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| Name | Rockwell Road Bridge |
| Built By | Chicago, Ottawa & Peoria Railway |
| Currently Owned By | City of LaSalle |
| Superstructure Contractor | Decatur Bridge Company of Decatur, Illinois |
| Substructure Contractor | Unknown |
| Length | 157 Feet Total, 107 Foot Main Span |
| Width | 1 Track |
| Height Above Ground | 15 Feet (Estimated) |
| Superstructure Design | Pratt Deck Truss and Steel Stringer |
| Substructure Design | Stone Masonry and Concrete |
| Date Built | 1905(Truss) c. 1990 (Stringer) |
| Traffic Count | 250 Vehicles/Day (Estimated) |
| Current Status | Open to Automobile Traffic |
| Significance | Regional Significance |
| Documentation Date | 6/9/2015 |
In the late 19th Century, electric interurban railways became popular
throughout the United States, particularly in suburban and rural areas.
In rural areas, the interurban represented a reliable form of
transportation, independent of the steam railroads. The Illinois Valley Traction Company constructed 24 miles of interurban railroad, extending from Ottawa, Illinois to Ladd, Illinois in 1902. In 1903, the Ottawa Marseilles & Morris River Railway constructed seven miles between Ottawa and Marseilles. The two railroads were reorganized as the Illinois Valley Railway Company (IVR) in 1904, which constructed 15 additional miles to Princeton in 1905 and 5 miles from Marseilles to Seneca in 1906. An additional four miles to Spring Valley were completed in 1907. In 1907, the IVR was leased to the Chicago, Ottawa & Peoria Railway, which continued to expand the system. In 1909, an extension from Ottawa to Streator was constructed; followed by an extension from Seneca to Morris the following year. By 1912, the line would be completed to Joliet, giving the system a total length of 107 miles.
In 1922, the railroad would become part of the Illinois Traction System (ITC), a large network of interurban lines throughout central Illinois. The former CO&P would become known as the Illinois Valley Division. The ITC sought the railroad as a way to connect the system with Chicago. Proposals were mulled, including extending the Streator Line south to Bloomington. During the 1920s, interurbans throughout the United States became obsolete with the advent of the personal automobile. The Spring Valley to Ladd branch was abandoned in 1923, followed by the Streator Branch in 1928 and the DePue to Princeton section in 1929. The entire system would be shut down and removed in 1934. Today, traces of the system can be found in the form of grading and bridge piers.
Located on the west side of LaSalle, this deck truss bridge once carried the Chicago, Ottawa & Peoria Railway over the Little Vermillion River. A roadway crossing at this location had existed since before 1880. This original structure consisted of a timber truss bridge and was destroyed in a fire in 1880. Another truss bridge is believed to have been constructed to serve roadway use. In 1905, the Chicago, Ottawa & Peoria Railway decided to construct a bridge for both roadway and railroad use at this location. Decatur Bridge Company was contracted to provide steel for a new bridge, and it was determined that the stone substructures could be reused from the previous bridge. The bridge would consist of a Pratt deck truss, approached by a steel girder or stringer span on the east end. It is believed that the west abutment and pier were encased with concrete at this time. In 1916, the Joliet Bridge & Iron Company would construct two 26-foot steel stringer spans and a steel bent to replace the original north approach. After the abandonment of the railroad, the bridge was converted to roadway only use, and remained in this configuration until 1988. In 1988, an ice jam destroyed the east approach of the bridge, and these spans were replaced in approximately 1990, giving the bridge its current configuration.
Currently, the bridge consists of a 107-foot, 7-panel, pin-connected Pratt deck truss span, approached by a 50-foot steel stringer span on the east end. This truss span is lightly built, with laced vertical members. In contrast to traditional railroad deck trusses, this span contains relatively little interior bracing. The bridge utilizes a concrete west abutment and pier, while the east abutment is constructed of stone. Numerous modifications have been made to the truss span. Modifications to the truss include the replacement of the original floorbeams and stringers with new steel. It is possible that this work occurred in approximately 1940, the date given in the National Bridge Inventory for the bridge. Since the abandonment of the railroad, a new concrete deck has been added to the bridge. The Pratt truss design was the preferred design for railroad bridges in the later 19th Century, as the design was simple, economical and easy to construct. Overall, the bridge appears to be in fair condition, with some deterioration noted throughout the bridge. The author has ranked this bridge as being regionally significant, due to the history and reuse of the bridge.
Citations
| Builder and build date | Daily Republican Times; January 4, 1905 |
| Railroad History Citation | Chicago Ottawa & Peoria: The Illinois Valley Railway by Stephen M. Scalzo |