IAIS McPherson Avenue Bridge


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Name IAIS McPherson Avenue Bridge
Chicago Great Western Railway Bridge #500.25
Built By Chicago Great Western Railway
Currently Owned By Iowa Interstate Railroad
Superstructure Contractor American Bridge Company of New York
Substructure Contractor Zitterell-Mills Company of Webster City, Iowa
Length 339 Feet Total, 61 Foot Largest Span
Width 1 Track
Height Above Ground 60 Feet (Estimated)
Superstructure Design Deck Plate Girder, Steel Stringer and Concrete Modular Girder
Substructure Design Concrete, Steel Tower and Steel Pile
Date Built 1924 (South Span)
1937 (North Span and Steel Stringers)
2013 (Approaches and Jump Spans)
Traffic Count 3 Trains/Day (Estimated)
Current Status In Use
Chicago Great Western Railway Bridge Number 500.25 (Old #D-194)
Iowa Interstate Railroad Bridge Number 484.45
Significance Moderate Significance
Documentation Date 1/27/2017

In 1886, the Mason City & Fort Dodge Railroad (MC&FD) constructed 73 miles of new railroad, extending from Mason City, Iowa to Fort Dodge, Iowa.  In 1901, the MC&FD was leased by the Chicago Great Western Railway (CGW).  Between 1902 and 1903, the MC&FD constructed 133 miles of new railroad, extending from Fort Dodge, Iowa to Council Bluffs, Iowa.  The CGW would be reorganized as the Chicago Great Western Railroad in 1909, and maintained a lease of the MC&FD property.  The CGW had acquired and constructed a modest railroad network throughout Illinois, Iowa, Minnesota and Missouri; connecting major cities in these states.  The CGW was one of the smaller railroads in the area, and was late to develop lines.  As a result, the railroad never saw the fortunes of other railroads in the area.  This line served as a principal mainline for the CGW, serving agricultural industries and providing a connection to terminals at Omaha, Nebraska.  In the early 20th Century, the CGW was often surviving on razor-thin profit margins.  In 1940, the CGW entered bankruptcy, and was again reorganized as the Chicago Great Western Railway.  At this time, the MC&FD was formally merged into the CGW.  After the bankruptcy, the CGW became an innovative railroad, pioneering intermodal service and becoming one of the first railroads to completely switch to diesel locomotives.  A capital improvement program was launched in 1949, which sought to rebuild and rehabilitate deteriorated infrastructure.  

In 1953, the Chicago, Rock Island & Pacific Railroad (Rock Island) began using a segment between McClelland, Iowa and Council Bluffs.  In 1968, the CGW was purchased by the Chicago & North Western Railway (C&NW). The C&NW already owned a better constructed route serving Council Bluffs, and much of this line became excess for the C&NW.  In 1971, a section of the line between Harlan and Council Bluffs was abandoned, and the McClelland to Council Bluffs segment sold to the Rock Island.  An additional segment between Somers and Carroll was abandoned in 1977, followed by a section between Manning and Harlan in 1981 and a section between Carroll and Manning in 1983.  After the Rock Island went bankrupt in 1980, the McClelland to Council Bluffs segment became part of the Iowa Interstate Railroad (IAIS).  In 1995, the C&NW was purchased by Union Pacific Railroad (UP).  UP abandoned a section of the line between Thornton and Belmond in 2000, followed by a section between Mason City and Thornton in 2007 and a section between Roelyn and Somers in 2008.  Today, UP operates the Fort Dodge Subdivision between Belmond and Roelyn and IAIS operates a short segment of the Council Bluffs Subdivision between McClelland and Council Blufffs.  The segment between Mason City and Belmond was acquired for trail use, and portions of the right-of-way have been reused as part of the Prairie Land Trail.  The remainder of the line has largely reverted to adjacent landowners, and has been converted to farm fields.


Located near Interstate 80 on the east side of Council Bluffs, this large deck plate girder viaduct carries a former Chicago Great Western Railway mainline over McPherson Avenue and Little Mosquito Creek. The first bridge at this location consisted of a large timber frame trestle, constructed when the line was first built. In addition, this bridge had two small steel stringer bridges over the roadway and creek. In 1924, the span over McPherson Avenue was replaced by a deck plate girder span, set onto timber pile piers. Between late 1936 and early 1937, the bridge was reconstructed with a second deck girder span, steel stringer spans and steel towers, retaining timber pile trestle approaches. The most recent alteration to the bridge came in 2013, when the timber pile trestle approaches were replaced by concrete modular girder spans, giving the bridge its present configuration. Currently, the bridge consists of a 60-foot deck plate girder span over McPherson Avenue and a 61-foot deck plate girder span over the waterway, set onto two steel towers and a steel south bent. The north tower uses a 27-foot steel stringer span, while the south tower uses a 17-foot steel stringer span. Both approaches consist of three modular concrete girder spans, with a short steel stringer jump span between the main spans and approaches. The main portion of the bridge is set onto concrete footings, while the approaches are set onto steel bents with concrete caps.

The deck girder spans use a standard design, with two heavy plate girders per span. The steel stringers also use a standard design, with two heavy I-beams per span. The towers are constructed out of a combination of solid beams and built-up beams. The footings consist of standard square pedestals with additional concrete beams to stabilize the embankments. The approaches use a standard design, with a hollow interior and two beams per span. American Bridge Company fabricated the steel spans, while Zitterell-Mills Construction Company constructed the substructures and erected the bridge. Deck plate girder spans were popular for railroad use, as they were durable and easy to construct. Viaducts like this bridge were popular for tall and long bridges like this, as they were the most economical design. Since the 2013 reconstruction, 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 the bridge as being moderately significant, due to the size.


Citations

Build dates Chicago Great Western Railway Authority For Expenditure at the Chicago & North Western Railway Historical Society Archives
Builder (south span superstructure) Missing American Bridge Company plaque
Builder (north span superstructure) The Bridgemens Magazine; December 1936
Builder (substructure) The Daily Nompareil; January 6, 1937
Railroad History Citation ICC Valuation Information, Compiled by Richard S. Steele

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