UP Sibley Parkway Bridge

Mankato, Blue Earth County, Minnesota

Default pic
Looking east along south track
Looking east along south track
Typical bents and trestle spans
Typical trestle spans, north track
East end, south track
Typical trestle spans
Overview, south track
Main span, south track
Main span, south track
East pier, south track
East pier
Under south track
Looking west along north track
East pier, north track
Looking east along north track
Under north track
West pier, north track
West abutment
West end
Overview, south track
Overview, south track
Typical trestle spans
Looking east along north track
Overview, north track

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Default Pic
Looking east along south track
Looking east along south track
Typical bents and trestle spans
Typical trestle spans, north track
East end, south track
Typical trestle spans
Overview, south track
Main span, south track
Main span, south track
East pier, south track
East pier
Under south track
Looking west along north track
East pier, north track
Looking east along north track
Under north track
West pier, north track
West abutment
West end
Overview, south track
Overview, south track
Typical trestle spans
Looking east along north track
Overview, north track
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Caption:
Name UP Sibley Parkway Bridge
Chicago & North Western Railway Bridge #421
Built By Chicago, St. Paul, Minneapolis & Omaha Railway (South Track)
Chicago & North Western Railway (North Track)
Currently Owned By Union Pacific Railroad/Canadian Pacific Kansas City Limited
Superstructure Contractor Unknown
Length 227 Feet Total, 36 Foot Main Span
Width 2 Tracks
Height Above Ground 13 Feet 0 Inches
Superstructure Design Deck Plate Girder and Timber Pile Trestle (South Track)
Steel Stringer and Timber Pile Trestle (North Track)
Substructure Design Timber Pile and Steel Pile
Date Built 1896 (South Track)
c. 1930 (North Track)
Traffic Count 15 Trains/Day (Estimated)
Current Status In Use
Chicago & North Western Railway Bridge Number 421 (South Track)
M-1603 (North Track)
Union Pacific Railroad Bridge Number 86.84
Significance Local Significance
Documentation Date 8/27/2011
In 1865, the Minnesota Valley Railway Company began construction on a new railroad line between Mendota, Minnesota and St. James, Minnesota. The first 22 miles would be completed between Mendota and Merriam Junction in 1865, followed by 17 more miles to Belle Plaine in 1866, 16 additional miles to Le Sueur in 1867, 12 additional miles to Kasota in 1868, and 22 additional miles to Lake Crystal, Minnesota in 1869. Also in 1869, the Minnesota Valley would complete 5 additional miles from Mendota to St. Paul. In 1870, the Minnesota Valley would be purchased by the St. Paul and Sioux City Railroad (StP&SC). 22 additional miles to St. James would be completed in 1870. The StP&SC completed 58 more miles from St. James to Worthington, Minnesota in 1871; and 64 additional miles to Le Mars, Iowa were completed in 1872. At Le Mars, the route connected to an existing railroad, over which the StP&SC used trackage rights to reach Sioux City.
In 1881, the StP&SC would be sold to the Chicago, St. Paul, Minneapolis & Omaha Railway (CStPM&O), also known as the Omaha Road. The Omaha Road would come under control of the Chicago & North Western Railway (C&NW) the next year. This route became the main line of the Western District of the Omaha Road. The Omaha Road would formally be merged into the C&NW in 1959. The C&NW would be purchased by the Union Pacific in 1995, which still operates the St. Paul to St. James segment as the Mankato Subdivision. The line continues to carry steady traffic.

Located near US Highway 169 in Mankato, this deck girder and steel stringer bridge carries the former Chicago & North Western Railway/Chicago, St. Paul, Minneapolis & Omaha Railway over Sibley Parkway. Little is known about the history of this bridge. In 1896, the Omaha Road realigned their line through Mankato, and constructed a deck girder and timber pile trestle bridge at this location. The C&NW added a similar span to the north side of the bridge at that time. It appears that the bridge was modified in approximately 1930, by replacing the main span of the north track with a steel stringer, and strengthening the main span of the south track with additional girder lines, giving the bridge its current configuration.

Currently, the south track of the bridge consists of a 36-foot deck plate girder span, approached by timber pile trestle spans and supported by timber pile substructures. The north track of the bridge consists of a 36-foot steel stringer span, with the same approaches and substructures. Two different contractors fabricated the steel spans for the superstructure. The south track girder span uses six girder lines, and appears to have been strengthened long ago. Railroads often reused steel spans, as it was an inexpensive way to repair other steel spans which had become too light for traffic. No information is known about the additional girders, although it is likely that they were fabricated in c. 1895 and originally used at an unknown location. Since the last reconstruction, the bridge has seen few changes. The east pier of the south track was replaced by a steel bent in the 2020s. Bridges such as this were commonly used by railroads, as they were easy to construct and economical. Overall, the bridge appears to be in fair to poor condition, with significant deterioration throughout the timber components of the bridge. It is likely that this bridge will be replaced in the coming years. The author has ranked the bridge as being locally significant, due to the common design and unknown history.

Citations

Build date National Bridge Inventory (NBI)
Railroad History Citation ICC Valuation Information, Compiled by Richard S. Steele