Seneca Lift Bridge

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

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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
In 1881, the Kankakee and Seneca Railroad began construction of a new 42 mile connector route, southwest of Chicago.

By 1882, the railroad would be completed. In Kankakee, it would connect to an Indiana, Illinois and Iowa Railroad line; which would eventually become the New York Central in 1914.
In Seneca, it connected to a Chicago, Rock Island & Pacific line between Chicago and Iowa.

In short, the line served as a bypass to Chicago, allowing traffic from the west to head east or south, while avoiding Chicago.
The line was a poorly built line however. The Illinois River Bridge at Seneca was a weak structure, and would eventually be an expensive replacement.

The railroad was split between Cleveland, Cincinnati, Chicago and St. Louis Railway (Big Four), and the Chicago, Rock Island & Pacific. Each owned half of the beltway.

In addition, by 1900 the Indiana, Illinois and Iowa Railroad would be completed to DePue; nearly 40 miles west. This allowed for a connection to the Rock Island at that point, as well at connections from other railroads.
This new beltline would be better engineered, and in turn see better traffic.

In 1906, The New York Central acquired the Big Four, continuing to operate it as a separate entity.

By 1933, the railroad would be abandoned nearly in entirety. The NYC cut its ties with the railroad, and the Rock Island became the sole owner and operator of the remaining stub.
The only part that remained would be from Seneca, across the Illinois River to a grain terminal.

The Rock Island went belly up in 1980, and the entire system was abandoned.
The Chessie System picked up the line in 1981, and was in turn merged into CSX Transportation in 1986.

CSX is the current operator of this line, a spur off of their New Rock Subdivision, operating between Blue Island and Ottawa.

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


Source Type


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

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