| Name | CN Oak Avenue Bridge (Webster City) Illinois Central Railroad Bridge #W354.7 |
| Built By | Illinois Central Railroad |
| Currently Owned By | Canadian National Railway |
| Contractor | W.D. Faus of Webster City, Iowa |
| Length | 20 Feet Total |
| Width | 1 Track (20 Feet) |
| Height Above Ground | 12 Feet 5 Inches |
| Superstructure Design | Concrete Arch |
| Substructure Design | Concrete |
| Date Built | 1904 |
| Traffic Count | 4 Trains/Day (Estimated) |
| Current Status | In Use |
| Illinois Central Railroad Bridge Number | W354.7 |
| Canadian National Railway Bridge Number | 354.7 |
| Significance | Local Significance |
| Documentation Date | 10/4/2017 |
In 1857, the Dubuque and Pacific Railroad (D&P) began construction of a new mainline across central Iowa, which sought to link to the existing Illinois Central Railroad (IC) at Dubuque, Iowa. In May 1857, the first 29 miles were completed between Dubuque and Dyersville, Iowa. In March 1860, the line was completed an additional 49 miles from Dyersville to Jesup, Iowa. In 1860, the D&P was sold to the Dubuque and Sioux City Railroad (D&SC). The D&SC completed an additional 22 miles to Cedar Falls, Iowa in 1861; followed by an additional 43 miles to Iowa Falls, Iowa in 1866. By 1867, the IC had garnered interest in this line, and leased the D&SC. The following year, a bridge across the Mississippi River at Dubuque was completed to link this line and the IC line towards Freeport, Illinois. In August 1869, the Iowa Falls and Sioux City Railroad (IF&SC) completed an additional 49 miles from Iowa Falls to Fort Dodge, Iowa. In October 1870, an additional 135 miles were completed west to the Missouri River at Sioux City, Iowa. The IF&SC was also affiliated with the D&SC and IC; and was fully merged into the D&SC in 1888.
By the late 19th Century, the IC had developed and operated a sprawling railroad network in the central United States. This line served as a principal mainline for the company, connecting Chicago to the Missouri River at Sioux City. In the 20th Century, the IC had become a respected railroad, connecting several major cities in the central United States. The D&SC was fully merged into the IC in 1946. In 1972, the IC merged with the Gulf, Mobile & Ohio Railroad (GM&O) to form the Illinois Central Gulf (ICG). The entire IC system in Iowa, as well as the line between Dubuque and Chicago, were sold to the Chicago Central & Pacific Railroad (CC&P) in 1995. In 1988, the ICG was reorganized as the Illinois Central Railroad (IC). In 1996, the CC&P was repurchased by IC and in 1998, IC was purchased by the Canadian National Railway (CN). Today, CN operates the Dubuque Subdivision between Dubuque and Waterloo, Iowa; the Waterloo Subdivision between Waterloo and Fort Dodge, and the Cherokee Subdivision between Fort Dodge and Sioux City.
Located on the north side of Webster City, this concrete arch bridge carries a former Illinois Central Railroad mainline over Oak Avenue. Prior to the construction of this bridge, it is believed that a grade crossing existed at this location. Between late 1902 and 1904, the IC invested significant capital into the line through Webster City, significantly raising the tracks to eliminate a large sag through the town. The present bridge was completed in early 1904 as part of this project. Currently, the bridge consists of a 20-foot concrete arch span, set onto concrete substructures and constructed at a width of 20 feet. The structure follows a standard IC design, with a "flat-top" arch and stepped wing walls which extend perpendicular from the bridge. The "flat-top" design was used extensively by the IC, as it reduced costs and maximized clearance underneath. Local contractor W.D. Faus constructed the bridge, and it is likely the bridge was designed in-house by the IC. Concrete arches were popular for railroad use, as they were durable and easy to construct. Since the initial construction, the bridge has seen no significant alterations, and remains in regular use. Overall, the bridge appears to be in fair condition, with significant spalling throughout the structure. The author has ranked the bridge as being locally significant, due to the common design.
Citations
| Builder and build date | Illinois Central Railroad Valuation Engineering Field Notes at the National Archives |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |