| Name | IAIS Marble Creek Bridge Chicago, Rock Island & Pacific Railroad Bridge #2750 |
| Built By | Chicago, Rock Island & Pacific Railway |
| Currently Owned By | Iowa Interstate Railroad |
| Superstructure Contractor | Unknown |
| Substructure Contractor | Unknown |
| Length | 44 Feet Total |
| Width | 1 Track |
| Height Above Ground | 15 Feet (Estimated) |
| Superstructure Design | Through Plate Girder |
| Substructure Design | Stone Masonry and Concrete |
| Date Built | 1907 |
| Date Replaced | 2021 |
| Traffic Count | 0 Trains/Day (Bridge has been Replaced) |
| Current Status | Replaced by a new bridge |
| Chicago, Rock Island & Pacific Railroad Bridge Number | 2750 |
| Iowa Interstate Railroad Bridge Number | 274.90 |
| Significance | Local Significance |
| Documentation Date | 5/12/2017 |
In 1856, the Mississippi and Missouri Rail Road Company (M&M) constructed 55 miles of new railroad, extending from Davenport, Iowa to Iowa City, Iowa. As part of the work, a wooden bridge was constructed across the Mississippi River, connecting Rock Island, Illinois and Davenport. In 1862, the line was extended an additional 31 miles to Marengo, Iowa; followed by an additional 20 miles to Brooklyn, Iowa in 1863 and 26 miles to Kellogg, Iowa in 1864. In 1866, the M&M and the Chicago and Rock Island Rail Road Company (C&RI) merged to form the Chicago, Rock Island & Pacific Railroad (Rock Island), which constructed an additional 44 miles to Des Moines, Iowa in 1867. In 1869, the line would continue to be extended west towards the Missouri River. At Davenport, this line connected to an existing Rock Island line, which extended east to Chicago, Illinois. In 1880, the Rock Island was reorganized as the Chicago, Rock Island & Pacific Railway. The Rock Island constructed and acquired a large network of railroads, primarily in Iowa during the late 1880s. This line became part of the principal mainline of the Rock Island, and allowed for further development of branch lines throughout central Iowa and eventual expansion west of the Missouri River.
In the late 19th Century, several improvements were made to the line, including revising grades, curves and replacing wooden bridges with stone and iron structures. Due to heavy traffic over this line, portions of the line between Davenport and West Liberty was double tracked in the late 1890s. The Rock Island struggled financially throughout much of its history, experiencing repeated bankruptcies and chronic instability. After World War II, the Rock Island struggled to survive, proposing mergers and deferring maintenance on their routes. The railroad reorganized as the Chicago, Rock Island & Pacific Railroad in 1948. By the mid-1970s, the railroad was in serious decline. The railroad secured loans to eliminate slow orders, acquired new equipment, and attempted to restore profitability. Several sections of this line had fallen into serious disrepair, hampering the Rock Islands ability to maintain efficient operations. In 1978, the railroad came close to profit, but creditors were lobbying for a complete shutdown of the Rock Island. During the fall of 1979, a strike crippled the railroad, and by January of 1980, the entire system was ordered to be shut down and liquidated. Many of the lines and equipment were scrapped. Profitable sections of railroad were prepared for sale.
In November 1981, the Iowa Railroad Company (IARR) began operations over the former Rock Island mainline in western Iowa. In June 1982, the IARR entered into a two-year lease for the entire Rock Island mainline between Bureau, Illinois and Council Bluffs, Iowa; including the Davenport to Des Moines section. In 1983, concerns had grown over the ability of the IARR to provide reliable service to shippers along the line, and several industries came together to form Heartland Rail Corporation, which purchased the line between Bureau and Council Bluffs from the Rock Island trustees. Iowa Interstate Railroad (IAIS) was chosen to operate the line, and began operations in late 1984. After years of thin profit margins, IAIS began making significant financial strides in the 1990s and early 2000s, eventually becoming a major railroad in central Iowa. Increased profit margins and large grants meant IAIS could rebuild deteriorated track, improve bridges and expand operations. Today, IAIS continues to operate the Iowa City Subdivision between Davenport and South Amana, as well as the Newton Subdivision between South Amana and Des Moines.
Located alongside US Highway 6 west of Ladora, this through plate girder bridge once carried a Chicago, Rock Island & Pacific Railroad (Rock Island) mainline over Marble Creek. The first bridge at this location was likely a timber pile trestle, constructed when the line was first built. In approximately 1888, the bridge was rebuilt with a 44-foot deck plate girder span, set onto stone abutments. In 1907, the bridge was again rebuilt with a new through plate girder span, reusing the original stone abutments, which were also modified with concrete extensions. The most recent alteration to the bridge came in approximately 1980, when the entirety of the stone abutments were encased in concrete, giving the bridge its final appearance. The bridge consisted of a 44-foot through plate girder span, set onto a combination of concrete encased stone and concrete abutments. The superstructure followed a standard design, consisting of two shallow plate girders, a standard floor system and square girder ends. The substructure used a modified design, with stepped wing walls and unusual concrete alterations to the tops. An unknown contractor fabricated the superstructure, and an unknown contractor constructed the original stone abutments. It is believed that railroad company forces completed the 1907 alterations to the abutments, and it is unclear if the encasement of the abutments was performed by railroad company forces or by an unknown contractor. Through plate girder spans were popular for railroad use, as they were durable and easy to construct. In November 2021, the bridge was replaced by a larger modern concrete bridge. At the time of replacement, the bridge appeared to be in fair condition, although the superstructure was likely undersized for the waterway and not capable of handling the increasingly heavy trains using this line. The author has ranked this bridge as being locally significant, due to the common design.
Citations
| Build date | Chicago, Rock Island & Pacific Railway Valuation Engineering Field Notes at the National Archives |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |