305th Street Overpass

Recycled Through Girder Overpass over BNSF Railway
Dedham, Carroll County, Iowa

Click the Photo Above to See All Photos of This Bridge!
Name 305th Street Overpass
Built By Chicago, Milwaukee & St. Paul Railway
Contractor Unknown
Currently Owned By BNSF Railway
Length 164 Feet Total, 63 Foot Main Span
Width 1 Traffic Lane
Height Above Ground 20 Feet (Estimated)
Superstructure Type Through Plate Girder and Concrete Stringer
Substructure Type Concrete
Fabrication Date 1898
Erection Date 1913
Original Location Bridge #Z-1040; Rhodes, Iowa
Average Daily Traffic 70 Cars/Day (2009)
Current Status In Use
BNSF Bridge Number 399.03
MILW Bridge Number Z-1282 1/2
Significance Local Significance
Documentation Date October 2018
In 1870, the Sabula, Ackley & Dakota Railroad built a line from Sabula, Iowa to Marion, Iowa; a distance of 87 miles.
This railroad became part of the Chicago, Milwaukee & St. Paul in 1872. The CM&StP (Milwaukee Road) had already constructed a line from Sabula, to Chicago.

By 1881, the Milwaukee Road continued to build west. A new line would be constructed through towns such as Toledo, Huxley, Madrid and Perry.
In 1882, the railroad continued to build west through more towns, such as Coon Rapids, Manning and Neola.
By the end of 1882, the railroad finally reached Council Bluffs.

Although the long mainline was completed, it had many issues. Bridges were not built to standard, curves were an issue; and specifically in the western part of Iowa, grades were atrocious.

Chief Engineer Charles Loweth began to address the problems in 1912. Fresh off of the Pacific Expansion, a veteran team helped redesign two mainlines: Minnesota and Iowa.
The expansion also added the "Pacific" to the title, creating the CMStP&P.
While the Minnesota line presented a fairly straightforward situation, the Iowa line presented more challenges.

The eastern portion of the state was simple, with slight grade and route changes. However, the western portion of the state required many route changes, grade reductions and large bridges.
272 Miles would be completed by 1914, between Green Island, Iowa and Manilla, Iowa. This line featured sleek curves, reduced grades and a top class double track line.
In addition, the remaining track between Manilla and Council Bluffs would also be improved.

However, these expansions quickly were realized as too ambitious. Significant portions of the double track were pulled up. Sections included:
Templeton to Herndon and Newhall to Collins were reduced to single track in 1934. Paralta to Green Island was reduced in 1950, and Madrid to Collins in 1956.

Despite a fairly solid traffic base, the Milwaukee Road was oftentimes in trouble financially. At this point, a mass abandonment was court ordered for the Milwaukee Road. 791 miles in Iowa would be abandoned, including the entire Council Bluffs line.
However, some sections were kept intact. Burlington Northern purchased the line from Council Bluffs to Bayard. This is now the BNSF Bayard Subdivision. BNSF was formed from a merger of the Atchison, Topeka & Santa Fe and Burlington Northern in 1996.
In addition, Chicago & North Western was sold the line from Woodward to Slater, and from Herndon to Perry.
C&NW became part of Union Pacific in 1995. In 2003, the Woodward section was abandoned. In 2004, the Perry to Dawson section was abandoned. The Herndon section was abandoned in 1999.

In addition to the Bayard Subdivision, the Raccoon River Valley Trail and High Trestle Trail also utilize portions of this line.

This uniquely reused girder bridge crosses the former Milwaukee Road mainline near the town of Dedham.
Built in 1913, the bridge features a single through girder span. This span was originally fabricated in 1898 as part of a deck girder viaduct over Clear Creek near Rhodes, Iowa. However, a large number of these types of spans were reused by reconstructing the floor of a girder or pony truss span with new material, such as timber. This particular span was replaced by the present bridge in 1913.
Unlike other known Milwaukee Road overpasses, this girder features a triangular shape, as it was likely a main span of the Rhodes viaduct. However, it would not be unusual for a deck girder to be turned to a through girder, such as a the similar McKnight Road Overpass in Minnesota.
This practice was widely practiced among American railroads, particularly during times of high material cost. Oftentimes, these spans featured approaches of trestle, although this one features a concrete stringer span. However, most overpasses consisted of entirely wooden substructures. This bridge consists of concrete piers supporting the center span, an indication of the quality in construction of the new alignment in 1913.
While many dozens of these such structures were built by the Milwaukee Road, only a few remain today. Most have been replaced due to low sufficiency ratings, as many of these bridges are substandard by modern standards. In addition, most of these bridges have received low sufficiency ratings due to deck issues, as well as inability to adequately inspect, due to a lack of structural plans which would contain details about the quality and size of materials used.
Overall, the bridge appears to be in fair to poor condition, with one large portion of severe deterioration on the south approach pier. However, this bridge was ranked as being "poor" by the National Bridge Inventory in 2009, but has since been deleted from the NBI. With an average daily traffic of 70, rehabilitation work was estimated at approximately $300,000 in 2009.

The author has ranked the bridge as being moderately significant, due to the old age and unique design.
The photo above is an overview.


Source Type


Fabrication Date Milwaukee Road Archives at the Milwaukee Central Library
Erection Date Date stamp
Railroad Line History Source ICC Valuation Information, Compiled by Richard S. Steele

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