Tallulah Falls Bridge, Spanning Tallulah Falls River on U.S. Highway 23/State Route 15, Tallulah Falls

Source document Quoted word for word from HAER GA-151. Not written, edited or summarised by this site.

Spanning Tallulah Gorge/Tallulah River on U.S. 15 in Tallulah Falls, Georgia, Rabun County UTM Readings: Tallulah Falls Quad - Zone 17 North End of Bridge Northing Easting South End of Bridge Northing Easting Date of Construction: - Engineers/Builder: Designed by the Georgia Highway Department - C. N. Crocker, Engineering Supervisor; A. d'Antignac, Division Engineer, R. M. Raffensberger, Resident Engineer: Virginia Bridge Company of Roanoke, Virgina furnished and erected all structural steel for the bridge.

Source document Quoted word for word from HAER GA-151. Not written, edited or summarised by this site.

The Tallulah Falls Bridge was constructed in to eliminate traffic congestion on the narrow roadway on top of the adjacent Tallulah Falls Dam 1 At the time it was constructed, the bridge contained one of the longest plate girder spans in the United States. The bridge is significant for the engineering aspects of its design. The siting of the bridge over Tallulah Gorge, which lends the bridge distinction, dictated the design of the bridge. Few, if any, of the other bridges in the state can compete with the dramatic setting of Tallulah Gorge whose rock walls rapidly drop to the river, leaving the bridge to cross approximately over the riverbed. Report Prepared By: Jayne H.

Maxwell, Transportation Planner III Georgia Department of Transportation Aviation Circle Atlanta, Georgia Date: June TALLULAH FALLS BRIDGE HAER No. GA-151 Page 2 The Tallulah Falls Bridge is located at Tallulah Falls, Georgia which takes its name from the series of waterfalls formed by the Tallulah River which in turn formed the Tallulah Gorge. The water flow for these falls was curtailed by construction of the Tallulah Falls Dam which formed a large reservoir and diverted the majority of the water via a tunnel to a hydroelectric plant further downstream in the gorge. The bridge was constructed in - to relieve traffic congestion on the narrow roadway on top of the nearby Tallulah Falls Dam. Research has not revealed where traditional crossings for the gorge were located.

Access to the gorge was originally from Clarkesville, a town twelve miles away, where horses and vehicles were provided for what was generally a camping trip. Later, overnight accommodations of various sizes and descriptions were established, especially after railroad access to the area was provided in A road of some sort provided vehicular access to the area, but was greatly improved in by the realignment of what is now U.S. 441 to partially follow the rim of the gorge. This and new highways into previously remote areas of the mountains allowed easy vehicular access to the area. Whether a bridge existed at the site of the present bridge and dam prior to is unknown.

The narrow roadway on top of the dam was a part of the original construction of the dam in but whether it serviced an existing road or a allowed a new route to be developed has not been established. A trestle provided railway travel over the gorge upstream from the dam until the rail line was closed and removed in The Tallulah Falls Bridge is a plate girder structure. The bridge measures 4" in overall length and in width. This width includes a 24' road surface and sidewalks on each side. The bridge was constructed using plate girders with parabolic flanges and is supported by hollow reinforced concrete piers.

Although plate girder construction was common by the time this bridge was constructed, the use of parabolic flanges enabled construction of a central span length of one of the longest plate girder spans in the United States at the time of its construction. The bridge was also notable at the time of its construction for its 90' cellular support piers, whose design permitted the reuse of forms. The inside forms were kept uniform while the architectural effects of the exterior were obtained by means of offsets in the outside faces. An article from in an engineering journal described developments in bridge engineering in the Western United States. The article discusses changes in design standards, technological advances, and a new emphasis on aesthetic aspects and appearance.

Economic constraints had resulted in structures which were functional, but unsightly. However, by a limited expenditure for improved architectural appearance was considered TALLULAH FALLS BRIDGE HAER No. GA-151 Page3 justifiable acc ording to the article. While this was first manifested in the addition of gingerbread, filigree, or other appended decoration, engineers eventually improved the appearance of concrete structures by utilizing simple lines and plain surfaces in proper proportions. This generally could be accomplished with a negligible increase in cost without inappropriately disguising the main lines of the bridge.

This emphasis on aesthetics may have evolved from the City Beautiful movement of the Regardless of the origins, the Tallulah Falls Bridge seems to be exemplary of this philosophy emphasizing aesthetic appeal. The use of the incised lines and grillwork as ventilators in the piers is consistent with the emphasis on line and form inherent in the bridge design. While plate girder spans represented the bridge of choice, having not yet been pre-empted by low-maintenance concrete stringers, the length of the central span was not typical of plate girder construction. The length of the central span was the one of the longest of a bridge of its type in the nation and the longest east of the Rocky Mountains.

The use of parabolic bottom flanges which enabled the utilization of the central span further removes this particular bridge from typical plate girder construction of the era. Research indicates that the significance of the bridge is derived from engineering aspects of its design rather than technical aspects of its construction. Plate girder construction had become common by this time in bridge construction however, the use of this type of construction in long spans was considered advanced technology. Engineering journals state that a span built in Topeka, Kansas in was the longest plate girder span in the country at the time of its construction.

This was apparently pre-empted by the Tallulah Falls bridge which was in turn supplanted by a span included in a viaduct in Cleveland, Ohio later in Other bridges with long spans are mentioned in subsequent articles in engineering journals. Apparently the Tallulah Falls Bridge is one of the earlier bridges exhibiting plate girder technology in longer spans. These span lengths have become less unusual as stronger steel has been developed. The Virginia Bridge Company of Roanoke, Virginia was contracted to furnish and erect all structural steel for the bridge. The bridge was constructed as a federal-aid project with all design work performed by personnel of the bridge department of the Georgia Highway Department.

Engineering supervision during construction was also handled by highway department engineers. Crocker was the engineering supervisor, A. d'Antignac was the division engineer and Raffensberger was the resident engineer. The setting itself which dictated the design of the bridge also rendered it distinctive in a context of Georgia bridges. Few if any other bridges in TALLULAH FALLS BRIDGE HAER No. GA-151 Page4 the state, whether constructed in the era of Georgia's historic bridge construction or later, can compete with the dramatic setting of Tallulah Gorge whose rock walls rapidly drop to the river, leaving the bridge to cross approximately over the riverbed. The setting also lends the bridge distinction.

Old bridge files at GDOT reveal that a suspension bridge was given consideration and an open spandrel concrete arch was actively pursued until the plate girder design was adopted. Either of the bridges would be considered significant in a context of Georgia bridge construction. No data has been located which gives the reasons or events leading to the selection of the plate girder design over those previously considered. Therefore, the role the aesthetics of the setting played in determining the existing bridge design as opposed to design parameters dictated by the site topography cannot be ascertained.

The use of the observation decks at the tops of the piers is evidence of public appreciation and interest in the natural beauty of the gorge and modern technology as embodied in the Tallulah Falls Dam. This design detail would probably not have been included if this bridge had been located in a more mundane setting. TALLULAH FALLS BRIDGE HAER No. GA-151 Page5 Sources Bowman, Valdo, "Bridges and Buildings." Engineering News-Record, Vol. 124 (lebruary 15, Bowman, Waldo, "Bridge Design and Construction." Engineering News-Record, Vol. 126 (February 13, Brittain, Dr. James E., A Brief History of Engineering in Georgia and Guide to 76 Historic Engineering Sites. Bicentennial project prepared for th-e~- Atlanta Chapter of the Georgia Society of Professional Engineers.

(Collections of Georgia Institute of Technology Library.) Brittain, Dr. James E., Professor of History of Technology, Georgia Institute of Technology, Atlanta, Georgia. Interview, March by Hal Cole. Crocker, "Georgia Builds 220 - Ft. Span Girder." Engineering News - Record, Vol. 122 (March 16, GDOT Maintenance Records Hancock, Carol Stevens, The Li ht in the Mountains - A Histor of Tallulah Falls School. Toccoa, Georgia: Commercial Printing Company, 197 Historic American Engineerihg Record (HAER) Inventory Sheet. Dr. Jim Brittain, Housecroft, Maurice, "Developments in Yestern Bridge Engineering." Civil Engineering; Vol. 10 (December, "Long Girders Used for Georgia Bridge." Engineering News-Record, Vol. 125 (December 5, Singleton, Jack, "Longest U.S.

Girder at Topeka." Engineering News-Record, Vol. 120 (May 19,