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

by Henry Petroski

  Needless to say, the problem of interoceanic communication and de Lesseps’s scheme attracted the attention of American interests generally and James Eads in particular. In an 1880 address before the House Select Committee on Inter-Oceanic Canals, Eads offered his opinion:

  The question of the practicability of opening a tide-level waterway through the American isthmus is simply a question of money and of time. If sufficient money were supplied, and time enough were given, I have no doubt that, instead of the narrow and tortuous stream which Count de Lesseps proposes to locate at the bottom of an artificial canon [sic] to be cut through the Cordilleras at Panama, engineers could give to commerce a magnificent strait through whose broad and deep channel the tides of the Pacific would be felt on the shore of the Caribbean Sea, and through which the commerce of the next century might pass unvexed, from ocean to ocean.

  The science of engineering teaches those who practice it how the forces of nature may be utilized for the benefit of mankind, and it is the duty of the engineer when charged with the responsibility of solving an important engineering problem, by which his fellow men are to be benefited, to consider carefully how the desired results can be most cheaply and most quickly secured. Therefore, it is his duty to consider every method for the accomplishment of the end in view which science and nature have placed within his power, and to select from the fullness of their stores such methods as the precise teachings of mathematics and a knowledge of the laws which control the forces of nature assure him will certainly accomplish the desired result in the least time and for the least money.

  The method Eads had come up with was not a canal but a ship railway, in which fully laden vessels would be loaded onto great flatcars and pulled by teams of locomotives on multiple parallel tracks across the Isthmus of Tehuantepec. Such a trans-Mexican route would save ten thousand miles over the sea route via Cape Horn, and more than a thousand miles over the Panama Railroad route. Eads believed the ship railway could be completed long before de Lesseps’s canal, and at a lower cost, and the American engineer spent the remainder of his life promoting his novel scheme. Other American interests included a more conventional canal over a Nicaraguan route. The political and technical debate outlasted Eads: he died on March 8, 1887, in Nassau, in the Bahamas, where he was seeking support for his final, unrealized dream. No other engineer, no matter how young, could take it up with the vigor of Eads. Had he chosen to devote his more youthful energies to a trans-Mexican ship railway, we might not have the bridge that to this day memorializes him on his river. There would no doubt have been a bridge across the Mississippi at St. Louis before long, and certainly by the end of the century, but it would not have been Eads’s bridge. However, because his is the bridge that was built, it constituted a legacy from Eads and his assistant engineers, not only to the people who used and benefited from it, of course, but also, in its technical achievement, to the entire bridge-building fraternity, which everywhere in the last decades of the nineteenth century possessed the dreams, ambitions, and unbridled energies of youth.

  James B. Eads shortly before his death, in a photograph by Emil Boehl (photo credit 2.12)

  COOPER

  James Eads was an anomaly among bridge builders, in that his involvement with the genre began and ended with a single example, albeit one of historic proportions. His first and most ardent love was the Mississippi River itself, and he appears to have backed into bridge building more because of his civic involvement with the mercantile movers and shakers of St. Louis than because of any long-harbored dream to build a bridge greater than any other. Eads was, however, a consummate engineer, and once he got involved with the problem of bridging the Mississippi, it was as driving a challenge as was raising wrecks from the river’s bottom or channeling the river itself to the Gulf.

  Most engineers involved with bridge building in the late part of the nineteenth century and the early part of the twentieth could not have such a fleeting romance with iron and steel. With the railroads continuing to expand and to increase the power of their locomotives and the size of their rolling stock throughout this period, there was a constant need for stronger, larger, and more innovative bridges, and for engineers to do everything from creating their designs to putting up their superstructures. In America, these engineers were by and large of a different generation from Eads. Theodore Cooper was to be among those of the newer generation who rose to the top of the profession and became involved with building what would have been the greatest bridge in the world.

  Theodore Cooper, as a member of Rensselaer’s Class of 1858 (photo credit 3.1)

  Theodore Cooper was born in 1839 in Cooper’s Plain, in the western New York State county of Steuben, which would give its name to the finest products of the Corning Glass Works, now located nearby. Unlike Eads, who came from an itinerant family with a precarious financial future, Cooper was born into one of permanence and purpose. The son of John Cooper, Jr., a practicing physician, and Elizabeth M. Evans, young Theodore was one of nine children who grew up on land their parents settled on shortly after their marriage in Pennsylvania. The Coopers, among the earliest settlers of Steuben County, developed an estate there on land inherited from the elder Cooper’s maternal grandfather. When young Theodore decided that he wanted to study engineering, he did not have to rely upon a benefactor’s library for books. Rather, he traveled about 150 miles east-northeast to attend Rensselaer Institute and study toward the degree of civil engineer in that still-young institution. He graduated in 1858, in the class after Washington Roebling, who was two years older.

  Washington Roebling was, of course, the son of a famous engineer, who not only served as the young man’s mentor but also provided him with opportunities to gain invaluable work experience as an assistant on such projects as the Allegheny suspension bridge in Pittsburgh and, after service in the Civil War, on the bridge between Covington, Kentucky, and Cincinnati, over the Ohio River. Such privileged apprenticeships prepared Washington Roebling well to take over construction of the Brooklyn Bridge after his father died. Beyond his Rensselaer degree, Theodore Cooper had no such personal entrée into engineering. Rather, he started his career as an assistant engineer on the Troy & Greenfield Railroad and on the Hoosac Tunnel project in northwestern Massachusetts.

  A tunnel through Hoosac Mountain, which would be an important link on the route between Albany and Boston, had been proposed as early as 1819. In 1825, the younger Loammi Baldwin had identified a location near North Adams, Massachusetts, at which a five-mile tunnel could be driven almost due east through the mountain at a cost, he estimated, of no more than a million dollars. At the time, this was too dear for the Massachusetts Legislature, but the Boston & Albany Railroad Company began the task in 1848. It was expected to be a five-year project, but that was overly optimistic. In 1856, when little progress had been made, Herman Haupt, a seasoned engineer who had been trained at the U.S. Military Academy and gained much experience on railroad bridge and tunnel projects, was prevailed upon to help with the Hoosac Tunnel, by raising funds for it as well as overseeing its completion, and he resigned from the Pennsylvania Railroad to do so. It was in 1858, the year Haupt attacked the mountain with renewed vigor and with an improved pneumatic drill, that Theodore Cooper came on board to begin his engineering career. After three more years of work on the tunnel, however, it was only 20 percent complete, and, amid charges of corruption and mismanagement, the commonwealth of Massachusetts took over the project. With the outbreak of the Civil War, Cooper, who had risen to the position of assistant engineer, left the tunnel project to join the U.S. Navy. (The tunnel was not to be finally blasted through until 1874. After it opened to rail traffic the next year, its route could be advertised as the “shortest line between the east and west.”)

  As an assistant engineer in the navy, Cooper was ordered to the gunboat Chocura, then still under construction in Boston. He spent almost four years attached to the Chocura, which saw action at the siege of Yorktown and the battle of West Point,
served as a guardship on the Potomac, and took part in the blockade off Fort Fisher and along the Texas coast, among other campaigns. Cooper was ordered to the Naval Academy, then at Newport, Rhode Island, in June 1865, and then to Annapolis, Maryland, where the academy reopened that fall, as an instructor in the recently formed Department of Steam Engineering. He was in charge of all new construction at Annapolis for the three years he spent there, then undertook a two-year tour of duty in the South Pacific on the Nyack. Finally, after returning to Annapolis for two more years, he resigned his position as first assistant engineer to work for James B. Eads, with whom he may have become acquainted during the latter’s many trips to nearby Washington.

  Cooper was appointed by Eads in mid-1872, first as inspector of the steel being made at the Midvale Steel Works, and later as inspector of construction at the Keystone Bridge Company, where the parts were finished and tested before being shipped to St. Louis. These were important responsibilities; if the steel was not made to specified standards and did not have the same strength and flexibility as assumed in the design calculations, then all the engineering predictions of the finished bridge’s behavior were invalid. Such assignments in Pittsburgh were common beginnings for promising young engineers, but Cooper was already approaching his mid-thirties, and he must have been anxious for even more responsible work. By the end of the year, he was sent to the construction site in St. Louis to supervise the erection of the parts whose quality he had assured, and it was in this position that his reputation among bridge builders became more visible.

  When Cooper arrived in St. Louis, the superstructure of the bridge was well along, the trussed ribs arching almost one hundred feet over the river. Walking about on the incomplete superstructure must have been nerve-racking and was certainly dangerous, but Cooper gained a reputation for personally inspecting the erection of the superstructure daily. Indeed, he was absent only on one “wet, snowy day, when everything was covered with ice,” because he was “too stiff in the joints” from a fall he had taken a few days earlier. According to Cooper’s own account, he “tripped on an unbalanced plank” and fell ninety feet into the river, but “escaped uninjured, excepting a stiffness resulting from the shock.” He afterward elaborated on the incident to Calvin Woodward, the principal historian of the Eads Bridge, who related the story as follows:

  He was conscious (he said) of its taking him a long time to fall 90 feet. He thought of the probable force with which he would strike the water, and rolled himself in to the shape of a ball as much as possible. He struck the water he hardly knew how, and went very deep into the river,—nearly to the bottom, he thought. After what seemed another long interval, he reached the surface and struck out vigorously for shore. He then found that he still held in his hand the lead-pencil which he was using when he stepped on the treacherous plank. A boat from the East Abutment soon picked him up. In an incredibly short time he changed his clothes and walked into the office of the company as though nothing had happened.

  Several weeks after his fall, Cooper examined a tube that a workman had reported broken and found another tube broken also. With Henry Flad sick in bed at the time, Cooper ordered emergency measures taken to keep the unfinished bridge from collapsing, and he telegraphed Eads in New York of the alarming development. Eads first wondered if all their calculations had been in error, and if somehow extremes of temperature were straining the metal beyond its limits. After reflection, however, he recognized that relaxing somewhat the cables supporting the unfinished arches would relieve the tubes in the arch ribs of part of the strain that was causing them to break, and he telegraphed instructions back to Cooper. The cables were adjusted accordingly, and the danger passed. This incident was prophetic of a similar one thirty-five years later, when Cooper’s career was at its zenith. However, in that case, the absentee chief engineer would not be so fortunate in getting his telegram through to his assistant.

  After the Eads Bridge was completed, Cooper moved about for a while, in a manner not unfamiliar to engineers today. He served as superintendent of the shops for the Delaware Bridge Company, in Phillipsburg, New Jersey; worked as assistant general manager of the Keystone Bridge Company, in Pittsburgh; designed and built (i.e., oversaw the building of) the Laredo Shops of the Mexican National Railroad; remodeled and rebuilt the furnace plant of the Lackawanna Coal and Iron Company, in Scranton, Pennsylvania; and designed and built the Norton Cement Mills at Binnewater, New York. He was approved for hiring as an assistant to Wilhelm Hildenbrand, who had made the first drawings of the Brooklyn Bridge under the direction of John Roebling and who served as principal assistant engineer of the construction of the bridge under Washington Roebling, but it is not clear how extensively Cooper worked on that project. Nevertheless, with his broad and varied experience, he was able to establish himself as a consulting engineer in New York City in 1879.

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  The year 1879 is among the most infamous in the history of modern bridge building, for it was on the last Sunday of that year, December 28, that the Tay Bridge disaster occurred, an event that immediately affected the character of bridge design and construction endeavors throughout the world, was to affect Cooper in the twilight of his career, and to this day influences the way bridges are built and look. As with all bridges, the history of the Tay begins long before its name became familiar, even to engineers, and the nature of the bridge itself, or its influence on subsequent bridges, cannot be completely understood without understanding the circumstances surrounding its origins, design, and construction.

  In the 1850s, travel to the east coast of Scotland above Edinburgh was a grueling ordeal. Although the town of Dundee was only forty-six miles north of Edinburgh as the crow flies, even in the best of weather a railroad journey took over three hours, because there were two wide and unbridged estuaries to cross. Passengers who left Edinburgh on the 6:25 a.m. to Grafton had to change there to a paddlewheel steam ferry, which carried them across the Firth of Forth to Burntisland; here they boarded a train that took them through Fifeshire to Tayport, then disembarked and boarded another ferry to carry them across the Firth of Tay to Broughty Ferry, where they finally caught a train that took them to Dundee. This was largely the route of the North British Railway—a successful line in the south, but one that was fast losing business in Scotland to the Caledonian Railway. The Caledonian route to Dundee was a much more comfortable journey, albeit a longer one, taking passengers well westward out of their way, through towns like Stirling and Perth, where the two firths had narrowed to rivers and were more readily bridged.

  The word “firth” means “estuary” and is related to the old Norse word “fjord.” Unlike the Scandinavian arms to the sea, however, the Scottish firths are located not so much between steep cliffs as between gentle hills. This made ferry landings rather easily established, and would have made bridges and their approaches relatively uncomplicated, if the firths were not so wide near Edinburgh and Dundee. It may hardly have crossed the minds of railway directors and shareholders in the middle of the nineteenth century that bridges could be thrown across such great stretches of water, no matter how shallow these might be, and they accepted the limitations of “floating railways,” in which railroad cars fully loaded with coal or other commodities would be uncoupled at the water’s edge and rolled onto ferries, to be carried across the firth and then coupled to new locomotives for the continuation of the journey.

  Thomas Bouch, who devised the scheme of the railway ferries, was born to a sea captain and his wife in Cumberland in 1822. At the age of seventeen, young Bouch became associated with the famous Stockton & Darlington Railway, designed and constructed by the engineer George Stephenson, whose portrait now appears on the English five-pound note. Railroads had been used for some time to move loads of coal and other heavy materials between mines, forges, shipping points, and the like, often in small hand-pushed or horse-drawn cars. When steam locomotives came to be used, it was clear that railroads could also serve to transport goods and people
between towns. The Stockton & Darlington was among the first railways authorized by Parliament to be operated also for public transport, and September 27, 1825, when the first ticket was sold on the line, is often taken as the birthdate of the railways as we know them—true competitors of canals and carriage roads.

  East coast of Scotland, showing railway connections around the Firth of Forth and the Firth of Tay, circa 1890 (photo credit 3.2)

  In 1849, when he was twenty-seven, Bouch went to Scotland to become traffic manager and engineer of the Edinburgh & Northern Railway. He went on to design railway viaducts in the highlands, a tramway system for Edinburgh, and the railway ferries across the firths of Forth and Tay. When the Edinburgh & Northern was taken over by the North British Railway in 1854, Bouch proposed to the directors a bridge across the Firth of Tay, but some considered a two-mile-long structure “the most insane idea that could ever be propounded.” Opposition to the idea of a bridge at Dundee was not so much ridiculed as feared, however, in the town of Perth, about twenty miles up the Tay, where shipping interests worried about a bridge downstream blocking their access to the sea and their livelihood on the interior railroad. And one naysayer presciently articulated the fears of many along the wide, cold, and windy estuary: “The tremendous impetus of the icy blast must wrench off the girders as if they were a spider’s web, or hurl the whole erection before it.” In the final analysis, the long struggle between the Caledonian and North British railways for the Scottish traffic was the deciding factor.