The Brooklyn Bridge, begun in 1869 and opened to the public in 1883, was an unprecedented construction; truly the “8th Wonder of the World” in its day—and perhaps it still is. It was the first suspension bridge with cables made of steel, rather than iron. It was a bridge with a span that would not be significantly surpassed for 50 years—not until the construction of the George Washington Bridge, over the Hudson River. And it was a bridge built using a dangerous new technology, one that Washington Roebling pioneered—at great cost to himself.
He had taken over the project after the death of his father, John Roebling, a famous engineer who had bridged Niagara Falls, and the Ohio River in Cincinnati. At the time, many people thought that to bridge the East River was impossible. But if anyone should be the man to accomplish the feat, John Roebling was that man. And then, one day, in the summer of 1869, before any real work had been started, before very many plans had been made, John Roebling had what seemed to be a minor accident down by the river. Before two weeks had passed, however, he was dead—a horrible death, from tetanus—and it was left to his son to take over the work. Washington, just 32 years old at the time, had built bridges for the Union Army during his service throughout the Civil War. He had then supervised work on his father’s Covington-Cincinnati Bridge, known today as the John A. Roebling Suspension Bridge. Yet for all his expertise, Washington had been his father’s lieutenant. But now John Roebling was no more, and it was Washington who would build the bridge his father had envisioned.
The most treacherous work was the sinking of the caissons—great wooden chambers launched like upside-down ships and settled on the river’s bed. Inside these chambers, hundreds of men dug out sand and stone while blocks of granite and limestone built the great tower above. The river is kept out by compressed air, pumped down through shafts in the chamber’s room; as the men dig down towards bedrock, additional shafts allow waste material to be taken out. The roof of the caisson is made of layer upon layer of dense pitch pine. What’s it like to work in compressed air? It’s like diving under the ocean. Come up too fast from the dense atmosphere and you get very sick indeed. In the 21st century this is called decompression sickness, but in the 19th century when, thanks to projects such as the building of the Brooklyn Bridge its symptoms began to appear, it was called “caisson disease.” Nitrogen bubbles in the blood cause agonizing pain, paralysis—and sometimes, death.
Meanwhile, up in the daylight, huge blocks of stone, weighing as much as eight tons, were hauled to the top of the tower on derricks supported by iron guy ropes; one day in October one of the guys snapped under the weight of its load, sending stone and derrick crashing down. [The bridge’s masonry is composed of granite and limestone. The towers are mostly limestone below the water, and granite above. The anchorages are mostly limestone—with 650 cubic yards of granite blocks placed on top of the anchor plates.]
“The accident we had yesterday was very dreadful,” Washington wrote to his younger brother Ferdinand. “Three men are dead, and the rest are so scared that you cannot get them to work again. Two derricks are completely destroyed, and other damage done which $20,000 will not cover. Stone setting will be stopped for the season.” But such things, as Washington knew, only happened if they had a right to happen: “It was all the fault of the Trenton blacksmith. The weld in the handle of the socket was merely a cold shut hammered over on the outside to hide it. No part of the iron was welded, and the great wonder is that it did not break long before. The strain on it was only 1/5th of what the iron should bear if it had been sound.”
And in the Roebling archives is a remarkable document, a note written first in pencil, crossed out, and rewritten in ink beneath in a hand that is still almost completely legible, no matter in how much haste this aide-mémoire was composed. “Accidents,” is the heading, and it begins with one word: “Fire.” Throughout his life, Washington Roebling would write on any available scrap of paper, on the back of old stationery, on small slips found in the backs of drawers. Here is one, evidence both of attention and exhaustion, of the need to keep every detail in his mind. It reads, now, almost like a kind of urgent poetry. “Several small Fires. Leaks in seams—a caulking of oakum catches easily—some easily put out. One over shoe . . . slightly serious—5' wide and 6" burnt away—had to flood caisson—water entered easily as pressure was let off—only 3 courses masonry on at the time—water pumped out—4 hours by air.
“Increased watchfulness henceforth. Water supply from outside getting scarcer, finally all cut off—Necessity of flooding caisson from outside if fire got started. Danger of doing it. Increased caution—water pipes, hose—steam hose from outside. Fire on night of Dec 1 . . . Candle, pointing with cement. Bad place, would not be seen. Burnt appearance—living coals . . . no smoke—amount of water applied . . . Above frame no chance to stop up leaks. Steam no good—apparently out. Digging out—boring commenced— No fire at first, smell outside—danger of letting out air, settling of caisson—over night. Risks. Ultimate decision. Boats, 38 streams, 5 hours time—contents = 1,350,000 gallons—Fire not out until roof reached.
“Flooded how long—water pumped out in 6 hours—forced out over water shafts . . . smell, suspicion of fire—reasons against it—How long it lasted—heat in wood—no air bubbles.”
On the timber roof of the caisson the whole structure rested: and then, that timber caught fire. Everything could have been lost thanks to a moment’s carelessness. “The immediate cause of the fire must be owing to a candle held in the right hand of the man who had his coat or dinner in a candlebox which was nailed up over the door close to the roof. He could only reach the box by stepping up on a frame brace, when he would hold a candle with his right hand and reach into the box with his left. He must have held the candle there at least a minute,” Washington surmised. The man, the Brooklyn Daily Eagle reported, was called McDonald; once he had seen the hole burned through the wood, he filled it with plaster “to conceal his blunder”; he soon after disappeared, “and has not been seen since.” But in the oxygen-rich atmosphere of the caisson, the wood behind the patch job kept burning, “living coals” as Washington described them. Buckets of water, carbon dioxide from fire extinguishers had no effect; a “desperate remedy” had to be tried. There was nothing for it but to flood the caisson from above; but such a plan was more than just risky. “If the air should all be out before the water had reached the roof, the result would be a sudden drop of the caisson, and the destruction of all supports by the weight of twenty-eight thousand tons, besides running the risk of causing the caisson to leak so badly as to render its reinflation impossible . . .”
Now the hard work, and more crucially the weight of responsibility, began to take its toll on Washington. “All these considerations had to be carefully weighed, and the risks looked at from both sides, before giving the order to flood it. There was no intelligent mind to consult with, as all of my assistants make it a point to live 3 miles away from this work so as not to be on hand in case of an emergency,” he wrote with not a little bitterness. “In the mean time I had been down in the Caisson for 7 hours and began to experience that peculiar numb feeling in the small of the back & lower limbs which precedes paralysis . . .” Fireboats were called; 1,350,000 gallons of water were poured down through the caisson’s shafts, and the caisson remained flooded for two and a half days; it settled by two inches. When the water was eventually pumped out, the damage was painstakingly repaired: at first cement was pumped into the blackened caverns left by the blaze, but this turned out to be a bad mistake when it was discovered that the wood had burned into a layer of soft, friable charcoal, which would have to be cleared out and replaced with new wood. The work of digging out the cement took 18 carpenters, working day and night, two months. “The work was extremely disagreeable and un-healthy,” Washington wrote. “Men had to lie for hours in confined spots, without room to turn, and breathing a foul mixture of hot candle-smoke and cement-dust combined with powdered charcoal, and under pressure at that, the temperature being eighty degrees.” Eleven courses of timber had been damaged; more pine was forced into the breaches, and more cement, once the charcoal had been cleared away; iron straps were bolted to the chamber’s roof.
After those seven hours down in the caisson, Washington had to be taken home and “rubbed for an hour on the spine with salt & whiskey.” He had tried to rest, but at any moment expected “to hear the door bell ring with a message that the Caisson was burning yet”; and indeed that message had come. “It seems there was the usual delay in executing my orders (all ordinary human beings, including myself”—those two words inserted above with a carat—“delight in delays and procrastination).”
He recovered enough, clearly, to write up his notes; whether it was the salt and whiskey that did the trick, or simply being away from the caisson, we don’t know. We don’t know if his wife, Emily, tended to him, or how much he would have seen of his three-year-old son. Here, however, is his quality of practical rigor, “the rigor of the open world where uncertainty is profound.” The construction of the caisson, the blowouts, the fire—the most careful plans could be made, and yet every day brought new challenges and new uncertainties. Washington Roebling might call all this simply doing his job—but considering the strength of mind and feeling required is what draws us into that Hicks Street room, still scented with smoke and whiskey, to find Washington back at his desk. There were still no end of solutions to be found.
From Chief Engineer: Washington Roebling, The Man Who Built the Brooklyn Bridge, copyright 2017 Erica Wagner. Used by permission of Bloomsbury Publishing.