Louisiana Railroad Bridge

View an article discussing the 1897-98 reconstruction of this bridge

View an article describing the previous bridge

Located on the south side of the small town of Louisiana, this large through truss swing span carries the former Chicago & Alton across the Mississippi River. A charter was granted to the Louisiana Bridge Company to construct a low clearance drawspan across the Mississippi River between Louisiana, Missouri and rural Pike County, Indiana. The charter stipulated that the drawspans have clear channels of 200 feet, the required on the Mississippi River until this date. The charter was conveyed to the Mississippi River Bridge Company in 1873, which constructed the bridge. The bridge opened in 1873, and provided an important link on the Kansas City line of the Chicago & Alton Railroad.

The first bridge at Louisiana consisted of wrought iron trusses, set onto stone piers. The stone piers were constructed by Saulpaugh & Company, using stone masonry found in the vicinity of the bridge. This company constructed substructures for numerous large railroad bridges throughout the midwest. The substructures were constructed using watertight caissons, sunk to bedrock. From the east end of the bridge, the original bridge would consist of six 160-foot Pratt through truss spans, a 223-foot and a 253-foot Whipple through truss, a 442-foot through truss swing span and a 160-foot Pratt through truss span. All of the through trusses utilized pinned connections, and were designed so that the floorbeams were outside of the truss line. At the time of construction, the swing span was the longest constructed. The swing span utilized inclined upper chords, and a continuous truss, balanced on a swing pier. The swing span and two Whipple spans were fabricated by the Kellogg Bridge Company, while the remaining spans were fabricated by the Keystone Bridge Company.

Soon after construction, the narrow spacing of the piers became a clear problem. Ice flows would push against the piers, resulting in extreme pressure on the bridge. In November 1876, a pier near the east end of the bridge collapsed, resulting in the loss of two of the 160-foot spans. The spans were salvaged and reused at a bridge across Sny Creek east of this bridge, while a larger 320-foot Whipple through truss span would be installed to replace the spans. The Whipple through truss was also fabricated by Kellogg Bridge Company. Later bridges across the Mississippi River would use at least one longer span to help alleviate pressure from ice.

In 1897, the railroad decided to reconstruct the bridge. The Lassig Bridge & Iron Works would be contracted to fabricate new spans, while railroad forces would repair the substructures. The western span (span #9) would be rebuilt with a 158-foot, 6-panel pin-connected Pratt through truss span. The swing span would be reconstructed, using a pair of 6-panel spans of the same design, joined over a swing pier by a large tower. Spans #7 would be rebuilt with a 253-foot, 9-panel pin-connected Parker through truss span, and span #6 would be rebuilt with a 223-foot, 8-panel span of the same design. Spans #5 and #4 would be strengthened using components from old spans #6 and #7. Span #3 would be strengthened, but not rebuilt. The work on the eastern portion of the bridge was completed in 1897, and the work on the swing span and western span completed in 1898. The trusses all utilized a lattice portal, with a date cutout and subdivided heel bracing. This design of portal appears to have been a standard for the C&A. These spans all utilized heavily built up members and pinned connections, typical of bridges in this era. As part of the reconstruction, the substructures were repaired and jacketed with concrete.

In 1905, a pair of 158-foot, 6-panel pin connected Pratt through truss spans were installed to replace the two eastern spans of the bridge. These spans were fabricated by the American Bridge Company at the Detroit plant. These spans both used a double intersection lattice portal bracing, with an A-frame overlaid. In addition, these spans would both use inclined lower chords, heavily constructed members and a deep floor. The stringers of the floor were also inclined, likely to avoid expensive reconstruction to the substructure. In 1945, the center of the bridge would be reconstructed. Span #3 would be replaced with a 319-foot, 12-panel riveted polygonal Warren through truss span, while spans #4 and #5 would be replaced with 6-panel, riveted Warren through truss spans. These spans all utilized A-frame portals, heavy members and built up beams. Since the 1945 construction, this bridge has seen no other significant alterations.

While larger railroads often reconstructed large bridges with one contract, the Chicago & Alton was very resourceful, strengthening several spans to provide a longer life span and reducing bridge costs. This replacement schedule provides for a very unusual combination of trusses, with several designs used on the present bridge. During the late 1890s and early 1900s, the Chicago & Alton invested significant capital into upgrading bridges along the Kansas City line. Due to the clearance and width restrictions, it has been rumored that the bridge will eventually be replaced with a lift span. Overall, the bridge appears to be in fair condition, with some deterioration noted throughout the structure. The author has ranked the bridge as being highly significant, due to the unique design and history.