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

by Henry Petroski

  While the board studied Lindenthal’s plans, a debate raged in the pages of Engineering News over the relative merits of eyebar chains and wire cables for suspension bridges. Wilhelm Hildenbrand, who had drawn the earliest plans for the Brooklyn Bridge and who was now engineer of cable construction for the Roebling’s Sons Company, pointed out that eyebars were not a novelty, having long been used in Europe almost exclusively and even in America for “small suspension bridges.” Though the reasons given for the design change “might be accepted, unquestioned, by a private company from its chosen engineer, and in that case would probably remain unchallenged,” Hildenbrand asserted that the commissioner of bridges of the city of New York could not prevail so easily, for the switch from cables to eyebars would add “two to three millions of dollars” to the cost of the Manhattan Bridge. By Hildenbrand’s calculations, had the Williamsburg Bridge been built with eyebar chains rather than cables, its cost would have been increased by over $3 million. Although the editors of Engineering News might have been more supportive of Lindenthal in years past, they were not now, when he was being challenged by “one of the most experienced suspension bridge engineers in the country.” Hildenbrand had been associated with New York engineering projects since 1867, but Lindenthal had yet to have a single design of his own realized in the politically charged city. If he had hoped to use the power of his office to redesign a New York bridge to his own prejudices, he was not going to have an easy time of it, although at first it appeared that he might get his way.

  Detail of an eyebar suspension system (photo credit 4.17)

  When Lindenthal was about to submit his plans for the Manhattan Bridge to the city’s Art Commission, which offered opinions on the aesthetics of large structures, the board of engineers issued a preliminary report. According to the engineers, who believed that the chains had decided advantages with regard to erection and maintenance, “they are to be preferred to wire cables whenever the cost of the chains is not materially greater.” The final report, which had awaited the results of tests of material and information on the availability and cost of eyebars, was issued in June, with a unanimous recommendation for the adoption and execution of Lindenthal’s design, even though no firm cost comparisons were yet available.

  Diagrams showing how suspension bridges may be thought of as inverted arches (photo credit 4.18)

  Hildenbrand, however, found the final report “even more disappointing than the preliminary report.” It was “altogether so non-committal and spiritless that it is to be wondered whether the Mayor will consider it worth the money it has cost.” The report was indeed confusingly terse and vague, and Hildenbrand was correct in observing, “That the experts are all engineers of high professional standing does not alter the facts and figures, nor does it make the weak points in their report stronger! It merely emphasizes the weakness.” Engineering News and many other observers thought that a sensible way to resolve the issue would be to invite bids for both eyebar-chain and wire-cable designs and thus compare hard cost estimates, but the city appropriation mechanism did not allow such a commonsensical course, and so the debate continued.

  Though the Municipal Art Commission approved Lindenthal’s design, having reservations only about the decorations on the towers, there remained strong differences of opinion as to the comparative aesthetics of chains versus cables. George W. Colles, a Canadian engineer, wrote to the editor of Engineering News that “a chain-bridge is a very ugly thing—excusable only on grounds of engineering expediency.” He thought that New York was “ugly enough already,” and that it was “bad enough to have skeleton-bridge-towers,” like those on the Williamsburg, “without the added eyesore of a chain-bridge.” Colles decried the report of the experts as an example of a widespread “engineering impressionism,” by which the opinions of experts were defended solely on the basis of their being declared experts. He observed that this “merely shifts the burden of the real decision from the engineer to the capitalist.” Specifically addressing the claim of Lindenthal and the experts regarding the accessibility of chains for inspection, Colles correctly pointed to the “innumerable crevices and cracks which invite capillary absorption and subsequent corrosion,” a problem that was to be the root cause of the collapse of the bridge over the Ohio River at Point Pleasant, Ohio, in 1967. That structure was nicknamed Silver Bridge because it was among the first to be painted with aluminum paint, but it was found not to be very easy to maintain or inspect the tight details where the eyebars were connected to one another, and where cracks could grow to dangerous proportions and lead to the bridge’s sudden collapse.

  The debate over the Manhattan Bridge continued, with Lindenthal himself responding to letters attacking his Pittsburgh chain bridge as the “ugliest of the three” over the Allegheny and pointing out its early foundation problems. In an editorial, Engineering News announced that some of its readers had gotten the impression that the preponderance of letters in support of wire cables reflected the editorial stance of the journal, and it invited more letters from supporters of eyebars. Perhaps in response to such criticism, which may very well have been coming from Lindenthal himself, the journal began to supply him with proof copies of letters, so that he might respond in the same issue. The commissioner’s frustration began to show in his style, his longish letters seeming more and more frequently to end in sarcasm and condescension or worse. In response to a letter from Hildenbrand on the comparative strength of East River bridges, for example, the value of his opinions was estimated by Lindenthal to be “no greater than the value of the weather prophecies in a Farmer’s Almanac.” He dismissed another correspondent by saying that he had “yet much to learn in bridge engineering before essaying to discuss that intricate subject.” By the end of 1903, an election year, all parties involved seemed to be out of patience, and Engineering News editorialized that “the best way for the new administration to decide whether it shall build an eye-bar bridge or a wire cable bridge across the East River at the Manhattan Bridge site will be not to build any bridge at all.”

  If Engineering News abandoned Lindenthal, The New York Times did not. The newly elected mayor appointed a new bridge commissioner, George E. Best, and he decided to throw out Lindenthal’s design and return to the previous one. The Times in turn accused Best and his advisers of “personal spite against his predecessor, Commissioner Lindenthal, and a fixed purpose not to do anything that Mr. Lindenthal proposed.” As late as 1906, the newspaper was still advocating a chain over a wire bridge and calling for competitive bids to settle the question. In the end, however, Lindenthal’s tower designs, modified at their base to be more rigidly connected to the foundations, were all that survived of his ideas. The first strands of wire were run across the East River in 1908, after Mayor George McClellan announced that the bridge would be completed in December 1909 and that he would walk across it before his term of office expired. In late 1908, the mayor himself pulled a lever sending the last of the wire strands across the East River; the Manhattan Bridge was formally opened on December 31, 1909, the last day of McClellan’s administration.

  Views of the towers of the Manhattan Bridge, as redesigned in 1904 as a wire-cable structure (photo credit 4.19)

  When the Quebec Bridge collapsed during its construction in 1907, large bridges everywhere came under scrutiny. Rumors about the soundness of the Williamsburg Bridge began to surface, and concerns were also raised about the design of the Manhattan Bridge. The engineer appointed “to watch the construction of the new bridge” and check the plans was Ralph Modjeski, described in a contemporary report as “the leading engineering authority on bridges” in America, if not the world—in large part because of his membership on the board of engineers for the reconstruction of the Quebec Bridge. Although he had begun his bridge-building career twenty years earlier with the design of a major double-deck railway-and-highway structure across the Mississippi at Rock Island, Modjeski was still often identified in the popular press as the son of the well-known actress Ma
dame Modjeska, his name sometimes being misspelled with the feminine ending. In fact, the original spelling of their surname was much more complex than either had come to use in America.

  Rudolphe Modrzejewski was born in Cracow, Poland, on January 27, 1861, the son of Gustav and Helena Modrzejewski, who, as Helena Modjeska, was to become known as “the première tragedienne of her time.” According to his mother’s memoirs, Rudolphe came to America with her for the first time in 1876, when they visited New York, Philadelphia, and the Centennial Exposition. As they crossed the Isthmus of Panama on the first transcontinental railroad, on their way to California, the young man declared that “someday he would build the Panama Canal.” Although she remembers him as “even then determined to become a civil engineer,” a career as a pianist was evidently also a possibility, for he had been well trained musically and was said to be a leading exponent of Chopin. Indeed, young Ralph, as he preferred to be called in America, was at one time a fellow student with Ignace Paderewski.

  The engineer-to-be practiced piano a great deal while traveling with his mother; throughout his life, he was known to play the instrument almost every evening and for a couple of hours each Sunday. It may have been in his travels to America that Ralph Modjeski saw the needs and opportunities for artistry in a medium that used steel thicker than piano wire, but the young man decided to take up the study of civil engineering where it had first been taught, at the Ecole des Ponts et Chaussées, in Paris.

  Writing three decades later, Madame Modjeska did not mention any difficulty her son had in getting into the prestigious school. However, decades later still, he himself would recall the experience, on the occasion of his receiving the Washington Award. This award was established by the Western Society of Engineers “as an honor conferred upon a brother engineer by his fellow engineers on account of accomplishments which preeminently promote the happiness, comfort, and well-being of humanity.” The selection, made upon the recommendation of a commission representing the major national engineering societies and the Western Society of Engineers, was first bestowed in 1919 on Herbert Hoover, “for his pre-eminent services in behalf of the public welfare.” Among the other eight engineers honored before Modjeski were Arthur Newell Talbot, founding professor of theoretical and applied mechanics at the University of Illinois, and Michael I. Pupin, for his work on long-distance telephoning and radio broadcasting. Ralph Modjeski himself was recognized “for his contribution to transportation through superior skill and courage in bridge design and construction.” At the awards ceremony, he remembered how he had become an engineer and why, and he spoke of his perseverance toward his goal:

  When I was four years old I got hold of a screwdriver. This gave me an idea. I immediately investigated what this screwdriver was for and practiced on a door lock of the drawing room of the house we lived in and took it all apart. I could not put it together again. And my father said, “You will be an engineer.”

  I persisted in that until … I failed in the examination for entrance to the Ecole des Ponts et Chaussées where there were 25 places and 100 candidates. Then for about six months I practiced music six and eight hours a day. After six months I began to think, and at the end of nine months had thought out my problem and joined the preparatory school and three months later I passed the examination into the Ecole des Ponts et Chaussées.

  In 1885, Modjeski graduated first in his class, and he returned to America to build bridges, beginning his career under George S. Morison, who has been described as the “father of bridge building in America.” In 1893, the young engineer opened his own office in Chicago, as a senior member of Modjeski & Nickerson, one of the several engineering firms with which he would associate his name throughout his long career. He soon found himself engaged in enlarging the Rock Island Bridge over the Mississippi River. After that, Modjeski would work on or direct, often as chief engineer, the design and construction of a wide variety of bridges, in a variety of locations, including, in chronological order: Thebes, Illinois; Bismarck, North Dakota; Portland, Oregon; Peoria, Illinois; St. Louis, Missouri; Quebec, Canada; Toledo, Ohio; Memphis, Tennessee; Keokuk, Iowa; Metropolis, Illinois; New London, Connecticut; Poughkeepsie, New York; Cincinnati, Ohio; Omaha, Nebraska; Wenatchee, Washington; Clark’s Ferry, Pennsylvania; Harrisburg, Pennsylvania; Tacony, Pennsylvania; Detroit, Michigan; Melville, Louisiana; Louisville, Kentucky; Evansville, Indiana; Washington, D.C.; Cairo, Illinois; Davenport, Iowa; and New York, New York. On the occasion of his receiving the Washington Award, Modjeski was said to have “to his credit more large bridges than any other man.” But that alone was not why he would receive the Washington and other awards later in life. The reason, according to Ralph Budd, president of the Great Northern Railway, was simple:

  It is that Ralph Modjeski is inherently an artist. He has not chosen oil, or dry point, or marble, or even music, in which he doubtless would have ex-celled, to express himself, but steel, and stone, and concrete. Using these as his chosen media, “by a pleasing simplicity of form and reliance upon the quiet dignity of the long spans whose members gracefully express function free from superfluities,” he has made of bridge building a recognized art without in the least minimizing its importance as a science.

  Ralph Modjeski, perhaps in his late forties (photo credit 4.20)

  Many engineers who would receive such encomiums later in life often traveled a long and dispiriting road before reaching the podium among “prolonged applause,” but few matched Modjeski’s heightened sense of theater. Between 1905 and 1915, on the Oregon Trunk Railway, for example, Modjeski served as chief engineer for a series of bridges, including one over the Columbia River and a daring arch that spanned 340 feet at a height of 350 feet over a most dramatic construction site on the Crooked River. Overlapping with this responsibility was his much more visible presence as a member of the Government Board of Engineers for the second Quebec Bridge, from 1908 to its completion in 1917. His posing with other engineers astride one of the bridge’s thirty-inch-diameter steel pins and standing inside one of the redesigned seven-by-ten-foot lower chord members, demonstrated his sense of showmanship.

  Modjeski’s theatrical personality would come even more to the fore when he worked as chairman of the board of engineers and chief engineer for the Delaware River Bridge between Philadelphia and Camden, New Jersey, now known as the Ben Franklin Bridge, which with a main span of 1,750 feet would be the longest suspension bridge in the world when completed in 1926. Modjeski’s experience as an advance man for his mother and his gift for public relations would serve him well on that project, as it had in the earlier Quebec experience, for there survive photographs of him with various groups of engineers, directors, and city officials at seemingly each stage of construction. When the foot bridges for the Delaware River project were completed on August 8, 1924, chief engineer Modjeski would lead politicians from both states on the first official crossing from Philadelphia to Camden. It was to be a very warm day, and many in the party would shed their jackets during the steep climb to the top of the Philadelphia tower, but, as if to defy the sun itself, Modjeski would remove only his straw hat. After descending to the center of the main span, various members of the group, including Modjeski, would make speeches before a microphone that would be set up there by the Philadelphia radio station WLIT.

  A sense of showmanship displayed by engineers on one of the thirty-inch-diameter pins for the Quebec Bridge (left to right: G. F. Porter, engineer of construction, and G. H. Duggan, chief engineer, St. Lawrence Bridge Company; C. N. Monsarrat, chairman and chief engineer, and Ralph Modjeski, member, Government Board of Engineers) (photo credit 4.21)

  Public relations was not so effective for Modjeski or anyone else connected with the construction of the politically contested Manhattan Bridge, however. Aften ten months of study, Modjeski’s detailed technical report on the bridge was issued in September 1909. Though it suggested that the foundation of the Manhattan anchorage might have had an improved design, overall it gave the struct
ure “a clean bill of health.” At 1,480 feet between towers, the Manhattan was shorter than the suspension bridges that flanked it, the Brooklyn and the Williamsburg, but it was distinguished for both its political and its technological significance.

  The Manhattan Bridge was to have four trolley tracks and four elevated or subway tracks, but they were not yet installed, nor was all the pedestrian decking, when the bridge was dedicated on the final day of 1909, in part because a new city organization had taken rapid-transit arrangements out of the control of the bridge commissioner. When the Manhattan Bridge carried heavy rail traffic over the ensuing years, it would be found that, because of the arrangement of the rails, considerable twisting of the deck would take its toll on the structure. It would turn out that this was due in large part to the bridge’s having been designed by employing the analytical tools of the then new deflection theory devised by the Austrian Josef Melan to take into account the coupled action of the deck and suspension cables. Leon Moisseiff, an engineer with the Bridge Department, introduced the method of calculation into American bridge building through his work on the Manhattan Bridge. (Lindenthal actually raised some questions about the new calculation scheme, but his concerns were dismissed.) Moisseiff would go on to employ the method as engineer of design under Modjeski on the Delaware River Bridge, and virtually all other large American suspension bridges were to be designed in the same way—until the Tacoma Narrows Bridge failed the very year it was completed, in 1940. But this is getting ahead of the story.