Glasgow Railroad Bridge

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View an article describing the career of design engineer August Ziesing

Located along Missouri Route 240 in the small town of Glasgow, this large bridge once carried the Chicago & Alton across the Missouri River. As this railroad line was extended towards Kansas City, a bridge across the Missouri River would be required. A high level bridge would be authorized at Glasgow, requiring large spans. The railroad hired General William Sooy Smith to design a large truss bridge. Sooy Smith recommended the use Hay Steel, at the time a revolutionary new material developed by A.F. Hay of Burlington, Iowa. Construction on the bridge began in early 1878, and the new bridge was completed by 1879. The first bridge consisted of three 315-foot, 17-panel, pin connected Whipple through trusses, approached by two 314-foot Whipple deck truss spans of the same design on the west. The east approach would consist of two 140-foot, 9-panel, pin connected Pratt deck truss spans, approached by seven 30-foot deck plate girder spans. The west approach would consist of a 143-foot, 10-panel, pin-connected Pratt deck truss, and 17 30-foot deck plate girder spans. Large stone piers would be constructed for the bridge, and the deck girder approaches would be set onto steel towers, with alternating girders making up the tower spans. The main piers utilized a unique decorative design, with a forked shape extending upwards from the river level. The stone for the piers was made of a poor grade Missouri limestone.

The first bridge at Glasgow is believed to have been the first all steel railroad bridge ever constructed. Sooysmith & Company, owned by William Sooy Smith would complete the stonework on the bridge. The steel for the spans was made at the Edger Thomson Bessemer Steel Works, and was rolled into shape by the Husse, Howe & Company. The spans were fabricated and erected by the American Bridge Company of Chicago. Soon after completion, the main piers began to fail. Vibrations from the bridge caused stress on the slender columns, and some piers would need to be reconstructed. At some point during the 1880s, piers #3 and #4 were rebuilt from the water level, and steel towers installed on the piers. By the end of the 19th Century, the deteriorated piers and light truss spans had become unsuitable for traffic demands of this line. Several options were considered by C&A officials, including constructing a new bridge alongside the existing bridge. By 1899, at had been decided to replace the bridge at the current location, reusing what structure was salvageable. One of the main spans would be made one panel length longer, to account for replacing piers #5, #6 and #7. Piers #3 and #4 would be reused in the new bridge. It was also decided to shorten the 508-foot west approach by filling a large portion of it with embankment. The replacement of this bridge coincided with a larger bridge improvement program for the C&A, which included replacing many of the major structures on the Kansas City line.

In August 1899, contracts were let to the Engineering Contract Company for construction of the substructure, and to the Lassig Bridge & Iron Works for fabrication and erection of the superstructure. The new bridge would be designed by August Ziesing, a prominent Chicago-based bridge engineer. Ziesing had graduated from University of Illinois in 1878, and had spent five years as bridge engineer with the Pennsylvania Railroad. In 1883, Ziesing returned to Chicago, where he would become Manager and Chief Engineer of the Lassig Bridge & Iron Works, leaving the position to start a private practice in 1897. During this time, Lassig Bridge & Iron Works would become among the most prominent bridge builders in the United States, providing significant bridge material for railroads in the Midwest and Western United States. When the Lassig Bridge & Iron Works was consolidated into American Bridge Company in 1900, Ziesing was appointed Western Manager and Vice President at the recommendation of many bridge engineers. Ziesing would become president of the American Bridge Company in 1905, and oversaw the companies rise to prominence, retiring from the position in 1927. Ziesing continued his involvement with the company until his death in 1942.

Stone for the new piers would be cut by Bedford Stone Company, and the piers would be constructed by driving pneumatic caissons. While the caissons came down to bedrock uneven, the cutting edge came down per specification, a relatively rare accomplishment for the time. By January of 1900, the piers had been completed, and work on the new bridge would be suspended until the old spans could be dismantled. Falsework would be constructed under the truss spans, with large Howe trusses used in the falsework under the center spans. After the old bridge was disassembled, work was around the clock, 7 days per week to construct the new bridge. Temporary electric light plants were used at night to facilitate the construction of the bridge, and only two Sundays were not worked during the construction season of 1900. The new bridge would open to traffic by early 1901. It is believed that portions of the old bridge were either reused or sold to other railroads.

As constructed in 1900, the bridge consisted of four main truss spans, approached by a variety of spans on either end. The eastern main span (span #10) would be a 311-foot, 11-panel, pin-connected Parker through truss. The next span east (span #11) would be a 339-foot, 12-panel span of the same design. The western two main spans (spans #12 and #13) each utilized 311-foot spans, identical to span #10. The eastern approach of bridge would be constructed of two 138-foot, 8-panel, riveted double intersection Warren deck truss spans, approached by seven 30-foot deck plate girder spans, set onto steel bents. These 30-foot spans reused material from the 1878 bridge, with each span being constructed of four girder lines to form a double strength span. The western approach featured a 240-foot, 10-panel, pin-connected Pratt deck truss (span #14), a 138-foot, 8-panel, riveted double intersection Warren deck truss, three 57-foot deck plate girders and two 29-foot deck plate girders. The deck plate girder spans would be supported on steel towers, with the 29-foot spans forming the tower spans. Piers #1, #2 and the steel bent and tower footings would be reconstructed with concrete by company forces, while piers #3 and #4 utilized the stone and steel tower piers from the previous bridge. Piers #5, #6 and #7 were constructed of new stonework, and pier #8 reused as much of the old stone as possible. The east abutment reused the abutment from the previous bridge, while the west abutment was constructed by company forces.

Parker through truss spans became popular in the late 19th Century as an alternative to longer Pratt and Whipple spans. By the early 20th Century, the design was used mostly for medium length spans, with longer designs having been replaced by the Pennsylvania through truss design. The four main spans of this bridge utilize exceptionally long examples of Parker spans. It is likely that this design was sufficient for the required loading, and more economical than using a Pennsylvania truss at this location. The main spans all use laced vertical members, solid endposts and lattice portals, with the outside portals of the four spans having cutouts indicating the date and railroad. The easternmost main span utilizes a polygonal lower chord, designed to accommodate the reuse of pier #3. Span #14 utilizes a Pratt deck truss design, which was the most popular truss design in the late 19th Century. This span utilizes laced members, solid endposts and a deep floor. The shorter 138-foot spans utilized a double intersection Warren deck truss design, which had become popular with some railroads during the late 19th Century. These spans utilize riveted connections and solid members, typical for spans of this design. Span #9 utilizes an inclined endpost on the west end, designed to accommodate the reuse of pier #3. The use of different deck truss spans can be attributed to the preferred designs on the C&A. In 1900, the C&A preferred using riveted "lattice girder" spans for truss spans under 150 feet, and pin connected spans for truss spans over 150 feet. On large bridges like this, it is somewhat unusual for pieces of the old bridge to be reused in the replacement structure. Doubling girders to form "twinned" or "double strength" spans was a common technique railroads used to save on bridge costs. Often, girders could be combined to form a span that was suitable for required loading.

From 1900 until the fall of 1993, few changes were made to the bridge. During flooding in 1993, the western 138-foot deck truss and a 57-foot deck plate girder were destroyed. Repairs were made to the bridge, including the installation of four steel stringer spans, set onto new steel pile and concrete bents. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. In particular, piers #5, #6 and #7 appear to be in excellent condition. The author has ranked this bridge as being highly significant, due to a number of reasons. The Parker spans on this bridge are among the largest constructed for railroad use, and retain a high degree of historic integrity. The different deck truss designs represent different ideologies regarding truss design, and all remaining deck trusses retain a high degree of historic integrity. The east approach viaduct is notable for reusing portions of the first all steel railroad bridge constructed. Despite the alterations in 1900, these plate girders appear to demonstrate historical significance, and there appear to have been few modifications to the girders themselves. Finally, the bridge was a landmark project of August Ziesing, an individual who would go on to turn the American Bridge Company into an industrial powerhouse during the 20th Century. Despite the replacement of two spans on the west end of the bridge, the entire bridge continues to hold a high degree of historic integrity, and should continue to serve traffic for years to come.