Mystery Bridge Nr. 25: The Chaska Swing Bridge

The 1905 engraving on the abutment of the north approach truss span. Photo courtesy of John Marvig

There are many characteristics that made the Twin Cities and its metropolitan area unique during the first half of the 20th Century. This includes historic bridges built by many bridge builders, like Commodore Jones, Alexander Bayne and the Hewett family,  who made their fortunes manufacturing bridges parts to be erected in Minnesota, South Dakota and places to the west.  Many bridges built between 1880 and 1920 made their mark along the Mississippi and Minnesota Rivers as well as over railroads, whether they were stone arch bridges or those made of iron and steel.

The 1896 Chaska Swing Bridge before it was replaced by the Hwy. 41 bridge in 1959 and later in 2011. It was one of two crossing the Minnesota River and one of many bridges built by Gillette and Herzog, a Minneapolis bridge building firm. Photo courtesy of MnDOT.

Between the mouth of the Mississippi River and Mankato, as many as two dozen bridges were constructed between the aforementioned time periods. Yet a quarter of these structures were swing bridges. Consisting of a single span through truss bridge supported on a central pier, a swing bridge turns on the center pier from the river bank towards the middle of the river, allowing ships to pass through.  Bloomington, Savage, Shakopee, Chaska and Belle Plaine had their own swing spans before shipping traffic ceased to exist in the 1930s and were consequentially rendered useless and replaced with fixed span bridges. The Dan Patch Swing Bridge near Savage is the only example of such a swing bridge left along the Minnesota River. Even though the bridge used to serve both rail and vehicular traffic, like the Lindaunis Bridge in Germany, since Canadian Pacific has owned the bridge, the structure is used exclusively for trains.

Dan Patch Swing Bridge near Savage. Photo taken by John Marvig

This mystery bridge article deals with the Chaska Swing Bridge. Located over the Minnesota River between Chaska and Carver, the bridge served as an important railroad link connecting  Chaska and Shakopee between the time it was built in 1871 (rebuilt in 1890 and 1900) and the time it was discontinued by 1972 when its owner the Milwaukee Railroad abandoned the line. The Minnesota Department of Natural Resources purchased it in 1978 to be converted into a bike trail.  This bridge and two other crossings along the line became part of the earlier version of the rail to trail that was supposed to connect Chaska and Shakopee with Bloomington and points to the north. Yet the vision for this riveted steel truss bridge, which featured a Pratt through truss north approach span, was short-lived for despite renovations done on the bridge, the structure was condemned in 1996 when inspectors found that the bridge was sinking and the approach span was shifting. This may have had something to do with the floods in 1993, but there was no concrete evidence to support this claim.  As a safety precaution, on 22 August, 1996, the bridge was imploded. All that remains today are the piers from the approach span and the abutments.  The rest of the bike trail was abandoned after a nearby trestle near Chaska was arsoned on 11 October of that same year. The connection between Chaska and Shakopee was lost until 2011, when the trail was rerouted to the Hwy. 41 Bridge. This coincided with the demolition of the Carver Railroad Bridge, which occurred at the same time. There is hope that this route may be revived in the form of new bridges built at the site of the old railroad bridges in Carver and Chaska, including that of the Swing Bridge.

John Marvig needs your help regarding the bridge. He is currently writing a book about railroad bridges in Minnesota and, he’s looking for information as to who built the structure in 1871 as well as ca. 1900, when the first structure made of iron was replaced by the steel structure, which was in service until it was demolished in 1996. In addition, information on the bridge builder responsible for the north approach span built in 1905 is needed as well.  Exact dates of the construction and the bridge builders, whom the railroad had contracted the project to, would be much useful  to solve the mystery of the Chaska Swing Bridge. If you have any information, please contact him using this e-mail address:

 johnmarvig@chaska.net

You can also view the information that has been collected and used so far by clicking here.  More information on other bridges in the Twin Cities to come soon on the Chronicles.

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