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| Name | 305th Street Overpass Chicago, Milwaukee, St. Paul & Pacific Railroad Bridge #Z-1282 1/2 |
| Built By | Chicago, Milwaukee & St. Paul Railway |
| Currently Owned By | BNSF Railway |
| Superstructure Contractor | Unknown |
| Substructure Builder | Chicago, Milwaukee & St. Paul Railway Company Forces |
| Design Engineer | Charles Frederick Loweth |
| Length | 160 Feet Total, 63 Foot Main Span |
| Width | 20 Feet |
| Height Above Ground | 25 Feet (Estimated) |
| Superstructure Design | Through Plate Girder and Concrete Beam |
| Substructure Design | Concrete |
| Date Built | 1914, Using a Span Fabricated 1898 |
| Traffic Count | 110 Vehicles/Day (2024) |
| Current Status | Open to Automobile Traffic |
| Chicago, Milwaukee, St. Paul & Pacific Railroad Bridge Number | Z-1282 1/2 |
| BNSF Railway Bridge Number | 399.03 |
| Significance | Moderate Significance |
| Documentation Date | 10/20/2018 |
In 1870, the Sabula, Ackley & Dakota Rail Road (SA&D) constructed a 21-mile railroad line, extending from the Mississippi River at Sabula, Iowa to Preston, Iowa. The following year, an additional 12 miles were completed to Delmar, Iowa. In 1872, an additional 54 miles were completed to Marion, Iowa. In 1872, the SA&D was conveyed to the Milwaukee & St. Paul Railway (M&StP), which reorganized as the Chicago, Milwaukee & St. Paul Railway (Milwaukee Road) in 1874. In 1882, the Milwaukee Road completed an additional 257 miles between Marion and Council Bluffs, Iowa; completing a mainline from the Mississippi River to the Missouri River. The same year, a bridge across the Mississippi River was completed at Sabula, which connected to the existing Milwaukee Road system in Illinois. By the late 19th Century, the Milwaukee Road had developed a large railroad network throughout the Midwest. This line quickly became a principal mainline for the Milwaukee Road, and allowed for the connection and construction of other branch lines throughout Iowa.
In 1901, a short 12-mile cutoff was completed between Green Island, Iowa and Browns Junction, Iowa; which shortened the distance and provided better grades. The original line was retained as a second track. In the early 20th Century, the Milwaukee Road was aware of the importance of this line, and a massive construction project was planned to modernize the line. Between 1912 and 1915, the line between Green Island and Manilla, Iowa was extensively rebuilt, with a second track constructed and large sections of line relocated. The result was one of the most modern double track lines in Iowa, complete with smooth curves, gentle grades and new bridges. After completion of the project, some short sections of the original line were retained as spurs, which were abandoned by the early 1920s. The Milwaukee Road failed to accurately project the level of traffic over this line, and traffic never reached the threshold that required a double track line. The Milwaukee Road was often in financial trouble, especially after the costly Pacific Extension was completed in 1909. In 1925, the company declared bankruptcy, and reorganized as the Chicago, Milwaukee, St. Paul and Pacific Railroad in 1928. Despite the financial strain, this line remained an important mainline for the Milwaukee Road. Segments between Marion and Covington, Iowa; Newhall, Iowa and Collins, Iowa; and Madrid, Iowa and Templeton, Iowa were reduced to a single track in 1934. The segment between Green Island and Paralta, Iowa was reduced to a single track in 1950; the segment between Paralta and Marion in 1954; the segment between Collins and Madrid, Iowa in 1956 and the segment between Covington and Newhall in 1964. In addition, the original line east of Browns Junction was abandoned in 1950. Financial hardship continued through the 20th Century for the Milwaukee Road, and the railroad again filed bankruptcy in 1977. In 1980, the Milwaukee Road decided to abandon the entire Iowa Division mainline. The segment between Bayard, Iowa and Council Bluffs was sold to Burlington Northern Railroad (BN). Segments between Perry, Iowa and Bayard and between Slater, Iowa and Woodward were sold to the Chicago & North Western Railway (C&NW). A short segment at Marion was sold to the Chicago Central & Pacific Railroad (CC).
In 1985, the segment between Herndon and Bayard was abandoned by the C&NW. In 1995, the C&NW was purchased by Union Pacific Railroad (UP). In 1996, BN merged with the Atchison, Topeka & Santa Fe Railway to form BNSF Railway. The CC was purchased by Illinois Central Railroad (IC) in 1996, and the IC was purchased by Canadian National Railway (CN) in 1998. In 1999, the segment between Dawson, Iowa and Herndon was abandoned by UP. In 2002, most of the segment at Marion was abandoned by CN. Between 2003 and 2004, the remaining portions between Slater and Woodward and between Perry and Dawson were abandoned by UP. Today, BNSF operates the Bayard to Council Bluffs segment as the Bayard Subdivision, and CN still operates a short segment of line in Hiawatha. Linn County has developed large sections around Marion into the Grant Wood Trail. A section west of Rhodes, Iowa has been reused as a trail; and segments between Collins and Slater have been reused as the Heart of Iowa Nature Trail. Much of the line between Slater and Perry has been reused as the High Trestle Trail; and the line between Perry and Herndon has been reused as the Raccoon River Valley Trail. Remaining segments have been abandoned, with much of the right-of-way still intact. In addition, large segments of the original right-of-way that was replaced in the early 20th Century remain intact.
View historic articles discussing the double tracking of this line (digitized by Google)
Located on the east side of Dedham, this through plate girder overpass carries 305th Street over a former Chicago, Milwaukee, St. Paul & Pacific Railroad (Milwaukee Road) mainline, now a BNSF Railway branch line. Originally, the Milwaukee Road mainline turned southwest immediately east of this bridge and did not cross 305th Street in this area. Between 1912 and 1915, the Milwaukee Road reconstructed the mainline across Iowa, improving the alignment and grades, constructing new bridges and adding a second track. In December 1913, construction began on the overpass, and work was completed in March 1914. Currently, the overpass consists of a 63-foot through plate girder span, approached by two 32-foot concrete beam spans on the south end and a 36-foot concrete beam span on the north end. The entire bridge is set onto concrete substructures and runs at a 40-degree skew. The through plate girder span was originally fabricated in 1898 for use as part of a deck plate girder viaduct at Bridge #Z-1040 near Rhodes, Iowa. When that bridge was replaced as part of the same double tracking project, the girders were available for reuse. One span was reused at Bridge #W-72 near Kennebec, South Dakota; another girder was reused at Bridge #Z-1028 which was an overpass carrying Walnut Street at Rhodes, and the third girder was reused at this location.
Upon relocation, the girder was heavily altered with a new floor system to accommodate a wider deck and converted from a deck girder to a through girder. The main span consists of two heavy plate girders with tapered ends and extensive riveting. The floor has been reconstructed with wider floorbeams and a new lower lateral bracing. It is likely that the floorbeams were reused from scrap material from another structure. The stringers consist of several timber beams which are covered by a wooden plank deck. The approach spans use a unique concrete beam design, with several longitudinal concrete beams covered by an integral concrete deck. The piers use a typical design for Milwaukee Road overpasses from this era, with three columns that are flared on the top and connected by a transverse concrete beam. The abutments use a standard rectangular design with short sloped wing walls. In addition, the bridge has a concrete and timber curb throughout and the approaches use an iron pipe railing. An unknown contractor fabricated the girder, while railroad company forces completed the alterations in the field. Typical of concrete bridges along this line, the concrete portions of the bridge were constructed by labor employed by the Milwaukee Road Bridge & Building Department.
Girder spans were popular for railroad use, as they were durable and easy to construct. Railroads often reused steel and iron spans, as it provided a cost effective way to construct bridges without requiring large amounts of new material. Often, when a span was no longer feasible for railroad use, it could be rebuilt and reused for roadway use, which did not have the same loading requirements. In the late 19th and early 20th Century, hundreds of overpasses were constructed throughout the United States by reusing metal railroad bridge spans. As automobiles became larger and heavier in the 20th Century, these spans became outdated often had severe geometric deficiencies. Since the mid-20th Century, a vast majority of reused railroad spans in the United States have been removed or replaced. Often, the metal portions of these bridges were still serviceable, but poor geometry, limited records and deteriorated timber components required the complete replacement of the structure. Because these bridges were typically maintained by the railroad, records are not typically publicly available. As a result, the complete history of the bridge is often unclear, and historic determinations are made using absent or incomplete information. Since the initial construction, the bridge has seen only minor repairs, and continues to carry a fair number of vehicles. Overall, the bridge appears to be in fair condition, with some significant deterioration noted on the concrete portions of the bridge. With repairs to the deck and concrete portions of the bridge, this structure should be capable of carrying roadway traffic for years to come. The author has ranked this bridge as being moderately significant, due to the history of the structure.
Citations
| Build dates and relocation history | Milwaukee Road Drawing Collection, located at the Milwaukee Road Archives at the Milwaukee Public Library |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |