknown
Currently Owned By CSX Transportation
Length 650 Feet Total, 165 Foot Main Span
Width 1 Track
Height Above Ground 20 Feet (Estimated)
Superstructure Type Pratt Through Truss Lift Bridge and Deck Girder
Substructure Type Concrete and Stone Masonry
Date Built Ca. 1900, Rebuilt 1916 and Ca. 1932
Traffic Count 2 Trains/Week (Estimated)
Current Status In Use
Significance Regional Significance
Documentation Date June 2015


Located between Morris and Seneca, this large through truss bridge lift bridge crosses the Illinois River.
It is unknown exactly when the bridge was built, but it is believed that it was constructed in approximately 1900.
Originally, the bridge was constructed with four 6-panel pin connected Pratt Through Trusses. These trusses were set onto stone piers.
In 1916, a train crashed through the southern span of this bridge. As a result, that truss was replaced with a pair of deck girder spans in 1916.
Another alteration was made to the bridge in approximately 1932, when the center of the remaining trusses had a lift span installed. Similar to the situation at Ottawa, Illinois; this lift mechanism was incorporated into the existing trusses.

1910 View of Bridge
1910 View of Bridge; Courtesy Google Books

Today, the bridge serves as a short spur to a Dupont plant on the south bank. The bridge is unique for its alterations that are old enough to be historic. Further alterations included the encasement of the original 1880s piers and abutments with concrete.
Overall, the bridge remains in good condition. The future of the structure is unknown, as it is little used and is a navigation hazard.

The author has ranked this bridge as being regionally significant, due to the unique design.
The photo above is an overview.

Illinois River Railroad Bridges
Upstream Aux Sable Lift Bridge
Downstream (North Canal) Marseilles Nabisco Bridge #1
Downstream (South Canal) Marseilles Nabisco Bridge #3

Citations

Source Type

Source

Build Date Estimated
1916 Reconstruction Date Date of derailment
1932 Reconstruction Date Estimated based on navigation accommodations
Railroad Line History Source ICC Valuation Information, Compiled by Richard S. Steele