Roebling was one of those trapped inside the caisson at the time. The noise, he said, was so deafening that no voice could be heard. Water was pouring in from the water shafts. The lights went out. The air, he said, was full of a dense, impenetrable mist. Men were stumbling all over one another, running in terror, smashing into pillars, tripping and falling in the pitch-darkness, nobody sure where he was going.
In an instant the water was up to their knees. The river had broken in, they all thought.
“I was in a remote part of the caisson at the time,” Roebling wrote, “half a minute elapsed before I realized what was occurring and had groped my way to the supply shaft, where the air was blowing out. Here I joined several firemen in scraping away the heaps of gravel and large stones lying under the shaft, which prevented the lower door from being closed.” It took from two to three minutes for them to clear the door. Then they had it shut and everything was all over. Fifteen minutes later the pressure was restored.
Roebling had kept his head under the most nightmarish conditions, and when nobody else had. He had analyzed the situation in an instant and moved swiftly to put a stop to it. In the eyes of many, it was as commendable a demonstration of cool command as anything he had done on a Civil War battlefield.
Later, in his formal report to the directors, he wrote:
The question naturally arises, what would have been the result if water had entered the caisson as rapidly as the air escaped? The experience here showed that the confusion, the darkness and other obstacles were sufficient to prevent the majority of the men from making their escape by the air-locks…Now it so happens that the supply shafts project two feet below the roof into the air chamber; as soon, therefore, as the water reaches the bottom of the shaft it will instantly rise in it, forming a column of balance and checking the further escape of air. The remaining two feet would form a breathing space sufficient for the men to live, and even if the rush of water were to reduce this space to one foot, there would be enough left to save all hands who retained sufficient presence of mind.
It is not known whether he had realized this before the supply shaft blew out.
Again, as after the “Great Blowout,” an examination was made to determine what effect the impact of sudden weight had had upon various internal supports and particularly on the new brick pillars. By the time Roebling and the others got the supply shaft door closed, pressure in the chamber had dropped from seventeen to four pounds. He reckoned, therefore, that for several minutes the weight on the pillars was twelve tons to the square foot. Still, they showed no signs of strain, which was the clearest demonstration possible of their capacity to bear up under the load they were designed for and proof certainly that Roebling had been right to put them in. More important, the subsoil beneath the pillars, on which the bridge was to bear, had also withstood this same tremendous pressure.
But Roebling would be granted precious little time to take pride in the way things were being handled. Work on the masonry above had stopped because of the weather. Eleven courses of stone had been laid up within a wooden cofferdam, the top of the stonework being about even with the river at high tide. But the people manning the dump carts were still about, along with a number of others who looked after this or that piece of equipment, and they had begun noticing a strong smell of turpentine that seemed to be coming from air bubbles being forced up through the caisson. Large deposits of frothy reddish-brown pyrolignic acid, or “wood vinegar,” as the men called it, had also been found, indicating, as Roebling said, “that a destructive distillation of wood had been going on.”
Acting on what he called very unpleasant suspicions, Roebling quietly ordered Farrington to start drilling into the roof again. About two hundred borings were made to determine for everyone’s satisfaction just how extensive was the internal damage from the fire.
Most of it seemed to be confined to the third and fourth courses of timber, as had been expected, but as nobody had imagined, it also extended out laterally in every direction, in some places as much as fifty feet, or about five times farther than anyone had judged earlier. Equally disturbing was the discovery that the compressed air was rushing out of every bore hole, which meant that any attempt to cut into the roof to make repairs would result in an enormous drain on pressure.
Roebling decided, however, that if the air chamber were filled in with concrete around the edges, the pressure might now be released entirely with no harm. He had decided, in other words, that he could trust the brick pillars to support everything. So if maintaining pressure was no longer the vital concern, then holes as large as need be could be cut overhead and the damaged areas seen to properly.
Still, as he wrote, “It was very desirable…to gain time and do as much as possible at once, while air pressure was yet on.” It would be necessary therefore to plug the boreholes and at the same time compensate somehow for the honeycomb of charred pine they all pictured overhead.
Accordingly cement grout was injected into all two hundred boreholes. It was no easy task and it took quite some time. Roebling had a cylinder and piston fixed to a quarter-inch pipe. The cylinder was filled with liquid cement, placed under a borehole, the pipe inserted, then the cement forced up the hole by a screw jack. The technique worked well for the most part. The cement could be forced a good ten feet into the timber and appeared to spread out laterally to some distance. But the moment it met any resistance, all the water would be squeezed out, and to budge the charge another inch became impossible. So a thinner mixture was tried and it was found that the suction of compressed air alone, through the holes, was enough to draw this up the pipe and into the timberwork.
By the time they were finished, six hundred cubic feet of cement had been pumped into the caisson roof. The leaks had been stopped and a number of new boreholes in the area of the trouble failed to reveal a single place without its own vein of hardened cement. “We already flattered ourselves that this filling might answer every purpose…” Roebling wrote.
But just to be sure, he had a great hole, six feet across, cut into the roof through five layers of timber, directly over the spot where the fire had originated. And by opening up the roof this way they discovered that they had been exceedingly proficient in their work and that it had been a great mistake. The cement had indeed filled every crack and crevice, but most of the timber beneath the cement was covered with a layer of soft, brittle charcoal, anywhere from one to three inches thick.
It was a crushing revelation. It meant that every last bit of the cement put in so laboriously would have to come out, and any charcoal there was would have to be found and scraped away. There was no other alternative Roebling said. The caisson roof, the timber platform upon which the bridge tower would stand, had to be absolutely, permanently solid. He could take no chances on that. He could no more let it go this way then he could launch a ship with rotten timbers.
The immense, painstaking job of restoration that followed took a force of eighteen carpenters three full months to complete, working night and day. It was like gigantic dentistry, as someone said. To say that the work was extremely disagreeable, as Roebling did in his report to the Board of Directors, was to greatly understate the situation.
Not until the cement was all chopped out did anyone realize the full extent of the fire. Instead of one opening into the roof, five had to be cut, slowly, laboriously, each one three to four feet square and five feet deep or more. Above the original opening it was found that the fire had not only turned the third and fourth courses of timber to charcoal, but it had burned right through the sheet tin between courses four and five, destroyed the fifth course and made a start on the sixth. To judge by the traces it left, the fire had advanced mainly as a slow, intense charring that expanded equally in all directions. But in numerous places it had been strangely erratic, due no doubt to the multitude of leaks that fanned it. Roebling noted, for example, that a single 12-by-12 timber would be burned away for thirty feet, while one just like it directly alongside would be
untouched. And since the courses had been laid up at right angles to one another, the fire had had opportunity to branch off in a zigzag pattern, jumping from one timber to another, heading off left or right, up or down.
Damaged timbers were carefully scraped clean and all jagged edges were squared off with chisels. Every foot of burned wood was cut out. New cement was rammed into the smaller places, while new timber was cut to size (in lengths of eight to ten feet usually), rammed into all the larger openings with a screw jack, and securely bolted.
The burned channels that wandered laterally between the big vertical openings were generally about two by three feet in dimension. All such channels had to be gouged out by hand, then filled in in the same manner. The men worked like coal miners along such veins, inching forward on their backs or sides, with barely enough room to move, digging out charcoal instead of coal, imprisoned in a mountain of wood instead of earth. For hours at a time a man would be confined to a single spot, unable to turn around, his only light a little bull’s-eye lantern, and breathing candle smoke, cement dust, and powdered charcoal. Because the air pressure had been greatly reduced by the openings that had been cut, the ventilation was dreadful and the heat remained near 90 degrees.
“After everything was filled up solid,” Roebling wrote, “a number of five-foot bolts were driven up from below so as to unite both the old and new timber into a compact body.” He also had forty iron straps bolted against the roof from below, and inside the air chamber, directly under the line of the fire, he had great square blocks of traprock set in the concrete that was being put down over the rest of the chamber floor.
When the repairs were at last completed Roebling reminded everyone that there were still eleven perfectly sound layers of timber above the first four. And in his final report he stated, “From the faithful manner in which the work was done it is certain that the burnt district is fully as strong, if not stronger than the rest of the caisson.” Most people believed him.
The fire and its aftermath had been a sobering experience. It had delayed the work two, possibly three months. With the payroll running about eleven thousand dollars every two weeks, this meant a loss of some fifty thousand dollars at least, on that score alone. The fire had done much to reinforce the arguments of the skeptics, of whom there were still plenty on both sides of the river. This said one New York paper was the “main mischief” of the whole unhappy affair. But it had also been a brutal physical and mental ordeal for many of the men, and for Roebling in particular, whose strength had never quite returned since the night he collapsed in the caisson. He was a changed man after that, his assistants would say later.
Had he decided early that night to flood the caisson, in spite of the boulders beneath the water shaft, then things might have gone differently. But if he ever speculated about that, it was only in private.
The last repairs were completed on March 6, 1871. Five days later the air chamber was completely filled with concrete. During the final few weeks of sinking the caisson, several fresh-water springs had been encountered, and now, much to everyone’s astonishment, the water came right up through six feet of concrete in such quantity that it filled the water shafts clear to the top. The water was perfectly fresh, without a trace of salt, so it was all coming from directly beneath the caisson. The shafts were drained, therefore, and they too were filled with concrete. The air locks were removed and these empty spaces were also filled with concrete.
So by mid-March the Brooklyn caisson was permanently in place. The hardest, most treacherous and uncertain part of the work, the sinking of the caissons, was half done. No lives had been lost, no one had been seriously injured. Every man on the engineering staff had proved himself worthy of the faith Roebling had in him, and none had quit.
Work on the Brooklyn side from here on would be of the sort everyone had been anticipating. There would be something actually to see now, to watch grow and change from one day to another. The Brooklyn tower, it was commonly said, would be the greatest structure in the world except for the Pyramids. “America has seen nothing like it,” Thomas Kinsella wrote on the editorial page of the Eagle. “Even Europe has no structure of such magnitude as this will be. The most famous cathedrals and castles of the historic Old World are but pygmies by the side of this great Brooklyn tower. And it is our own city which is to be forever famous for possessing this greatest architectural and engineering work of the continent, and of the age.”
Such grandeur was still several years off, everyone knew, but it was not so very difficult to picture. “Think of Trinity Church as big at the top of the steeple as at the ground,” said Kinsella, “and one solid mass all the way up, and we get some idea of what this great Brooklyn tower is to be…the fame of the Roeblings and the boast of Brooklyn forever will be that, where Nature gave no facilities for a suspension bridge, and seemed indeed to place a veto upon the idea in these low and shelving shores, the genius of the father designed, and the consummate inherited and acquired ability of the son executed, in spite of all obstacles, this most novel and unparalleled masterpiece….”
But not until June 5, when the Eagle published Washington Roebling’s annual report to the directors of the Bridge Company, did the people of Brooklyn and New York get a fair idea of what exactly had been accomplished to make the tower possible. Except for the flurry of excitement when the fire was discovered, almost nothing about the details of the work or the setbacks experienced inside the caisson had appeared in the newspapers. Roebling’s report filled seven and a half columns. It was straightforward, unadorned, and it was read with enormous interest. People were utterly astonished to learn all that had taken place beneath their very noses. “We are not partial to long official reports,” the Eagle said by way of introduction, “but this one is exceptional in the thrilling interest of the story.” Roebling was praised for his modesty by the editors and lauded for his own personal heroism in such a way that it seemed they too were realizing for the very first time the extent of what had happened down at the end of Fulton Street. In 1870, when the caisson was making its slow, tedious descent, the English translation of Jules Verne’s Twenty Thousand Leagues Under the Sea had appeared in America, with its adventures of the strange genius Captain Nemo. Now the Eagle wrote: “The adventures of Colonel Roebling and his twenty-five hundred men under the bed of the East River are as readable, as he tells them, as any story of romance which has issued from the imagination of the novelist.”
What Colonel Roebling and his men might run up against on their next descent was now, naturally, a matter of much popular interest. On one side of the river a tower of imperishable granite would be rising straight into the sunlight, while on the other side, mortal men would be descending beneath the tides and into the earth. It was quite a picture to keep in mind for anyone crossing the river to clerk in a countinghouse or sit the long day at a sewing machine.
11
The Past Catches Up
The spectacle is appalling. We live in an atmosphere of hypocrisy throughout.
—WALT WHITMAN,
Democratic Vistas
WHEN the New York caisson hit the water it made such a wave that several tugs standing close by were tossed about in a “very sportive manner” and two men in a rowboat, who had come in close for a better view, were immediately swamped and had to be rescued. Because of the comparatively shallow water in front of the Sixth Street launchways, the caisson had been built with a temporary floor, which was the reason for the wave. Otherwise the launching had gone off perfectly, as expected. Indeed, the engineers had been so confident of success that Emily Roebling and Mrs. William Kingsley had gone along with their husbands and several others on top of the caisson as it was sent hurtling down the ways.
At a large luncheon served in the Webb & Bell offices afterward everybody had been in high spirits. “We are now on foreign soil!” proclaimed John W. Hunter of Brooklyn, one of the stockholders. Everyone cheered. Then Henry Slocum got up and said he and Kinsella had agreed that Kinse
lla would do the speaking, while he did the thinking. But Kinsella interrupted immediately. Slocum was to do the drinking not the thinking, the editor said, and the laughter was very great according to later accounts.
After that Kinsella reminisced about the days when the bridge was no more than “the shadow in the brain of one man,” as he put it. “When William C. Kingsley [loud applause] was the founder, he put up more of fortune and reputation than any man I ever knew to do in an enterprise at the time so shadowy.” Then Slocum was on his feet again to propose a toast to Kingsley “as the man to whom we are more indebted than to all others.” There was a standing ovation for Kingsley, who said only that he had never made a speech in his life and asked instead that everyone drink to the health of Colonel Roebling. According to one version of the scene, Roebling was “subsequently introduced and loudly cheered, but not threats nor blandishments could coerce a speech out of him.”
The launching of the caisson and the celebrative luncheon afterward took place on May 8, 1871. There was still a great deal to be done, however, before the caisson would be ready for use. By the time it was completely fitted out, towed to position, and sufficiently loaded down so that the men could begin work inside, seven more months would have passed, the year would be nearly over, and by then if anyone were to use the word “shadowy” to describe the early business of building the bridge, it would be for quite different reasons. For by the time the New York caisson would start its descent, the Tweed Ring would have collapsed, something no one would have believed possible in May of 1871.
The year had begun splendidly for Tweed. On New Year’s Day Oakey Hall was again sworn in as mayor of New York and John T. Hoffman as governor. If everything went according to Tweed’s plan, 1872 would see Hoffman elected President of the United States, Hall governor, and Tweed a United States Senator, or at least so it seemed to a number of political observers.
David McCullough Library E-book Box Set Page 103