By 1859, the railroad reached Cedar Rapids. This particular line spurred significant growth in the towns it connected.
In 1860, the Cedar Rapids and Missouri River Railroad was charted to continue construction west. Construction would start the next year.
By 1866, the route reached Boone and by 1867, it reached the Missouri River. This line became instrumental to the growth of Iowa, connecting more towns such as Marshalltown, Boone and Ames.
Both of these routes became a part of the Chicago & North Western Railway in 1884. The C&NW had already built an extensive network of lines throughout Wisconsin and Illinois, and this route provided a new mainline to the Missouri River.
Running across the geographical center of Iowa, the railroad would quickly see a need for upgrading. The first portions of double tracking came in the early 1890s, primary between Clinton and Cedar Rapids. The entire route between these two towns was double tracked by 1893.
A bypass of Cedar Rapids had been built between 1886 and 1887, and was known as the Linn County Railway. This single track cutoff would immediately become a part of the Chicago & North Western Railway.
As traffic continued to grow on the line west of Cedar Rapids, more double tracking projects occurred. Between 1898 and 1902, the entire route to Boone was double tracked, including both the mainline through Cedar Rapids and around Cedar Rapids.
Throughout the 20th century, traffic along the line continued to grow at a steady rate. The entire route, connecting Chicago to the Missouri River became one of the core main lines for the Chicago & North Western. In addition, the route connected to Omaha and the Union Pacific mainline to the Pacific.
By 1995, the Chicago & North Western was a railroad as strong as ever. As a result, it became noticed by other railroads. Despite several failed merger attempts in the 1970s, a Union Pacific purchase of the C&NW finally became reality in 1995.
Union Pacific sought the line to connect Chicago to the West Coast. Currently, Union Pacific operates this route and sends approximately 100 trains per day over it.
The route between Clinton and Boone is now known as the Clinton Subdivision, and is one of the most important rail lines in the United States.
Located between Iowa and Illinois, the Clinton Swing Bridge is one the heaviest used railroad bridges across the Mississippi. The swing span is the largest ever erected, and it was the first electrified swing bridge.
When built, the bridge replaced an older single track bridge. That bridge contained several spans, mostly mismatched Pratt Trusses that would later be relocated to Fall River and Lawrence County, South Dakota.
This bridge currently contains four spans. A deck girder span, a Swing Span, a Parker Through Truss span and a Quadrangular Through Truss Span.
The Parker Through Truss contains 7 panels with riveted connections, the Quadrangular Span has riveted connections and the swing span has a pair of 8-panel leafs with riveted and pin connections.
Unfortunately, it appears that this bridge will be replaced in the early 2020s. In late 2017, some small surveying work began for a new crossing.
As a result, this bridge is almost certainly bound for destruction when the new bridge opens, approximately 100 feet to the south. Construction on a new bridge begins in 2021, and the old crossing will be removed in 2025.
The bridge sits on all masonry substructures. The abutments are extra wide for a third track, which was where the old bridge sat.
During the first decade of the 20th Century, the C&NW engineered several trusses of their own and had them fabricated. The main span of this bridge was one of them.
Historic photo of the previous bridge
While not the oldest bridge across the Mississippi River, the series of three bridges which makes up this crossing is one of the largest. As a result, the author has ranked it as being of high significance, due to the unique design, massive size and old age.
The photo above is an overview. The photo below is sway bracing on the swing span. The bridge is tough to access legally, although it can be done from the riverbank.
|Upstream||Sabula Rail Bridge|
|East Channel||UP Sunfish Slough Bridge|
|Middle Channel||Willow Island Rail Bridge|
|Downstream||Government (Arsenal) Bridge|