Engineers of Dreams: Great Bridge Builders and the Spanning of America

by Henry Petroski

  Engineers making final inspection of San Francisco-Oakland Bay Bridge (left to right): Charles Derleth, Jr., Glenn B. Woodruff, Leon S. Moisseiff, Henry J. Brunnier, Charles H. Purcell, Carlton S. Proctor, Ralph Modjeski, and Charles E. Andrew (photo credit 6.7)

  In an article in Engineering News-Record, subtitled “A Review of Preliminaries,” Purcell, Andrew, and Woodruff described some of the site and design alternatives they had considered. Though they confessed that it would be impossible for them, in this paper, to “consider the large number of tentative designs that were made,” they did discuss several, which included cantilevers longer than the Quebec Bridge and suspension bridges almost the equal of the Golden Gate. They admitted that the forty-one-hundred-foot suspension design “presented strong temptations” for its acceptance: “It required fewer departures from past practice than any alternate layout, reduced the number of piers to be constructed and was a more monumental structure.” However, it did present some drawbacks: it would have required a large amount of material to construct the San Francisco anchorage and to stiffen the truss against the wind. Furthermore, the longer span would have provided inferior clearance for shipping, required the destruction of some piers, and cost about $3 million more than the adopted design.

  Detailed considerations of the many alternative design possibilities led the group of engineers to recommend that the “bridge,” which was really two distinct bridges separated by a tunnel through an island, would consist of: (1) a unique pair of double-deck suspension bridges, each with a main span of 2,310 feet, arranged in tandem and sharing a common central anchorage in the middle of the water; (2) a 540-foot tunnel through Yerba Buena Island, with a bore larger than any other tunnel in the world; and (3) a great truss bridge laid out in a sweeping curve, with a cantilever section fourteen hundred feet long, which made it the longest and heaviest cantilever span in the U.S. and the third-longest in the world, flanked by a number of other spans exceeding five hundred feet. (It was on this latter portion of the bridge that a section of the upper deck fell during the 1989 Loma Prieta Earthquake, and the traffic disruption during the month when the bridge was closed for repairs provided many opportunities to reflect on the importance of the communications link that the bridge provided between San Francisco and communities, like Oakland, on the east side of the Bay.) In June 1933, the start of construction was marked on the island by a ceremony that included the explosion set off from Washington by President Roosevelt, and the symbolic beginning of excavation with the use of the golden spade. Chief engineer Purcell expressed the hope that traffic would be using the bridge by January 1937.

  The opening of the San Francisco-Oakland Bay Bridge actually took place late in 1936, ahead of Purcell’s public hopes as well as of the completion of the Golden Gate. Like all such events, the opening provided an opportunity to look both backward and forward. Among the episodes in San Francisco Bay history that was recalled on the occasion was the story of “a shrewd and likable fellow” named Joshua A. Norton, who had come to California during the 1849 Gold Rush, “attained considerable importance and amassed a fortune,” only to lose it and his mind. Returning to the area after years of absence, he declared himself “Emperor of the United States, Protector of Mexico and Sole Owner of the Guano Islands,” and issued paper money, which was honored by the locals, who humored him. Among the many imperial proclamations issued by Emperor Norton was one ordering the Coast Guard to blockade Carquinez Strait, long before Steinman’s cantilever crossed it, and one inviting Abraham Lincoln and Jefferson Davis to meet and arbitrate an end to the Civil War, an invitation they did not accept. But the document most on the minds of those celebrating the completion of the Bay Bridge was the following:

  PROCLAMATION

  We, Norton I, Emperor of the United States and Protector of Mexico, do order and direct … that a suspension bridge be constructed from the improvements lately ordered by our royal decree at Oakland Point to Yerba Buena, from thence to the mountain range of Saucilleto.… Whereof fail not under pain of death.

  Given under our hand this 18th day of August, A.D. 1869, and in the 17th year of our reign, in our present Capitol [sic], the city of Oakland.

  (signed)

  Norton I.—Emperor

  Though Norton’s bridge might have been an even grander span than the one built, at the same time snubbing San Francisco and making the Golden Gate Bridge unnecessary for getting to Marin County, at least from Oakland, the order certainly leaves no doubt that dreams of bridges were grand during the emperor’s reign. In 1936, the builders of the Bay Bridge saw the historical anomaly not as just an amusing footnote to the story of their own bridge, but as a testament to dreams of all kinds: “Who is bold enough to say that they will not some day be fulfilled?” Many decades after Norton flourished, the actual bridge inspired the Spanish-language poet Jorge Carrera Andrade to write Canto al Puente de Oakland, one verse of which reads, in translation:

  Your length like a river or like buoyant hope

  —miles of iron and of sky interwoven—

  can only be measured with the music

  or the metres of dream.

  Just as so many New York City bridges owe their existence and appearance to a group of engineers who worked for government bodies of one form or another, so did the San Francisco-Oakland Bay Bridge owe its final form to the talents and abilities of California state engineers like Purcell and Andrew. Consulting engineers play a crucial role whenever it comes to particular questions of detail, experience, and precedent, but the creative and political sympathy and savvy of career government employees around the nation have also played significant roles in shaping the built environment. Among such engineers was Conde McCullough.

  Conde Balcom McCullough was born to a physician and his wife in 1887 in Redfield, South Dakota. As a young man, he attended Iowa State College, from which he received his bachelor’s degree in civil engineering in 1910. After a first engineering job in Des Moines, he joined the Iowa State Highway Department, beginning as a designing engineer in 1911 and rising to assistant state highway engineer by the time he left, in 1916, to join the Civil Engineering Department at Oregon State College. Within two years, he had risen to the rank of professor and was head of the department, but he left the college the following year to become state bridge engineer for the State Highway Department. In order better to understand and deal with the legal constraints on his job, McCullough also went to law school, at Willamette University, receiving the bachelor of laws degree and being admitted to the Oregon State Bar in 1928. He wrote a considerable number of articles and books on bridges, economics, and law, including—with his attorney son, John McCullough—a two-volume work, The Engineer at Law.

  Artist’s conception of how the San Francisco—Oakland Bay Bridge would look when completed (photo credit 6.8)

  The completed San Francisco—Oakland Bay Bridge, showing its tandem suspension bridges, tunnel, and cantilever sections (photo credit 6.9)

  Conde McCullough’s creations in steel and reinforced concrete are even more responsible for Oregon’s overall reputation for beautiful bridges than are Lindenthal’s and Steinman’s efforts in the state. McCullough’s Bridge of the Gods and his Caveman and Rogue River bridges, this last incorporating the innovative prestressing techniques developed by the French engineer Eugène Freyssinet, are as graceful and whimsical as their names. The Coos Bay cantilever, which in 1936 completed one of the last major links in the Oregon Coast Highway, was designed by McCullough and was dedicated to him after his death in 1946. The Conde B. McCullough Memorial Bridge thus joined the exclusive group that includes the Eads Bridge at St. Louis and the Roebling Bridge at Cincinnati in being named for its engineer.

  Not every engineer who works for the government or a government-related agency gets an opportunity to be as broadly based in his work as McCullough did in the course of a career, but some certainly have and do. The shy Ammann, for example, who may have appeared on the surface to be apolitical and uninte
rested in law or public affairs, did engage in politics of a private nature. After all, it was he who wooed the future governor of New Jersey with plans for a Hudson River Bridge, which he in turn could advocate in his inaugural address, and for which he also could recommend Ammann himself as the project engineer. The independent Steinman, on the other hand, engaged more in a politics of a quite open and different kind—namely, the politics of his profession, for which he had begun to emerge, in the 1920s, as the most energetic and articulate spokesman.

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  In 1925, David Steinman, then president of the American Association of Engineers, wrote an article on “Outstanding Practice Problems of the Profession,” which appeared in Engineering News-Record. The article reported on the results of a survey that asked “representative engineers of national reputation for their views on ethical conduct in negotiations for professional services.” Steinman had not, of course, discovered this issue, which involved “how far the engineer may solicit an engagement without invitation; whether he should decline to do so competitively; whether a warning against competition should be included in the code of engineering ethics; and what can be done by the profession to combat the evil of inadequate fees.” However, though Steinman had no doubt heard a lot relating to such topics in Lindenthal’s office a decade earlier, the issues had become much more openly articulated in the meantime, going well beyond the pages of trade journals.

  The Conde B. McCullough Memorial Bridge over Coos Bay on the Oregon coast, one of the few bridges in America named for their engineers (photo credit 6.10)

  The American Society of Civil Engineers, begun in 1852 as the American Society of Civil Engineers and Architects, joined in 1916 the so-called founder societies, which then included the American Institute of Mining Engineers, dating from 1871; the American Society of Mechanical Engineers, from 1880; and the American Institute of Electrical Engineers, from 1884 and now known as the Institute of Electrical and Electronics Engineers. The proliferation of engineering societies in America followed only shortly after the same phenomenon in Britain, where the Institution of Civil Engineers, originally intended to encompass all of engineering that was not military, became only one among a plethora of specialized institutions, such as the Institution of Mechanical Engineers and the Institution of Electrical Engineers. These were formed in large part because proponents of new areas of developing technology were not so easily integrated into the existing societies by their more traditional counterparts. By the early years of the twentieth century, there was such a diversity of engineering societies, differentiated largely by the technical specialty of their members, that engineers felt that there was no single voice for the profession itself.

  Among the organizations formed “to address the social and economic interests of the engineer regardless of technical discipline,” was the American Association of Engineers, founded in 1914. There were two schools of thought among its founders, one of which “favored establishing a labor union affiliated with the American Federation of Labor,” and the other of which “visualized a professional society, avoiding the coercion normally inherent in labor organizations.” The latter philosophy prevailed, and the American Association of Engineers was about twenty-five thousand strong when Steinman assumed its presidency. At the time, the question of professional ethics was a lively topic of debate, even though the technical societies had been talking about such matters for fifty years. In 1912, the American Institute of Electrical Engineers and the American Society of Mechanical Engineers had finally adopted codes of ethics, and so, in 1914, did the American Society of Civil Engineers. The codes of these founder societies, as well as those of the American Association of Engineers, were thought to be too general and too subject to interpretation by some of its members, however, and in 1923 a number of “practice cases,” or case studies, had been issued to remove some of the ambiguities.

  This did not solve everything, of course, and when Steinman’s article on outstanding practice problems appeared in Engineering News-Record, it occasioned an editorial on the subject. According to the editors, it had to be admitted that the profession’s ethics were “neither satisfactorily formulated nor universally followed,” and existing codes were “made up of fine words which no one can controvert but of such embracing vagueness that interpretation is a matter of individual desire.” The editorial continued: “Certain things are permissible, certain other things lie beyond the pale. In between is territory where the engineer may roam at will. There is no Supreme Court which interprets the law and publicly enforces it.” Steinman’s undertaking for the American Association of Engineers was held out as a step toward “disciplinary control.” The “question of competition for business” was seen to be central to the problem, and engineers were thought to need “something comparable in solemnity to the doctor’s Hippocratic oath.” Unfortunately, it was a difficult time to be discussing such ideals, since business for engineers was no better than it was for the rest of the economy:

  In plain words there are more practising engineers, acting as principals, than there are jobs. There is the constant struggle for the majority of those principals to get enough of the existing work to maintain themselves as principals and to keep from falling back into the ranks of the employed, ranks that are apparently not so crowded as are the upper strata of the employing class. Work, too, must be sought to a large extent not from old clients, as is the case with the doctor and the lawyer, but from new interests who too frequently know nothing about engineers or engineering. Competition becomes a dominant factor in independent engineering, and the selfish motive strong in those who are trying to practice it.

  The problem of the code, therefore, is to set up an altruistic motive that will reinforce and justify the selfish one. It is not enough merely to assume that everybody agrees that certain things are not to be done; reasons must be given why they are not to be done. Because such reasons generally go back to the underlying necessities for truth and justice and honor, they lack force, for generalities on ethical conduct are always subject to individual interpretation. They must, therefore, be put on the more practical ground that self advancement lies also in the advancement of the profession one practices.

  These were tough times in which to aspire to such ideals, but discussions of the kind initiated by Steinman were seen as the way to proceed to raise simultaneously the general status of the profession and the level of its practice. In the meantime, another engineering organization, the Federated American Engineering Societies, was formed, with Herbert Hoover as its first president. This organization of societies, not of individuals, was created “to further the public welfare whenever technical knowledge and engineering experience are involved.” A third organization, the Engineers’ Council for Professional Development, was formed in 1932 “primarily to increase the input of the practicing profession into the educational process.” The issues remain to this day, having outlasted the organizations, which have been transformed several times since.

  Another development in the 1920s and into the 1930s was the increasing number of states that had instituted registration laws, thus placing “engineering on a par with law and medicine as legally restricted and recognized learned professions,” according to Steinman, who was among the most outspoken proponents of such registration laws. Between 1907, when Wyoming enacted the first such statute, and 1935, engineering registration was established in thirty-two states containing over 85 percent of the engineers in the country. Among the arguments he put forth in his many talks and articles on the subject were the following:

  The public needs to be protected against the quack, the incompetent, the unscrupulous, and the impostor, who do not belong in our profession but nevertheless practice in its name.…

  The public judges a profession by the examples it meets. When the public sees men who are unlettered and untrained holding themselves out as “engineers,” respect for the engineering profession is weakened or destroyed. When the public sees the word “engineer” on the s
hop window of a plumber, an electrician, a radio dealer, or an automobile mechanic, a wrong picture of the engineering profession is implanted.

  For years, the engineering profession talked about this problem—the abuse and misuse of the term “engineer”—but nothing was done about it. Finally with the aid of registration laws, means for successfully protecting our designation became available.

  At first, public officials were slow to co-operate. They declared that we could not “copyright the dictionary.” We pointed to the precedents of the other legally established professions which had successfully “copyrighted large chunks of the dictionary.” Any unlicensed man hanging out his shingle as a “lawyer,” a “physician,” a “dentist,” or an “architect” will be promptly arrested and subjected to the penalties of the law.

  Steinman believed so strongly in registration that he thought it should be a requirement for membership in engineering societies, but established groups like the American Society of Civil Engineers were not receptive to such an idea. Indeed, as with college degrees and other non-society designations they would not include the letters “P.E.,” indicating registration as a professional engineer, after the names of engineers appearing in society publications. Thus, in 1934, Steinman invited representatives of four relatively young state societies of professional engineers to join him at the Columbia University Club in New York for an organizational meeting of a new group, the National Society of Professional Engineers, whose membership would be restricted to registered professional engineers and whose activities would be limited to the “nontechnical concerns of all engineers.” Not surprisingly, Steinman became the society’s first president.