Burlington Lift Bridge

View the Historic American Engineering Record documentation for the previous bridge

View an article describing the construction of the previous bridge

Located at Burlington, this massive through truss lift bridge bridge was constructed to replace a 1893-era swing bridge. In the 1850s, numerous railroads were constructing west from Chicago. One significant barrier to expanding further west into Iowa and Missouri was the Mississippi River, which provided for critical steamboat use. By 1855, the Central Military Tract Railroad had constructed a line to East Burlington, now Gulfport. Only two years later, the Burlington & Missouri River Railroad would continue constructing west from Burlington, Iowa. In 1856, the Mississippi and Missouri Railroad Company opened the first railroad bridge across the Mississippi River between Rock Island and Davenport. This low level crossing provided a swing bridge to allow for the passage of steamboats. Only two weeks after opening, a steamboat struck the bridge, beginning a lengthy series of court cases over the right of railroads to construct bridges across the Mississippi River. After the United States Supreme Court ruled in favor for the railroad in Mississippi and Missouri Railroad Company v. Ward (1863), railroads began petitioning congress to authorize additional crossings of the Mississippi River. In 1866, Congress authorized a construction of a bridge at Burlington to connect the two railroad lines. Work on the new bridge began the following year, and the bridge was opened to traffic in July 1868.

The first bridge at this location consisted of a large through truss bridge, utilizing a swing span to accommodate river traffic. The western approach utilized a 175-foot, 15-panel, pin-connected Whipple through truss span, followed by a 200-foot, 16-panel span of the same design. These two spans were set onto a curve, and were constructed wider than the remaining spans. The swing span consisted of a 260-foot, 26-panel, pin-connected Whipple through truss, which had clear openings of 160 feet and was balanced on a center pivot pier. The east approach consisted of six 250-foot, 19-panel spans of the same design, with a lengthy trestle approach on the east end. The entire bridge was set onto stone substructures, which were constructed of limestone from Point Pleasant, Iowa; LeClaire, Iowa and Lemont, Illinois. Two of the piers were set onto caissons sunk to reach bedrock, while the remaining piers were placed on timber piles driven to bedrock. Thomas C. Clarke was the Chief Engineer for the project. Detroit Bridge & Iron Works fabricated the entire superstructure, while the substructures were constructed by an unknown contractor. The truss spans all utilized cast iron upper chords, wrought iron Phoenix Columns for the compression members and iron linkages for the lower chord. A nearly identical bridge at Quincy, Illinois was completed the same year.

Iron bridges were popular in the 1860s and 1870s, as they provided a strong span, capable of spanning large lengths. The use of cast iron top chords was somewhat unusual, as the material is more brittle than wrought iron. In the 1870s, the bridge would be strengthened, and in 1887, the 175-foot span would be filled. It is likely that the span was reused elsewhere on the system. By the late 1880s, the bridge had become too light for traffic, and the railroad began plans to replace the structure. Notable engineer George S. Morison was retained to design a new double track structure, reusing as much of the old piers as possible. Construction began on the new bridge in 1890, and the work was completed by 1893. New Jersey Steel & Iron Company fabricated the superstructure, and the substructure was reconstructed under the direction of the railroad company. To accommodate the double track span, the piers were widened and partially reconstructed. The tops of the piers were reconstructed using a transverse steel girder, which served as a load bearing member. All work was originally carried out under the direction of E.P. Butts. During construction, a stone became loose and fell on Butts, killing him. Work on the bridge was finished under the direction of George A. Lederlee. The reconstruction of the bridge was notable, as the work was significantly cheaper than the initial construction of the bridge. After construction, Morison noted that a new double track bridge on all new substructures likely could have been completed for half the cost of the original structure. Several spans of the previous bridge are known to have been reused at Sylvan Island in Moline and as part of an overpass on Laramie Avenue in Chicago.

The second bridge consisted of a 360-foot, 12-panel, pin-connected Pratt through truss swing span, six 250-foot, 9-panel, pin-connected Whipple through trusses on the east end and two 70-foot deck plate girder spans on the west end. Only the western abutment and pier were constructed new, and the remainder of the substructures were reused from the previous bridge. The Whipple truss spans utilized heavily constructed members and tall lattice portal, typical of bridges designed by Morison. The swing span utilized heavily constructed members, a solid beam for a portal bracing, and a large tower with lattice bracing. The swing span utilized a rim bearing design, where the span is set onto a steel drum, which turns on rollers which are set onto a track. As the bridge was heavily used, it was strengthened and reconstructed a number of times in the 20th Century. Whipple through trusses were initially popular for railroad bridges in the 1860s and 1870s, although the design began to fall out of favor by the early 1890s. These spans could provide longer span lengths, but were more unpredictable overall. It is noteworthy that Morison used a Whipple design here, as Pratt spans of similar lengths had been constructed by this time.

By the early 20th Century, the second bridge had become outdated. After numerous strikes in the 2000s, the Coast Guard ordered the alteration of this bridge. Due to the upstream bend in the river, river traffic had significant difficulties making the turn required to go through the swing span. As a result, BNSF Railway began planning to replace the bridge with a modern structure. Construction began in 2009, and was completed in 2012. The current bridge consists of a 370-foot, 12-panel, bolted Warren through truss vertical lift span, which is positioned slightly east of the original swing span. The eastern approach consists of six 250-foot, 10-panel, bolted Warren through truss spans, and the western approach consists of two deck plate girder spans and concrete modular girder spans. The bridge is set onto new concrete and steel caisson substructures. During construction of the current bridge, the old bridge was floated out span by span and scrapped. The new bridge was constructed by Ames Construction and Walsh Construction Company, and the superstructure was fabricated by an unknown contractor. Portions of the original stone piers were left in place, although they are not being used by the current structure.

Vertical lift spans became the standard for movable spans in the early 20th Century. These types of bridges provided a larger clear channel, and could be lowered and raised quicker than a swing span could turn. The Warren through truss design became popular in the early 20th Century, and has been the most commonly used truss bridge design since. Typical of bridges from this era, it appears the bridge is constructed of weathered steel. This type of steel is better suited for resisting the elements than normal steel. In addition, the bridge utilizes a ballast deck and bolted connections, also typical for modern truss spans. Overall, the bridge appears to be in good condition, with no deterioration noted. The author has ranked the current bridge as being minimally significant, due to the newer age.