CPKC US-51 Bridge (Afton)

Name	CPKC US-51 Bridge (Afton) Chicago, Milwaukee, St. Paul & Pacific Railroad Bridge #F-934
Built By	Chicago, Milwaukee, St. Paul & Pacific Railroad
Currently Owned By	Canadian Pacific Kansas City Limited
Superstructure Contractor	Duffin Iron Company of Chicago, Illinois
Substructure Contractor	Unknown
Length	67 Feet Total
Width	1 Track
Height Above Ground	13 Feet 8 Inches
Superstructure Design	Through Plate Girder
Substructure Design	Concrete
Date Built	1938
Traffic Count	1 Train/Day (Estimated)
Current Status	In Use
Chicago, Milwaukee, St. Paul & Pacific Railroad Bridge Number	F-934
Significance	Local Significance
Documentation Date	2/19/2023

In 1880, the Janesville, Beloit and Rockford Railway (JB&R) constructed 14 miles of new railroad, extending from Janesville, Wisconsin to Beloit, Wisconsin. At Beloit, it intersected with an existing railroad line owned by the Chicago, Milwaukee & St. Paul Railway (Milwaukee Road). The following year, the Central Illinois and Wisconsin Railway (CI&W) constructed an additional 15 miles to Rockford. The JB&R was sold to the Milwaukee Road in 1882, and the C&IW was leased to the Milwaukee Road the same year. Via trackage rights over the Chicago, Burlington & Quincy Railroad between Rockford and Davis Junction, this line connected to the Milwaukee Road mainline from Chicago to Omaha. The C&IW was purchased by the Milwaukee Road in 1900.

By the 20th Century, the Milwaukee Road had become a prominent railroad in the United States, operating a network of railroad lines primarily in the Midwest. This line primarily served to connect lines in Wisconsin to the Chicago to Omaha line, as well as serve industries along the Rock River. 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. By 1985, a suitor for the Milwaukee Road was being sought, and the Soo Line Railroad, controlled by Canadian Pacific Railway (CP) purchased the Milwaukee Road in 1986. In 1997, CP would sell the line segment to I&M Rail Link, which was later purchased by the Dakota, Minnesota & Eastern Railroad (DM&E) subsidiary Iowa, Chicago & Eastern Railroad (IC&E). The DM&E/IC&E were purchased by Canadian Pacific in 2008. The CTR trackage was abandoned in 2018. CP merged with Kansas City Southern Railway in 2023 to form CPKC. Today, CPKC operates the Rockford Subdivision between Janesville and Rockford, with a connection to Davis Junction.

Located southeast of Afton, this through plate girder bridge carries a former Chicago, Milwaukee, St. Paul & Pacific Railroad (Milwaukee Road) line over US Highway 51 (Riverside Drive). A previous bridge at this location consisted of a girder bridge, constructed in the early 20th Century. During the 1920s and 1930s, the Wisconsin In the late 1920s and early 1930s, the Wisconsin State Highway Commission began working with various railroad companies to construct grade separations at busy grade crossings. One of the priority projects was constructing a grade separation between this line and US Highway 51, a major north-south route through Wisconsin. Work on the present structure began and was completed in 1938. Currently, the bridge consists of a 67-foot through plate girder span, set onto concrete abutments. The superstructure uses a typical design for the era, with heavy girders, rounded girder ends and a floor composed of parallel I-beams supporting a sheet metal ballast deck. The substructures also use a standard design, with sloped wing walls extending perpendicular to the structure. Duffin Iron Company fabricated the superstructure, and an unknown contractor constructed the abutments. Through plate girder spans were commonly used by railroads, as they were durable and easy to construct. Since the initial construction, the bridge has seen few changes, 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.

Build date	Milwaukee Road Bridge Index, located at the Milwaukee Road Archives at the Milwaukee Public Library
Builder (superstructure)	The Bridgemens Magazine; August 1938
Railroad History Citation	ICC Valuation Information, Compiled by Richard S. Steele

CPKC US-51 Bridge (Afton)

Afton, Rock County, Wisconsin