| Name | UP County Road R38 Bridge Chicago & North Western Railway Bridge #574 |
| Built By | Chicago & North Western Railway |
| Currently Owned By | Union Pacific Railroad |
| Superstructure Contractor | Des Moines Steel Company of Des Moines, Iowa |
| Substructure Contractor | Widell Company of Mankato, Minnesota (Original Abutments) Unknown (Concrete Encasement) |
| Length | 45 Feet Total |
| Width | 2 Tracks |
| Height Above Ground | 14 Feet 5 Inches |
| Superstructure Design | Steel Stringer |
| Substructure Design | Stone Masonry and Concrete |
| Date Built | 1941 |
| Traffic Count | 50 Trains/Day (Estimated) |
| Current Status | In Use |
| Chicago & North Western Railway Bridge Number | 574 |
| Union Pacific Railroad Bridge Number | 193.55 |
| Significance | Local Significance |
| Documentation Date | 9/23/2016 |
In 1856, the Chicago, Iowa & Nebraska Rail Road (CI&N) began construction on a new mainline across Iowa, connecting an existing Galena & Chicago Union Railroad (G&CU) line at Fulton, Illinois to the Missouri River. To establish construction, a temporary ferry was installed across the Mississippi River at Clinton in 1856. In 1857, the first 44 miles were completed to Wheatland, Iowa. The following year, 20 miles were completed to Lisbon, Iowa; and in 1859, an addition 17 miles were completed to Cedar Rapids, Iowa. In 1861, the Cedar Rapids & Missouri River Railroad (CR&MR) constructed an additional 41 miles to Chelsea, Iowa; followed by 29 miles to Marshalltown, Iowa in 1862. After pausing in 1863, an additional 29 miles were completed to Nevada, Iowa in 1864, followed by 23 additional miles to Boone, Iowa in 1865. In 1864, both the CI&N and CR&MR were leased by the Chicago & North Western Railway (C&NW). In 1867, the line continued west from Boone, reaching the Missouri River at Council Bluffs, Iowa in 1867.
During the second half of the 19th Century, the C&NW had constructed and acquired a large amount of trackage throughout the Midwest. This line formed a principal mainline for the C&NW, connecting western railroads at Omaha to the railroad hub of Chicago. In 1884, the C&IN and CM&MR were formally acquired by the C&NW. In 1887, the Linn County Railway (LC) constructed a 6-mile cutoff, bypassing Cedar Rapids to the south between Otis, Iowa and Beverly, Iowa. At the end of the year, the LC was formally acquired by the C&NW. During the late 19th Century, several other improvements were made to this line. Between 1890 and 1891, a second track was constructed between Clinton and Lowden, Iowa; and between Libson and the Cedar River bridge. Between 1893 and 1894, a second track was constructed between Lowden and Lisbon. A second track was added to the original mainline through Cedar Rapids in 1898, and between 1898 and 1899, a second track was constructed between the Cedar River bridge and the west side of Marshalltown. In 1901, a second track was completed between Marshalltown and Boone, and new facilities were constructed at Boone. Throughout the 20th Century, the Cedar River bridge remained a gauntlet structure, severely hindering efficient operations.
By the 20th Century, the C&NW was operating an extensive railroad network, which radiated north and west from Chicago. This line served as the backbone of the C&NW, connecting transcontinental freight and passengers at Omaha to Chicago. Known as the Overland Route, this line became one of the most significant railroad routes in the United States. This route saw continuous upgrades during the 20th Century, including significant bridge, rail, tie and signal upgrades. In 1995, the C&NW was purchased by Union Pacific Railroad (UP). In 2002, UP constructed a second track at the Cedar River bridge, eliminating a single track bottleneck in the network. Today, this line remains vital to UP and is still well maintained. The Clinton to Boone segment is known as the Clinton Subdivision, and remains a heavily used double track mainline.
Located on the far west side of Ames, this steel stringer bridge carries a former Chicago & North Western Railway mainline over County Road R38 (500th Avenue/Y Avenue). The first bridge at this location was likely a timber pile trestle, constructed to cross a cattle pass and unnamed ditch. At some point in the 19th Century, a gravel roadway was constructed under the bridge. Between 1898 and 1902, the C&NW undertook a large double tracking project between Cedar Rapids, Iowa and Council Bluffs, Iowa. In 1899, a new 45-foot through plate girder bridge on stone abutments was constructed at this location. This span used a standard design, with square girder ends and a standard floor, and was fabricated by the Lassig Bridge & Iron Works. The abutments also used a standard design, with stepped wing walls extending diagonally from the bridge. During the 1930s and 1940s, the C&NW made a series of upgrades to bridges along this line, replacing or strengthening aging structures. In 1941, the through girder span was replaced by the present steel stringer span, and the stone abutments encased in concrete. It is believed the roadway may have been paved at this time. It is also unclear if the original through girder span was reused elsewhere or if it was scrapped. Currently, the bridge consists of a double track 45-foot steel stringer span, set onto concrete encased stone abutments. The superstructure follows a standard design, with four shallow beams per track, arranged into two sets of two and covered by a ballast deck. The substructure follows a unique design, with tall risers under the span and sloped wing walls, which cover the original stepped wing walls. Stone for the original abutments consisted of a yellow limestone, quarried at Mankato, Minnesota. Des Moines Steel Company fabricated the superstructure, while the Widell Company constructed the stone abutments. An unknown contractor completed the concrete encasement of the substructures. Steel stringer spans 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 to good condition, with no significant deterioration noted. The author has ranked this bridge as being locally significant, due to the common design.
Citations
| Build date and builder (superstructure) | Des Moines Steel Company plaque |
| Builder (substructure) | Mankato Free Press; May 5, 1899 |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |