There are more bridge types that make Des Moines one of the most populous bridges in the Midwest. As we will see in this part, truss bridges were just as popular of a bridge design as the arch bridges that were built by James Marsh and company. As many as 30 truss bridges were reported to had been built during the time span between 1870 and 1930 along the Des Moines and Raccoon Rivers as well as other tributaries, including those mentioned in the first two parts of the series. The majority of them featured two or more spans. And while more than half of them were Pratt designs, there were many exceptions to the rule. Already mentioned in part II there was the Post through truss design that had existed at Court Avenue before its replacement in 1917. But like this bridge, the majority of the structures lack the information regarding its history, including the date of construction and the bridge builder. This was in part because of the fact that they were gone prior to the urban renewal period in the 1960s and after 1993. This is not good for many of these structures, like the 18th Avenue Bridge featured some decorative designs on the portal bracings, which were common during the period of bridge construction prior to 1920, when bridge builders could afford to leave their marks with ornaments and builders plaques. After 1920, with the standardization of truss bridges and the letter-shaped portal bracings (A, M and X-frames), these were seldomly used and can rarely be found today when travelling on Iowa’s highways.
Today, eight bridges are known to exist in Des Moines that have a truss design, at least two thirds of the number that had existed prior to 1970. This does not include the CGW Railroad Bridge, which was demolished in its entirety last month. While some of the structures have already been mentioned earlier, the tour of Des Moines’ truss bridges will feature the ones not mentioned. Each one will feature a location, when they were built (and replaced), what they looked like and if there is no concrete information on the bridge builder, some assumptions will be made. As they will mentioned in the Iowa Truss Bridge Book project that is being compiled by the author, any information on the bridges will be useful.
Without further ado, here are the bridges worth mentioning on the tour:
Chicago, Rock Island and Pacific Railroad Bridge at Hartford Avenue: This bridge can be seen from Hartford Avenue on the southeast end of Des Moines. The three-span subdivided Warren through truss bridge with X-frame portal bracings is the fourth bridge to be located at this crossing, for the earliest crossing was dated 1871. It was rebuilt in 1890 and again in 1915 with a four-span through truss bridge with A-frame portal bracings and pinned connections. While it can be assumed that the reconstruction in 1890 and 1915 may have to do with either flooding that damaged the spans or the increase in rail traffic, the current span was built in 1920 by the American Bridge Company and it most probably had to do with the destruction of the 1915 bridge, albeit more research and information is needed to confirm that claim. The bridge is 469 feet long and is owned by Union Pacific Railroad. However, it was part of the Rock Island Railroad with had a line connecting Indianola and Kansas City to the south, going through Des Moines enroute north to Albert Lea and Minneapolis. When the railroad company was liquidated in 1981, the line was acquired by Chicago and Northwestern, which in turn was bought by Union Pacific in 1995. 20 trains a day use this bridge.
18th Street Bridge: As seen in the picture at the very top of the article, this bridge crossed the Raccoon River at what is now Fleur Drive, southeast of the Central Academy. Before its demolition in 1936, the bridge featured four Camelback truss spans and was one of the most ornate bridges in Des Moines, let alone along the Des Moines River. More information is needed as to when the bridge was built (and by who) and why it was demolished. It is known that today’s Fleur Drive Bridge serves four-lane traffic and serves as a key link to Martin Luther King Drive and all points south of downtown Des Moines.
Inter-Urban Trail Bridge: Built in 1902, this bridge spans the Des Moines River south of the Euclid Avenue Bridge. The structure features four spans of Pratt with pinned connections, yet three of the spans feature lattice portal bracings with curved heel bracings, while the fourth and easternmost span features V-laced portal bracings with a 45° angle heel bracing- quite possibly a span that was either brought in or built on-site to replace an earlier span destroyed. This bridge used to serve the Inter-Urban Rail Line, one of eight in Iowa accomodated commuters through the 1950s. This route connected Des Moines with Colfax in Poweshiek County, a length of 23 miles. Service continued until 1949, when the freight railroads took over and people resorted to the car or bus. 33 years later, the railroad line and bridge was abandoned, but the City bought both of them to be converted into a bike trail, which was opened in 1998. With the exception of the replacement of the approach spans in 2012, the bridge today retains its integrity and still serves bike traffic, while providing access to the Neal Smith Bike Trail, which combs the Des Moines River.
Commerce Bridge: Spanning the Raccoon River, this bridge featured four truss spans which included three Camelbacks with Howe Lattice portal bracings with subdivided heels and a Pratt through truss with M-frame portal bracings. The latter was built at a later time, whereas the three Camelbacks were reportedly to had been built by the Clinton Bridge and Iron Works Company, one of many Iowa bridge builders that existed during the period between 1890 and 1930. It is unknown when they were built, let alone rebuilt, but records had it that the bridge was destroyed during the Flood of 1965. The bridge was later removed, and Commerce Street was rerouted to run along the Raccoon. All that remains are the abutments and the rapids where the bridge once stood. They can be seen as 105th Street southwest curves to the south.
Iowa Interstate Railroad Bridge: Spanning the Des Moines River south of the Red Bridge and once part of the Rock Island Railroad, the Iowa Interstate Railroad Bridge was built in 1901 by the American Bridge Company and featured eight spans of pony girders totalling 625 feet. While it used to be a double-tracked bridge, the eastbound track was abandoned and fenced off in the 1980s and today, only one track is used. It replaced a four-span lattice through truss bridge, which had served one-lane of rail traffic and was built 30 years earlier. The future of this bridge is in doubt due to its sparse use, combined with the city’s plans to raise the dikes. Already the Red Bridge was raised four feet and the CGW Railroad Bridge were removed as part of the city flood planning. It would not be surprising that the bridge’s owner, Iowa Interstate Railroad would abandon the bridge altogether, making it the target for scrap metal. But it is unknown if and when that would happen.
SW 63rd Street Bridge: Located over the Raccoon River between Brown’s Woods and Water Works Parks on 63rd Street in West Des Moines, this three-span truss bridge featured two pin-connected Pratt through truss bridges with portal bracings similar to the 5th Street Pedestrian Bridge, located downstream. It is possible that either George E. King or Clinton Bridge and Iron Works (because of the plaque on the portal bracing) had built the original span. Its northernmost span featured a Pratt through truss bridge with riveted connections and A-frame portal bracing. That bridge was most likely brought in to replace one of the original spans that was destroyed either through flooding or an accident. Little information was gathered about the bridge prior to its demolition and replacement in 1964, due to lack of interest in the history of the structure. Had the historic preservation movement started 10-15 years earlier, it would most likely have been one of the first bridges eligible for the National Register of Historic Places. The National Historic Preservation Law was passed in 1966, one year after the replacement of this bridge was open to traffic.
Waterworks Park Bridge: Built in 1922, this Raccoon River crossing is one of the key attractions of Waterworks Park on the south end of Des Moines, as well as the city’s bike trail network. The crossing is 320 feet long and features two 98 foot riveted Pratt pony trusses that used to carry vehicular traffic until its closure in the 1990s. In 1999, the City converted the crossing into a bike trail bridge and has remained in that fashion ever since.
SW Ninth Street Bridge: This Raccoon River crossing is perhaps one of two bridges on this tour that has the least amount of information on its history, despite the fact that it was replaced with the current bridge in 1967. The structure featured three spans of pin-connected Pratt through trusses with Howe lattice portal bracings. Yet that is about it as far as further information is concerned…..
Old Highway 46 Bridge: This is the second of the two bridges that is missing information (including dimensions) and even more detailed photos than what is shown in the link. No information was found in the historic bridge survey conducted in the early 1990s. Located southeast of Des Moines, this multiple-span polygonal through truss bridge was built in 1938 and was removed 60 years later when the Hwy. 65 freeway opened. Other than that, there was no information as to whether a previous structure had existed before that, let alone who the bridge builder was that built the 1938 structure. It is known though that the removal of the bridge came despite protests from farmers, who wanted the bridge open so that they can haul farm equipment across it. Yet because the valley where the bridge was located was flood prone, safety precautions were taken and the bridge was removed. Today, portions of the highway exist on its original path from Avon to the river and from there to Des Moines, terminating at Hwy. 163. Interestingly enough, a railroad bridge located adjacent to the bridge was removed in 1968 after the railroad decided to reroute the line through Indianola enroute to Knoxville. A section of the railroad line exists but makes a dead-end at the power plant located on the north side of the river.
Two Minneapolis and St. Louis Railroad Bridges: Located south of the Iowa Interstate Railroad Bridge over the Des Moines River, the crossings featured two four-span through truss bridges. The northern crossing was a quadrangular through truss bridge with Howe lattice portal bracings. The southern crossing featured Warren through trusses with A-frame portal bracings. Both of them disappeared before 1970.
Ashworth Park Truss Bridge: This is one of three bridges that straddle Walnut Creek carrying Iowa Interstate Railroad through Des Moines (the other two are Pratt pony trusses). The 1897 Warren through truss bridge with Howe lattice portal bracings and riveted connections used to serve dual track rail traffic until the 1990s when it was reduced to only one track. The bridge still serves traffic and can be seen up close from the bike trail while passing through Waterworks Park.
This sums up the tour through Des Moines. The truss bridge portion of the tour is rather the most interesting, but the most challenging if one wants to find information and photos of the structure. As some of the structures will be included in the Iowa Truss Bridge Book project, if you have any information that is useful for the project, or for other people who are interested in bridges in general, you can leave a comment here, or you can contact Jason Smith at the Chronicles at firstname.lastname@example.org. Aside from that, it is hoped that people will have an opportunity to visit the bridges while in Des Moines and listen (or read) the stories involved with each of them, for the bridges span a total of 160 years and three periods, both in terms of materials (wood-iron/steel- concrete) as well as the period of bridge building (trusses-arch-modern bridges). Through the interest in history, you are doing more than just collect stories, you are sharing them with others as well, for there is no such thing as no interest in history. Without history, we are ignorant and a group of people with no identity, no pride and no soul. We take pride in history to ensure we know who we are and bridges are an integral part of our history.
Author’s Note: More info can be obtained by clicking on the links marked in the heading and text. Special thanks to John Marvig for photographing the bridges and allowing usage in this article.