How Did They Build the Bridge That Changed the History of Bridge Building in America — and the World? | This Is How Our Lives Were Designed

Its structure, its methods, its materials: everything about it was new. More than a hundred years ago, the Brooklyn Bridge, sitting on New York's East River, proclaimed the power of technology and industry.

"When completed according to my design, it will not only be the greatest bridge in existence, but it will be the greatest engineering work of this state, and of this age. Its most conspicuous feature, the great towers, will serve as landmarks joining the two cities, and will be ranked as national historic sites. A great work of art, a specimen of advanced bridge engineering, this structure will forever testify to the vitality, the wealth and the enterprise of this society." John Augustus Roebling wrote that in 1867, in the tone he always used, the one in which nothing seemed impossible.

He was talking about the Brooklyn Bridge: then the longest and most expensive suspension bridge in the world, the first link between Brooklyn and Manhattan, the bridge that made a new New York, the bridge that carried the city's ambition to become the commercial center of the world.

The Proposal

"New York and Brooklyn must be united," wrote Horace Greeley, founder of the New-York Tribune, in 1849.

The idea of throwing a bridge across the East River to join the two cities had lived in the American mind for a long time. The earliest formal proposal on record dates to 1800, and after that one East River bridge scheme followed another, year after year. None of them was built.

The main obstacle was the East River lying between the two cities. It is a tidal strait: back then the current ran fast and the bed was strewn with rocks. It was also Manhattan's great gateway for traffic, and one of the busiest shipping lanes in the world. Every winter the river froze over and traffic between New York and Manhattan stopped.

In 1867, in Albany, New York, lawmakers voted on a charter that gave The Bridge Company the right to build and run a bridge over the East River. The charter said nothing about how to build it. It said only that the bridge should charge tolls, carry enough railings, stay lit all night, and be finished by January 1, 1870.

A month later the charter became law, and John Roebling was appointed its engineer.

American elevated steel construction has had many heroes, but the Roeblings — yes, not only John, but his son and even his daughter-in-law — are the strangest combination of them all. A studious, questioning young German trained in civil engineering, John Roebling could do nothing in the Prussia of 1831 but build railways and roads, so he emigrated to the United States and started an unusual business: twisting iron wire into fiber rope, to cure the hemp towlines that hauled boats of their habit of snapping. That is how John Roebling came to own the largest steel-wire and cable works in the world.

But what he wanted most was to build suspension bridges. He had seen small designs as a student in Germany, and in 1851 he got to carry out a large one at Niagara Falls, sending a train across a span hung from wire cable for the first time in human history. All of this is why he was made the designer of the Brooklyn Bridge.

Late-19th-century America — what Mark Twain called an age of extravagance — was also a famously rotten one, the heyday of political bribes, crooked contracts and double standards. If you were simple-minded and adrift, New York was a good place to lose your illusions. John Roebling, a Jew, plainly was neither. He was clever and ambitious, and he knew how to deal with officials and businessmen.

The Brooklyn Bridge took 13 years to build in the end, and both John Roebling and his son paid a price for it.

A Giant Caisson Foundation Like Nothing Built Before

Roebling set to work on his great project full of confidence. Then, on a survey trip to place the towers, a boat struck the dock and crushed one of his feet between the dock floor and a mooring pile. The wound turned to tetanus. He refused his doctors and put his faith in an old water cure. He died two months later, at 63.

The project did not stop. John Roebling's son, Washington Roebling, talked the nervous shareholders round and became chief engineer of the Brooklyn Bridge.

In John Roebling's design, two towers carried the whole bridge. They had to be strong enough to hold its weight, and tall enough to leave the river's heavy traffic alone.

The first job was a caisson that men could work in underwater. Washington had seen small caissons in Europe, but the one the Brooklyn Bridge needed was bigger than any European bridge had used: it covered more ground than four tennis courts and stood three stories high. Roebling had it built in a shipyard, because he believed only shipwrights knew how to make timber watertight.

Once finished, the caisson was launched like a ship and towed to the spot where the pier would stand. After the launch, ten courses of heavy planking were laid on its roof. Inside, men dug sand, gravel and rock out of the chamber with shovels and picks, and the caisson sank; above, other men built the pier on its roof, and the weight of the granite pushed it down further, until it touched the riverbed. Cement was then poured in to make a solid foundation.

Roebling chose tough, water-resistant yellow pine, and coated the caisson inside and out with a waterproof layer six feet thick. Six "shafts" connected it to the world outside: two cylindrical air locks moved compressed air in and out; a supply shaft carried the men down to work, and later carried the cement once the digging was done; and a water shaft ran from the floor of the caisson all the way up above the surface, taking out sand, gravel and rock. The clever thing about the water shaft was that it not only "locked in" the air but also let the pressure inside the caisson be measured.

The huge, precise caisson design was a great deal less wonderful for the men who had to work inside it.

The pressure of the East River, the heat, the compressed air, the foul smell mixed with the din of drills and shovels: in conditions like that a man underwater could work only four hours a day. Many of them often had trouble breathing; their eyes went red and bulged, their noses bled, they felt sick. Later came numbness and pain in the limbs, which took anywhere from a few days to a few weeks back on dry land to go away.

Even with working conditions out of purgatory, the Brooklyn Bridge site never ran short of hands. This was 19th-century America, and $2.10 for four hours (against $2.50 for eight hours on land) was enough to draw immigrant labor in crowds.

The foundation was far harder than anyone had imagined. It had to be dug out bit by bit, through a long and painful process. Not until 1871 were the towers of the Brooklyn Bridge finished.

The crew on the New York side of the river had worse luck. Their caisson kept going down — to 18 meters — and still found no rock. Two men died of the bends, one after the other. The site grew frightened; men kept leaving, and new immigrant laborers kept arriving, pulled in by the "generous" pay.

At 24 meters, a depth no bridge had ever reached, the crew struck rock as hard as cement and blunted every tool they had on it. Washington had to make a judgment: push on to bedrock and lose more men, or let the tower stand on packed sand.

He chose the sand, and had to carry the risk of being wrong. More than a hundred years later, the foundation still holds.

The bigger the job, the more people it draws in, and the more slips out of anyone's control. Workers' lapses started fires and let compressed air escape. Washington, who had caught the bends from his long stretches below the river, came out of those accidents worse than before, until he could no longer go to the site at all.

His wife, Emily Roebling, taught herself higher mathematics and engineering, and over the next 11 years helped him oversee the work, carrying the problems that came up on the bridge to him and his solutions back. Meanwhile the ailing Washington still watched the work go up every day from his home in New York, through a field telescope.

Next to the grind below water, building the towers above it was easy. Every day three cranes, driven by steam engines, lifted great blocks of stone — limestone and granite — into the air and set them one by one. Most American buildings then were no more than five stories; the towers of the Brooklyn Bridge rose the height of 25. Gothic, and head and shoulders above everything else in sight, they were a stirring thing to look at.

The First Use of Steel Cable

The arrival of steel gave the Brooklyn Bridge another first.

The towers carry four enormous main cables between New York and Brooklyn. Each main cable is 0.4 meters across and about 5,633 meters long, bound together from 19 strands, each strand spun from 278 steel wires, each wire about as thick as a pencil. The Brooklyn Bridge was the first to use steel cable; before it, bridges were hung from iron chains, and sometimes even from rope.

To settle people's doubts, when the first cable was strung the mechanical engineer Farrington rode across it in a boatswain's chair, becoming the first man to cross the bridge.

Accidents came anyway. The fault lay not with the steel, but with the men behind the wire.

In 1871 William M. Tweed — "Boss" Tweed, head of Tammany Hall, the political machine of the Democratic Party, and also a major holder of bridge stock and the board member in charge of the project's money — was exposed in a bribery scandal and jailed. By his own testimony, to win a $1.5 million bond issue and profit from the bridge, Tweed had paid city aldermen as much as $65,000. The public was let down by the government and the company all over again.

Because John Roebling had been so exacting about quality while he lived, John A. Roebling's Sons Company could make the best steel cable in the business. But attacks over conflict of interest kept the Roebling firm out of the work. The board, watching its budget, handed the cable contract to a Brooklyn company run by J. Lloyd Haigh. Everyone in the trade knew Haigh for a dishonest man, and rotten wire went into the main cables. In June 1878 a snapping wire threw a worker off the structure; two men died and three were badly hurt.

The contract went back to John A. Roebling's Sons Company in the end, but the bad wire already buried in the main cables could not be pulled out. Washington had no choice but to add 150 extra wires to each main cable to keep the work sound. The anchorages that hold the four main cables down weigh 54,431 tons apiece — as if 12,000 elephants were pulling on them. On top of that, Washington ran diagonal stays through the suspenders that carry the deck, making the roadway six times stronger than his father had planned.

The "last straw" came in the tenth year of building. The company supplying material for the deck kept failing to deliver, and after all the scandals and accidents the public seemed to run out of patience. Rumors spread that Washington was sicker, that he had lost his mind, and for a while opinion turned on him.

A motion to replace the chief engineer reached the board's agenda — a heavy blow to a family that had given the bridge more than a decade. On top of inspecting the work, Emily Roebling set about killing the rumors and keeping the chief engineer's post in Roebling hands. She became the first woman to speak before the American Society of Civil Engineers, and she saved her husband's dignity.

Completion

Through tangled fights over interests and one mishap after another, the Brooklyn Bridge was finished at last in 1883, after 13 years and 27 lives, among them that of the chief engineer, John Roebling.

President Chester A. Arthur and New York's mayor, Franklin Edson, walked across to meet Brooklyn's mayor, Seth Low, on the far side. Thousands came to the opening ceremony and watched the moment under fireworks and cannon salutes.

The Roeblings were lucky. (Yes — luck, in the words of another famous American bridge builder, Othmar Ammann, was the most important thing in his career. Ammann designed the famous Verrazzano-Narrows Bridge.)

The Brooklyn Bridge never fell down. Collapses were common in the 19th century and well into the 20th, and their chief designers were usually celebrated engineers: Theodore Cooper, for instance, who designed the bridge over the St. Lawrence River near Quebec. Eighty-six workers went into the river with it, and 75 of them drowned.

Many engineers look in other men's failures for clues to the weak points in their own designs. After every collapse like that, engineers with no part in the bridge would crowd to the site and try to work out the cause. But for the bridge that fell, the career of the man who designed it was over.

In Roebling's design, the walkways on either side of the deck sit above the carriage road and the rail tracks, so that people can take in the view the bridge gives them. As David McCullough wrote, "The roadway and the tracks were for the daily traffic, but the walkway was for the soul."

Tall towers, elegant arches, crossing cables and stays — and, thanks to the invention of the electric light, the Brooklyn Bridge was also the first bridge lit by electricity, the first thing on the East River worth looking at after dark.

To this day the Brooklyn Bridge is still one of the most famous bridges in America. Until 1903, when the Williamsburg Bridge went up on the East River between the Brooklyn Bridge and Manhattan, it had the longest suspension span in the world. As the writer Gay Talese put it: "It has always been praised by poets, envied by aesthetes, and loved by suicides."

Cover image and images in the article are from: Archdaily, Engineer's Journal, Motherboard, Wiki