John Augustus Roebling

Civil Engineer

  • Born: June 12, 1806
  • Birthplace: Mühlhausen, Prussia (now in Germany)
  • Died: July 22, 1869
  • Place of death: Brooklyn Heights, New York

German-born American engineer

An academically trained civil engineer who worked in the middle decades of the nineteenth century when such talents were rare in the United States, Roebling fully exploited the potentialities of the suspension bridge, placing the United States in the forefront in construction of long-span, stable, heavy-load-bearing bridges for generations.

Area of achievement Engineering

Early Life

John Augustus Roebling (ROHB-lihng) was born in one of the German states of the Confederation of the Rhine that was incorporated into Prussia in 1815. The second largest of the German states, Prussia was in most respects the most advanced. Roebling’s parents were respected citizens of their ancient walled town, which was rich in Gothic architecture that later became one of the motifs in Roebling’s own work. Mühlhausen similarly enjoyed a rich cultural heritage, Johann Sebastian Bach, among other noted figures, having worked there. Because rapidly growing Berlin was Prussia’s political and cultural center, Roebling was sent to Berlin’s Royal Polytechnic School in 1822. When he was graduated in 1826, he had studied civil engineering, architecture, mathematics, and philosophy (under Georg Wilhelm Friedrich Hegel) and completed a senior thesis on suspension bridges.

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Life’s Work

After graduation, Roebling was employed for the next three years as a civil engineer on both public and military works for the Prussian government. Prussia, however, was an autocratic state in which the liberal, republican views that were to take root in the German state until 1848, views Roebling shared, withered. Because of such opinions, Roebling was officially listed as a subversive, and his career accordingly ended. Seeking a freer reign for his career and for his political convictions, he emigrated to Saxonburg in eastern Pennsylvania.

Over the next six years, Roebling unsuccessfully attempted farming. With the craze for internal improvements, particularly for canals and railroads, in full swing and trained engineers rare, Roebling returned to engineering in 1837, initially as a surveyor for the Beaver River Canal, then shortly afterward for the Pennsylvania Railroad. The enormous anthracite deposits of northeastern Pennsylvania, the frenzy to find economical means of getting the coal to market as it increasingly became the nation’s principal domestic and industrial fuel, ensured a demand for bridges.

In 1844, at the age of thirty-eight, Roebling earned his first commission, partly on the strength of his invention, in 1840, of a method of manufacturing wire-rope cable, essential for stable, heavy-duty suspension work. His first project, built to carry the Pennsylvania State Canal across the Allegheny River at Pittsburgh, was a suspension aqueduct for canal boats. Its masonry towers foreshadowed an Egyptian motif later to reappear in the Brooklyn Bridge. Roebling’s next four commissions, also aqueducts, were for the Delaware and Hudson Canal, a company then redesigning its anthracite-carrying canals from the coalfields of northeastern Pennsylvania to tidewater ports better able to compete with railroads. All were multispan suspension structures. Convenient for navigation, they were built without falsework—one of the advantages of suspension construction. Each consisted of troughlike flumes capable of carrying boats of sixty or more tons. The flumes were solidly embanked with fitted timbers and into transverse floor beams, all buttressed with sidewall trusses.

As on the famed Delaware Aqueduct, which remained in use until the 1970’s, the shore piers and masonry spans were company built. All the suspension work and its loads were designed and built by Roebling. Indeed, the Delaware Aqueduct was a handsome, thousand-foot span hung on eight-and-one-half-inch wrought-iron cables. Aware of the cable’s coming importance, Roebling, in fact, founded his own wire-cable factory in Trenton, New Jersey, in 1849, just prior to completion of his Delaware and Hudson commissions.

In the meantime, a fire in Pittsburgh and the destruction of the Monongahela River’s Smithfield Bridge in 1846 brought him a commission for his first vehicular suspension bridge. With two shore abutments and six river spans, it stretched fifteen hundred feet. The deck was carried by wrought-iron rods hung from wire cables, which Roebling spun onshore. Until traffic weights became too great, the bridge was in all regards a success, resulting, late during the 1850’s, in construction of an identical bridge over the Allegheny River at Pittsburgh’s Sixth Street. In this case, however, there were two differences: First, Roebling spun his wire cable on the bridge; second, his son, Washington, joined him, thus inaugurating his own career.

In 1851, John Roebling undertook his greatest challenge yet: construction of a railway suspension bridge across the Niagara River at Niagara Falls, New York. After a brilliant career, Charles Ellet, Roebling’s predecessor, resigned his commission for the job, effectively ending his career. Moreover, leading engineers in both the United States and Europe considered the task impossible. Roebling designed a double-decked structure: the upper one carrying the mainline of the Grand Trunk Railway and the Great Western Railway of Canada, and the lower one serving normal vehicular traffic. The Niagara gorge was deep; the river was deep and swift; the span to be covered on an absolute level was 821 feet from shore to shore. Roebling’s design consisted of four ten-inch cables, each of 3,640 wires, hung from masonry towers. Characteristically, the load was carried by the cables and reticulations of radiating stays. Roebling completed this, the first of the world’s railway suspension bridges, in 1855.

Meanwhile, Roebling rebuilt an Ellet bridge at Wheeling, West Virginia, and by 1856, he had embarked on ten years of frustrations—finances, ice, floods, and war—constructing a twelve-hundred-foot span across the Ohio River between Cincinnati and Covington, Kentucky. Since its opening in January, 1867, nevertheless, with its design unaltered, it continues in use, an even greater tribute to his engineering genius, tenacity, and industry than his remarkable Niagara Bridge.

Roebling’s last and monumental work was begun in 1867, with his appointment as chief engineer for the New York Bridge Company, whose objective was bridging the East River between lower Manhattan and Brooklyn, then two separate cities. The growth of each dictated a need for the most efficient connections. River traffic was enormous; rail and shipping connections were awkward and inefficient; and, though a tidal river, the East River severed both cities and halted traffic by freezing over or being covered with ice floes periodically. Proposals for a bridge began at least by 1811, and, in 1857, Roebling made his own bid. The Civil War and objections from the United States Army Engineers shelved work until 1869. Roebling designed an unprecedented structure with a main span of 1,595 feet.

Though built to Roebling’s specifications, the great bridge, which came to symbolize not only New York’s greatness but also the aesthetic and structural abilities of American engineering, was completed by Washington Roebling fourteen years after his father’s death. On his initial survey in July, 1869, John Roebling’s toes were crushed against pilings by a ferry, and he died of a tetanus infection July 22, 1869, in Brooklyn Heights, New York.

Significance

Although Roebling has been popularly identified with the design of the magnificent Brooklyn Bridge, an American symbol as well as an example of artistic engineering, one of his major contributions lies elsewhere: He, along with a handful of others, demonstrated the necessity for, and the superiority of, professionally trained engineers and the passing of those who, however ingeniously, even brilliantly, worked by “guess and by God.” This was especially true of bridge builders, who were increasingly confronted by the broad, swift rivers of America and by the vastly heavier burdens that had to be borne by their structures during rapid industrialization.

Roebling did not invent the suspension bridge: As a simple form it was thousands of years old. On a modest scale and in modest circumstances, suspensions were being improved even as his career began. The precision of his designs, his mastery of wire-cable manufacture and use, and his mathematical assessment of loads and stresses that lend special character to all of his constructions, whether his aqueducts, his Wheeling, Pittsburgh, Cincinnati, or Niagara structures, however, made him the acknowledged master of suspension forms. By his boldness in adapting his designs to the peculiar needs of the American environment, he revolutionized bridge construction throughout the world. This was a legacy passed on not only by his son’s completion of the Brooklyn Bridge but also by professional engineers everywhere.

Bibliography

Cadbury, Deborah. Dreams of Iron and Steel: Seven Wonders of the Nineteenth Century, from the Building of the London Sewers to the Panama Canal. New York: Fourth Estate, 2004. A popular history of major nineteenth century construction projects, including the Brooklyn Bridge. Provides information about Roebling’s involvement in the project as well as details of the bridge’s design and construction.

Condit, Carl W. American Building: Materials and Techniques from the Beginning of Colonial Settlements to the Present. Chicago: University of Chicago Press, 1982. A standard study; chapters 8 and 12 are on Roebling. Excellent technical discussion of bridge construction, including the suspension work of Roebling, among others. Also strong on historical contexts of these developments. Readable and widely available.

‗‗‗‗‗‗‗. American Building Art: The Nineteenth Century. New York: Oxford University Press, 1960. As excellent as all of Condit’s studies. Concentration not only on building techniques but also on the aesthetics of structural architecture. Chapter 5 is particularly relevant to Roebling and suspension bridges.

Kirby, Richard S., and Philip G. Laurson. The Early Years of Civil Engineering. New Haven, Conn.: Yale University Press, 1932. Standard and excellent. Includes portraits and brief biographical sketches of Roebling and many other major civil engineers of national and international note. Chapter 5 is especially relevant.

Latimer, Margaret, Brooks Hindle, and Melvin Kranzberg. Bridge to the Future: A Centennial Celebration of the Brooklyn Bridge. New York: New York Academy of Sciences, 1984. A literary as well as a technical survey. Sound and accurate.

McCullogh, David G. The Great Bridge: The Epic Story of the Brooklyn Bridge. New York: Simon & Schuster, 1972. Reprint 2001. A detailed, well-written, and meticulously researched popular history of the Brooklyn Bridge. The 2001 reprint includes a new introduction by the author.

Steinman, David B., and Sara Ruth Watson. Bridges and Their Builders. New York: G. P. Putnam’s Sons, 1941. Expertly done by engineering scholars. A fine survey.

Vogel, Robert M. Roebling’s Delaware and Hudson Canal Aqueducts. Washington, D.C.: Smithsonian Institution Press, 1971. Fine monograph on Roebling’s early work. Technically detailed with reproductions of Roebling’s designs. Useful for understanding Roebling’s later works.

May 24, 1883: Brooklyn Bridge Opens.