- Historic Sites
Not The Brooklyn Bridge
It was built by Roebling, connects two cities, is a landmark of American engineering, and looks just like it but is…
October/november 1983 | Volume 34, Issue 6
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.