The Bridge
Page 4
He had his chance to find out when, in 1851, he received a commission to build a suspension bridge over Niagara Falls. This opportunity arose only because the original engineer had abandoned the project after a financial dispute with the bridge company— this engineer being a brilliant but wholly unpredictable and daring man named Charles Ellet. Ellet, when confronted with the problem of getting the first rope across Niagara, found the solution by offering five dollars to any boy who could fly a kite across it. Ellet later had a basket carrier made and he pulled himself over the rushing waters of Niagara to the other side; and next he did the same thing accompanied by his horse, as crowds standing on the cliffs screamed and some women fainted.
Things quieted down when Ellet left Niagara, but John Roebling, in his methodical way, got the job done. "Engineering," as Joseph Gies, an editor and bridge historian, wrote, "is the art of the efficient, and the success of an engineering project often may be measured by the absence of any dramatic history." In 1855, Roebling's 821-foot single span was finished, and on March 6 of that year a 568-ton train crossed it—the first train in history to cross a span sustained by wire cables. The success quickly led Roebling to other bridge commissions, and in 1867 he started his greatest task, the Brooklyn Bridge.
It would take thirteen years to complete the Brooklyn Bridge, and both John Roebling and his son would be its victims. One summer morning in 1869, while standing on a pier off Manhattan, surveying the location of one of the towers, and paying no attention to the docking ferryboat that was about to bump into the pier, John Roebling suddenly had his foot caught and crushed between the pier floor and piles; tetanus set in, and two weeks later, at the age of sixty-three, he died.
At the death of his father, Washington Roebling, then thirty-two years old and the chief engineering assistant for the bridge, took over the job. Roebling had previously supervised the construction of other bridges that his father had designed, and had served as an engineering officer for the Union Army during the Civil War. During the war he had also been one of General Grant's airborne spies, ascending in a balloon to watch the movement of Lee's army during its invasion of Pennsylvania.
When he took over the building of the Brooklyn Bridge, Washington Roebling decided that since the bridge's tower foundations would have to be sunk forty-four feet into the East River on the Brooklyn side and seventy-six feet on the New York side, he would use pneumatic caissons—as James Eads had done a few years before with his bridge over the Mississippi. Roebling drove himself relentlessly, working in the caissons day and night and he finally collapsed. When he was carried up, he was paralyzed for life. He was then thirty-five years old.
But Washington Roebling, assisted by his wife, Emily, continued to direct the building of the bridge from his sickbed; he would watch the construction through field glasses while sitting at the window of his home on the Brooklyn shore; and then his wife— to whom he had taught the engineer's language, and who understood the problems involved—would carry his instructions to the superintendents on the bridge itself.
Washington Roebling was the first bridge engineer to use steel wire for his cables—it was lighter and stronger than the iron wire cables used by his father on the Niagara bridge—and he had every one of the 5,180 wires galvanized as a safeguard against rust. The first wire was drawn across the East River in 1877, and for the next twenty-six months, from one end of the bridge to the other, the small traveling wheels—looking like bicycle wheels with the tires missing—spun back and forth on pulleys, crossing the East River 10,360 times, each time bringing with them a double strand of wire which, when wrapped, would form the four cables that would hold up the center span of 1,595 feet and its two side spans of 930 feet each. This technique of spinning wire, and the use of a cowbell attached to each wheel to warn the men of its approaches, is still used today; it was used, in a more modern form, even by O. II. Ammann in the cable-spinning phase of his Verrazano-Narrows Bridge in the 1960s.
The Brooklyn Bridge was opened on May 24, 1883. Washington Roebling and his wife watched the celebrations from their windows through field glasses. It was a great day in New York— business was suspended, homes were draped with bunting, church bells rang out, steamships whistled. There was the thunder of guns from the forts in the harbor and from the Navy ships docked near the bridge, and finally, in open carriages, the dignitaries arrived. President Chester A. Arthur, New York's Governor Grover Cleveland, and the mayors of every city within several miles of New York arrived at the bridge. Later that night there was a procession in Brooklyn that led to Roebling's home, and he was congratulated in person by President Arthur.
To this day the Brooklyn Bridge has remained the most famous in America, and, until the Williamsburg Bridge was completed over the East River between Brooklyn and Manhattan in 1903, it was the world's longest suspension. In the great bridge boom of the twentieth century nineteen other suspension spans would surpass it—but none would cast a longer shadow. It has been praised by poets, admired by aesthetes, and sought by the suicidal. Its tower over the tenement roofs of the Lower East Side so electrified a young neighborhood boy named David Steinman that he became determined to emulate the Roeblings, and later he would become one of the world's great bridge designers; he alone, until his death in 1960, would challenge Ammann's dominance.
David Steinman at the age of fourteen had secured a pass from New York's Commissioner of Bridges to climb around the catwalks of the Williamsburg Bridge, then under construction, and he talked to bridge builders, took notes, and dreamed of the bridges he would someday build. In 1906, after graduating from City College in New York with the highest honors, he continued his engineering studies at Columbia, where, in 1911, he received his doctor's degree for his thesis on long-span bridges and foundations. Later he became consulting engineer on the design and construction of the Floriano-polis Bridge in Brazil, the Mount Hope Bridge in Rhode Island, the Grand Mere in Quebec, the Henry Hudson arch bridge in New York. It was Dr. David Steinman who was called upon to renovate the Brooklyn Bridge in 1948, and it was he who was selected over Ammann to build the Mackinac Bridge—although it was Ammann who emerged with the Verrazano-Narrows commission, the bridge that Steinman had dreamed of building.
The two men were never close as friends, possibly because they were too close in other ways. Both had been assistants in their earlier days to the late Gustav Lindenthal, designer of the Hell Gate and the Queensboro bridges in New York, and the two men were inevitably compared. They shared ambition and vanity, and yet possessed dissimilar personalities. Steinman was a colorfully blunt product of New York, a man who relished publicity and controversy, and who wrote poetry and had published books. Ammann was a stiff, formal Swiss gentleman, well born and distant. But that they were to be lifelong competitors was inevitable, for the bridge business thrives on competition; it exists on every level. There is competition between steel corporations as they bid for each job, and there is competition between even the lowliest apprentices in the work gangs. All the gangs—the riveters, the steel connectors, the cable spinners— battle throughout the construction of every bridge to see who can do the most work, and later in bars there is competition to see who can drink the most, brag the most. But here, on the lower level, among the bridge workers, the rivalry is clear and open; on the higher level, among the engineers, it is more secret and subtle.
Some engineers quietly go through life envying one another, some quietly prey on others' failures. Every time there is a bridge disaster, engineers who are unaffiliated with its construction flock to the site of the bridge and try to determine the reason for the failure. Then, quietly, they return to their own plans, armed with the knowledge of the disaster, and patch up their own bridges, hoping to prevent the same thing. This is as it should be. But it does not belie the truth of the competition. When a bridge fails, the engineer who designed it is as good as dead. In the bridge business, on every level, there is an endless battle to stay alive—and no one has stayed alive longer than
O. H. Ammann.
Ammann was among the engineers who, in 1907, investigated the collapse of a cantilever bridge over the St. Lawrence River near Quebec. Eighty-six workmen, many of them Indians, who were just learning the high-construction business then, fell with the bridge, and seventy-five drowned. The engineer whose career ended with his failure was Theodore Cooper, one of America's most noted engineers—the same man who had been so lucky years before when, after falling one hundred feet into the Mississippi River while working on James Eads' bridge, not only survived but went back to work the same day.
But now, in 1907, it was the opinion of most engineers that Theodore Cooper did not know enough about the stresses involved in the cantilever bridge. None of them did. There is no way to know enough about bridge failure until enough bridges have failed. "This bridge failed because it was not strong enough," one engineer, C. C. Schneider, quipped to the others. Then they all returned to their own bridges, or to their plans for bridges, to see if they too had made miscalculations.
One bridge that perhaps was saved in this manner was Gustav Lindenthal's Queensboro Bridge, which was then approaching completion over the East River in Manhattan. After a re-examination, it was concluded that the Queensboro was inadequate to safely carry its intended load. So the four rapid-transit tracks that had been planned for the upper deck were reduced by two. The loss of the two tracks was compensated by the construction of a subway tunnel a block away from the bridge—the BMT tunnel at Sixtieth Street under the East River, built at an additional cost of $4,000,000.
In November of 1940, when the Tacoma Narrows Bridge fell into the waters of Puget Sound in the state of Washington, O. H. Ammann was again one of the engineers called in to help determine the cause. The engineer who caught the blame in this case was L. S. Moisseiff, a man with a fine reputation throughout the United States.
Moisseiff had been involved in the design of the Manhattan Bridge in New York, and had been the consulting engineer of the Ambassador Bridge in Detroit and the Golden Gate in California, among many others, and nobody had questioned him when he planned a lean, two-lane bridge that would stretch 2,800 feet over the waters of Puget Sound. True, it was a startlingly slim, fragile-looking bridge, but during this time there had been an aesthetic trend toward slimmer, sleeker, lovelier suspension bridges. This was the same trend that led David Steinman to paint his Mount Hope Bridge over Narragansett Bay a soft green color, and to have its cables strung with lights and approaches lined with evergreens and roses, costing an additional $70,000 for landscaping.
There was also a prewar trend toward economizing on the over-all cost of bridge construction, however, and one way to save money without spoiling the aesthetics—and supposedly without diminishing safety—was to shape the span and roadway floor with solid plate girders, not trusses that wind could easily pass through. And it was partially because of these solid girders that, on days when the wind beat hard against its solid mass of roadway, the Tacoma Narrows Bridge kicked up and down. But it never kicked too much, and the motorists, far from becoming alarmed, actually loved it, enjoyed riding over it. They knew that all bridges swayed a little in the wind—this bridge was just livelier, that was all, and they began calling it, affectionately, "Galloping Gertie."
Four months after it had opened—on November 7—with the wind between thirty-five and forty-two miles an hour, the bridge suddenly began to kick more than usual. Sometimes it would heave up and down as much as three feet. Bridge authorities decided to close the bridge to traffic; it was a wise decision, for later it began to twist wildly, rising on one side of its span, falling on the other, rising and falling sometimes as much as twenty-eight feet, tilting at a forty-five-degree angle in the wind. Finally, at 11 A.M., the main span ripped away from its suspenders and went crashing into Puget Sound.
The factors that led to the failure, the examining engineers deduced, were generally that the tall skinny bridge was too flexible and lacked the necessary stiffening girders; and also they spoke about a new factor that they had previously known very little about: "aerodynamic instability."
And soon, on other bridges, on bridges all over America and elsewhere, adjustments were made to compensate for the instability. The Golden Gate underwent alterations that cost more than $3,000,000. The very flexible Bronx-Whitestone Bridge in New York, which Leon Moisseiff had designed—with O. H. Ammann directing the planning and construction—had holes punched into its plate girders and had trusses added. Several other bridges that formerly had been slim and frail now became sturdier with trusses, and twenty years later, when Ammann was creating the Verrazano-Narrows Bridge, the Tacoma lesson lived on. Though the lower second deck on the Verrazano-Narrows was not yet needed, because the anticipated traffic could easily be accommodated by the six-lane upper deck, Ammann made plans for the second deck to go on right away—something he hadn't done in 1930 with his George Washington Bridge. The six-lane lower deck of the Verrazano will probably be without an automobile passenger for the next ten years, but the big bridge will be more rigid from its opening day.
After the Tacoma incident, Moisseiff's talents were no longer in demand. He never tried to pass off any of the blame on other engineers or the financiers; he accepted his decline quietly, though finding little solace in the fact that with his demise as an influential designer of bridges the world of engineering knowledge was expanded and bigger bridges were planned, bringing renown to others.
And so some engineers, like Leon Moisseiff and Theodore Cooper, go down with their bridges. Others, like Ammann and Steinman, remain high and mighty. But O. H. Ammann is not fooled by his fate.
One day, after he had completed his design on the Verrazano-Narrows Bridge, he mused aloud in his New York apartment, on the thirty-second floor of the Hotel Carlyle, that one reason he has experienced no tragedy with his bridges is that he has been blessed with good fortune.
"I have been lucky," he said, quietly.
"Lucky!" snapped his wife, who attributes his success solely to his superior mind.
"Lucky," he repeated, silencing her with his soft, hard tone of authority.
CHAPTER FOUR
PUNKS AND
PUSHERS
Building a bridge is like combat; the language is of the barracks, and the men are organized along the lines of the noncommissioned officers' caste. At the very bottom, comparable to the Army recruit, are the apprentices—called "punks." They climb catwalks with buckets of bolts, learn through observation and turns on the tools, occasionally are sent down for coffee and water, seldom hear thanks. Within two or three years, most punks have become full-fledged bridgemen, qualified to heat, catch, or drive rivets; to raise, weld, or connect steel—but it is the last job, connecting the steel, that most captures their fancy. The steel connectors stand highest on the bridge, their sweat taking minutes to hit the ground, and when the derricks hoist up new steel, the connectors reach out and grab it with their hands, swing it into position, bang it with bolts and mallets, link it temporarily to the steel already in place, and leave the rest to the riveting gangs.
Connecting steel is the closest thing to aerial art, except the men must build a new sky stage for each show, and that is what makes it so dangerous—that and the fact that young connectors sometimes like to grandstand a bit, like to show the old men how it is done, and so they sometimes swing on the cables too much, or stand on unconnected steel, or run across narrow beams on windy days instead of straddling as they should—and sometimes they get so daring they die.
Once the steel is in place, riveting gangs move in to make it permanent. The fast, four-man riveting gangs are wondrous to watch. They toss rivets around as gracefully as infielders, driving in more than a thousand a day, each man knowing the others' moves, some having traveled together for years as a team. One man is called the "heater," and he sweats on the bridge all day over a kind of barbecue pit of flaming coal, cooking rivets until they are red— but not so red that they will buckle or blister. The heater must be a good co
ok, a chef, must think he is cooking sausages not rivets, because the other three men in the riveting gang are very particular people.
Once the rivet is red, but not too red, the heater tong-tosses it fifty, or sixty, or seventy feet, a perfect strike to the "catcher," who snares it out of the air with his metal mitt. Then the catcher relays the rivet to the third man, who stands nearby and is called the "busker-up"—and who, with a long cylindrical tool named after the anatomical pride of a stud horse, bucks the rivet into the prescribed hole and holds it there while the fourth man, the riveter, moves in from the other side and begins to rattle his gun against the rivet's front end until the soft tip of the rivet has been flattened and made round and full against the hole. When the rivet cools, it is as permanent as the bridge itself.
Each gang—whether it be a riveting gang, connecting gang or raising gang—is under the direct supervision of a foreman called a "pusher." (One night in a Brooklyn bar, an Indian pusher named Mike Tarbell was arrested by two plainclothes men who had overheard his occupation, and Tarbell was to spend three days in court and lose $175 in wages before convincing the judge that he was not a pusher of dope, only of bridgemen.)
The pusher, like an Army corporal who is bucking for sergeant, drives his gang to be the best, the fastest, because he knows that along the bridge other pushers are doing the same thing. They all know that the bridge company officials keep daily records of the productivity of each gang. The officials know which gang lifted the most steel, drove the most rivets, spun the most cable—and if the pusher is ambitious, wants to be promoted someday to a better job on the bridge, pushing is the only way.