October/november 1983 | Volume 34, Issue 6
It was built by Roebling, connects two cities, is a landmark of American engineering, and looks just like it but is…
IN THE SPRING of 1869 a party of engineers, politicians, and businessmen left Brooklyn and headed west in a special train. With them was John Augustus Roebling, the sixtytwo-year-old German-born engineer who had completed his plans for a massive bridge over New York’s East River.
Roebling’s wire-rope business had long since made him a fortune; he had started making metal cables merely to haul canal boats uphill but had gone on to pioneer their use in bridge building. By the 186Os he knew more than any man alive about suspension bridges. But this new project was so ambitious that he thought it would be best if his backers saw firsthand what he had accomplished. So the party steamed west to Pittsburgh, where Roebling had put up his first bridge a quarter of a century earlier, and to Niagara Falls, where he had spanned the cataract with a wistful, frail-looking web that astounded the visitors by effortlessly bearing the weight of moving trains. But the structure that most clearly prefigured Roebling’s new work was the suspension bridge that crossed the Ohio at Cincinnati.
He had finished it just three years before. The job had taken twenty years from the time he submitted his first proposal, and during those two decades he had been beset by every possible frustration and setback. Even in the light of what he hoped to undertake now, the Cincinnati bridge was an impressive achievement. His party certainly thought so: “It … broke upon us all at once,” wrote one of them, “the stateliest and most splendid evidence of genius, enterprise and skill it has ever been my lot to see.”
The idea for the bridge was almost as old as Cincinnati itself. As early as 1815 a promoter wrote that “some enthusiastic persons already speak of a bridge across the Ohio at Cincinnati” but conceded that “the period when this great nroiect can be executed is certainly remote.”
It seemed less remote in the 184Os. By then, an engineer named Charles Eilet had thrown the first important suspension bridge in the country across the Schuylkill. Eilet was the only man in America who approached Roebling in bridge-building ability. Nervous, intuitive, and largely self-educated, he was a folk engineer of sorts, and a gifted one. He had returned from a year of study at the Ecole Polytechnique in Paris committed to building suspension bridges and was busy proposing to put one across the Ohio at Louisville, Maysville, Marietta, or Wheeling. Thus goaded, the city fathers of Covington, Kentucky, across the river from Cincinnati, passed a resolution calling for a bridge of their own, and early in 1846 the Covington and Cincinnati Bridge Company came into being. Roebling and Eilet were invited to submit proposals. Only Roebling replied. He put forward a couple of possibilities, one of them a suspension bridge whose single twelve-hundred-foot span would arc over the Ohio a hundred feet above the water.
The bold scheme provoked a frenzy among ferryboat owners and steamboat men. They were against it, of course, but so too, it seemed for a while, was everyone else: the bridge piers, opponents claimed, would make the river flood; steamboats would not be able to pass; factories would rush across the river to cheaper sites, leaving Cincinnati a ghost town.
Roebling came west in May, did some surveying, and calmly answered his critics. The river wouldn’t flood, Cincinnati wouldn’t fall into decay. The center of the span would be higher than the tallest steamboat stacks, and even if it weren’t, he said, tall stacks were useless anyway. “If,” he concluded, allowing himself a rare flick of irony, “they could be forced from our rivers by some low bridge, it would be the greatest service which would be rendered to the navigation of our western waters.”
Despite Roebling’s trenchant refutation, the project had lost momentum. It was not until Eilet actually began work on an Ohio River bridge at Wheeling, Virginia, that the Cincinnati leaders stirred. Eilet’s new bridge would have a record-breaking span of over a thousand feet, and the Cincinnatians, impressed, asked him in 1849 for his views on a bridge for their city. A single-arch suspension bridge was the answer, he said: “Spanning the Ohio like a rainbow, it cannot fail to become an object of admiration to the country, a most striking monument to the enterprise of the day, and a worthy ornament to your beautiful and flourishing cities.”
The sponsors liked the sound of this, but the bridge company found it hard to raise money: railroads were sopping up most of the spare capital. Seeking a practical example by way of advertisement, the sponsors suggested that a small suspension bridge be built over the nearby Licking River. Local engineers finished the job in January of 1854. The bridge had been open to traffic for two weeks when it collapsed under a herd of cattle.
Five months after that, news came from Wheeling: “A giant lies prostrate in the Ohio, and against his huge and broken ribs and iron sinews, snapped asunder, the waves are dashing scornfully, sending up a sound the most doleful that ever fell upon the ears of our citizens.” Eilet’s bridge had failed.
Roebling knew just what had gone wrong. “Suspension bridges have generally been looked upon as loose fabrics hung up in the air,” he said, “as if for the purpose of swinging.” But it was not enough merely to sling a heavy roadway from huge cables. Although “weight is a most essential condition,” it “should be simply an attending element to a still more important condition, viz: stiffness .” For stiffening he used diagonal stays that slanted across the vertical suspenders that held the roadway to the cables; he was that very moment weaving them into the fabric of his Niagara Falls bridge.
The Cincinnati sponsors knew nothing of stiffening, however; they knew only that suspension bridges fell apart. Again the project came to a halt. Here matters might have rested forever, had it not been for a vigorous and sanguine local businessman named Amos Shinkle. He sold coal to steamboats and owned three of them himself, but he wasn’t scared that a bridge would drive him out of business. Nor was he frightened of suspension bridges; a booster of every kind of transportation, he set about getting himself elected a director of the played-out bridge company. With the same energy he’d shown ever since he’d been a f armboy leaving home with seventy-five cents in his pocket to make a life for himself on the river, Shinkle badgered the Kentucky and Ohio legislatures into passing amendments allowing an increase in capital stock. Before long the company sent for Roebling.
The engineer had set up shop in Cincinnati by August of 1856 and was fretting because he couldn’t start work. Shinkle had reinvigorated the bridge company too quickly; he had $314,000 to spend, but no materials had arrived, and no machinery was on hand. When work finally did begin, however, it went smoothly—on the Covington side, at least. There workers had no difficulty digging down to the blue limestone bedrock; they finished the excavation in three weeks. Big oak beams were laid along the bottom of the pit, and a second layer was put down crosswise on top of them. Another immense wooden grille went on top of this one, and then another until there were thirteen courses. With the interstices pumped full of concrete, they became the foundation for the tower.
Over on the Ohio shore, however, things went wrong from the start. As the excavation sank, it tapped the wells back of Cincinnati, and water flowed into the pit. Roebling drained it—“raising clean water is an easy process”—but then river water began to seep in. This was not clean water, Roebling said, but “large masses of soft mud and sand. ” His crew wasted weeks fussing with patent rotary pumps. Then there was no more time: autunm rains were lashing down, and the river was rising. Roebling had to improvise. He had no time for such niceties as casting or turning metal—he pretty much had to make do with the resources that would have been available to a medieval cathedral builder. Seizing on a supply of three-inch-thick pine planks, he sketched out a design for a sturdy, simple wooden pump and ordered his carpenters to build him four of them. They were ready within forty-eight hours. Shinkle tied up his powerful tugboat Champion No. 1 next to the pumps, and Roebling connected them with chains to the tug’s engines. It worked: the makeshift machinery easily flushed away the mud and silt. By the end of November the foundation was finished.
WORK STOPPED FOR the winter on Christmas Eve. Roebling went home to Trenton, New Jersey (where, in March, he wrote a letter to Horace Greeley suggesting “a wire suspension bridge crossing the East River”), and returned the following May. All the next summer, amid the clang and screech of the hoisting engines, the piers took shape. For the lower courses of masonry Roebling picked a native sandstone whose high petroleum content “promised a greater resistance to the action of the water.” The great, rough-cut blocks, he noted approvingly, gave the towers “a massive look quite suitable to their function. ”
At last all was going well with the bridge; this time it was the country that ran into trouble. The terrible financial panic of 1857 broke in August. The bridge company ran out of money. Roebling went home to try to save his wire-rope business.
Panic was followed by war. In the summer of 1862 Kirby Smith marched on Cincinnati with twelve thousand Confederate soldiers. Gen. Lew Wallace, who had the unenviable job of defending the city with volunteers, planned to make his stand south of Covington. This meant getting thousands of men across the river. A resourceful local architect named Wesley Cameron managed to cobble together a pontoon bridge in a day and a half. It may have been an extraordinary feat, but as Wallace’s men picked their way across its bucking surface, they were taunted by the sight of the unfinished piers that stood nearby.
Smith never got to Cincinnati, but the populace had been badly shaken. Money came in. Roebling returned.
Although six years had passed since work ceased on the towers, the engineer found that not a single joint had washed away: the seasons of flood and neglect had left them untouched. Roebling went back to work. As usual there were difficulties. Labor was scarce and expensive; he was infuriated that his “Cincinnati wharf rats” were dissatisfied with their wages of $1.25 a day. Worse, the war had made American wire unavailable. He had to order the material for the bridge cables from England, even though it was fearfully expensive and had to be paid for in gold. But all in all, things went well. Summer of 1864 saw the completion of the anchorages, in whose limestone depths were embedded the immense eleven-ton anchor plates to which the ends of the cables would be fixed.
THE NEXT SPRING Roebling was joined by his son Washington, just released from the Union Army. The younger Roebling knew all about the project, of course, but actually seeing it was something else again. “The size and magnitude of this work,” he wrote, “far surpasses any expectations I had formed of it. It is the highest thing in this country; the towers are so high that a person’s neck aches looking up at them. It will take me a week to get used to the dimensions of everything around here. ” Himself a supremely able engineer, Washington came on the job as his father’s chief assistant. By the end of the summer the towers were finished; they stood 230 feet above the river, a little over a thousand feet apart.
On September 10 a flatboat put off from the Ohio shore playing out behind it a two-and-a-half-inch cable that dipped down to the craft’s stern from the top of the Cincinnati tower. As thousands of spectators watched, the rope was hoisted over the Covington tower. “A powerful tackle purchase … was attached to it,” Roebling’s master carpenter, E. F. Earrington, wrote, “and at a time when there was little passing of steamers, it was drawn out of the water, and up to its proper position, and made fast to each anchor pier. Number two [cable] was served in the same manner. After this the foot bridge was built, and there was communication established FOREVER!” This foot bridge, only twenty-seven inches wide, was a severe disappointment to one confused onlooker, who grumbled that “after all the talk about a fine bridge, it’s a very flimsy affair.”
With the flimsy affair in place, the cables could be spun. Powered by driving machinery on the Cincinnati anchorage, the light carrier wheels shuttled back and forth across the river from tower to tower, all day long, month after month, running out wire behind them. It took 10,360 crossings before the two cables were done. Each was over a foot in diameter, a powerful bundle of 5,180 one-eighth-inch parallel wires clamped into a circle and bound with a final wrapping of galvanized iron wire. Each weighed over a million pounds.
From these the riggers strung the suspenders, 303 pairs of them spaced five feet apart, and in September the wrought-iron floor beams were attached to them.
With the crucial stiffeners in place, the oak floor nearly finished, and track being laid for the horsecars that were just beginning to come into use, Amos Shinkle, who was now the president of the company, chose the first of December, 1866, for the opening. The day dawned mild and fair, and as the sun rose it was greeted by two brass twelve-pounders in the Newport Barracks rattling out a hundred-gun salute. Despite a local newspaper’s maternal caution to “go very warmly clad, as it is very cold out there, over the water, with a keenly cutting wintry wind whistling along the river,” 46,000 people swarmed over the bridge. The following day 120,000 crossed.
The official opening to traffic took place on New Year’s Day, 1867. This was a far more formal affair, with a regular parade made up of bands and prominent citizens and fine carriages and led by Amos Shinkle and John Roebling.
By that time the engineer was deeply absorbed in his East River bridge. It would be grander in all respects than its Midwestern prototype—its river span half again as long, twice as long overall. But Roebling would die with it barely under way, and the Cincinnati Bridge was the closest he ever came to seeing how his greatest design would turn out.
It was no comtemptible substitute. The largest suspension bridge in the world, and the finest, it was, as Shinkle said, “the wonder and admiration of all who cross it.”
It had cost $1,800,000, twice the original estimate, but Shinkle was delighted with it. When Roebling came with his bridge party three years later, and one of the members asked the coal merchant if the structure paid, Shinkle answered happily, “Yes, sir, handsomely. ” He went on to praise the man who built it and then offered the Eastern visitors some advice: “He is an extraordinary man and if you people in Brooklyn are wise you will interfere with his views just as little as possible. Give the old man his way and trust him.”