The Great Bridge

by David McCullough

  But the difficult work of dredging the site for the caisson was running far behind schedule. It would be another month before everything was ready there and nothing much could be done to speed things up. So apparently Roebling decided this would be an excellent time for him to go to St. Louis and see how Eads was progressing. The Bridge Company agreed and funds were provided for Horatio Allen to go along too.

  Eads had a regular routine for handling visitors and it appears that Roebling and Allen received the same treatment when they arrived in St. Louis in early April. Eads would go over the plans first, explaining things, then set out in a tender to the spot mid-river where a flotilla of barges and derricks hovered over his submerged caisson. The functions of the various workboats would be described, after which Eads would lead his guests down the narrow spiral stairway, through the air lock, and into the caisson proper.

  Roebling, as he would write later, had the highest admiration and respect for Eads and “his remarkable inventive talent.” Roebling also said later that Eads was extremely courteous to him during his two days in St. Louis and one man who was on hand at the time, a friend of Eads’s, said Eads took special pains to explain each and every detail to the younger engineer. So if there was any friction between them at this point in the story, there is no evidence of it.

  Roebling appears to have returned to Brooklyn confident he was proceeding along the best possible course, and although he must have heard a great deal about the caisson sickness in St. Louis, most of those he talked to, including Eads, were convinced that whether a man got hit or not was largely a matter of luck and to judge from things he said later Roebling had arrived at about the same conclusion. Certainly Eads then knew no more than Roebling did about how to prevent the trouble, or how to cure it, as must have been obvious to both of them. Men were still suffering, more of them were dying.

  Eads would keep plunging ahead with his work, sure that solutions could be improvised somehow should the problem grow still worse. In his place Roebling probably would have done the same. The great tragedy was that both of them were almost totally ignorant of what others had already learned about the effects of compressed air. They were both unaware, for example, that the surest, fastest remedy for caisson sickness was already known.

  Possibly things might have gone differently for each of them had they compared notes as time went on, or had they been in touch with the few others there were working on similar problems. But they were living in an age when communication among professional colleagues was, by later standards, frequently at the most superficial level. Engineering then, like nearly every other line of work, was intensely competitive. An organization such as the American Society of Civil Engineers was striving with some success to encourage an open exchange of professional information and there were several reputable journals publishing valuable technical material. Still there was as yet no strong tradition along these lines and in some quarters not even an inclination. The railroads, the biggest clients for engineering talent, as well as the training ground for a very large number of engineers, were not the sort of institutions to foster an open exchange of valuable ideas. Minding one’s own business was considered among the basic rules of business. There were trade secrets in other words, and the sharp rivalry men had to live with frequently gave rise to the worst kinds of professional jealousies and animosity. Roebling’s own father, for example, had once written to Charles Swan to warn him not to hire a certain man simply because he had once worked for Ellet. “I do not want any news carried between myself and Mr. Ellet,” John Roebling had said.

  There were exceptions, to be sure, but even then, often as not, it was because the party sharing his special knowledge stood to gain financially thereby. Carnegie had so agreeably granted Eads the benefit of Linville’s experience only when a large contract for the Keystone Bridge Company was involved. Eads’s own first instructions on caissons had been given by the French bridgebuilder Moreaux largely because Moreaux happened to be chief engineer for a leading French ironworks that, like the Keystone company, wanted to do the superstructure for Eads’s bridge.

  Perhaps, after Roebling returned to Brooklyn, he and Eads simply felt they had little more to say to each other, or little to gain by saying more than they already had. Or possibly for all their courtesies, things did indeed go sour at the start, simply on personal grounds. Eads, after all, was an exceedingly proud person who knew most all the answers always and was forever on his guard with anyone who might try to prove otherwise. He viewed his bridge, and none other, as the single most important engineering event of the century. Roebling almost certainly felt the same about the bridge he was about to build but, unlike his father, never once would he say so. Quite possibly Eads considered Roebling a threat and he was not about to stand in the shadow of any man. Maybe he simply saw Roebling as a nuisance.

  It is also understandable that a man who had achieved so much on his own, against all odds and despite the doubters, might be reluctant to go out of his way to help a young man who appeared to have been handed quite enough already, and who so far had done little to prove himself particularly worthy of all that. Furthermore, Eads at best was a difficult person. *

  But on top of everything else there was the prevailing belief of the time that a stiff spirit of independence was in itself a very good thing. And both Eads and Roebling were exactly the sort of men others would have pointed to as shining examples.

  So they would each go their own way, alone, set apart by half a continent and, in time, open hostility.

  On May 3, in the early afternoon, the Brooklyn caisson made its maiden voyage, which, of course, was also its final voyage—four miles down the East River to the site beside the Fulton Ferry slip. The chambers were again fully inflated, the air pumps were kept running, and the gigantic box was now riding with its deck a full nine feet above the water. (This inflation was essential, since in one part of the river there would be only a foot of space between the river bottom and the lower edge of the caisson.) Half a dozen tugboats took it in tow and proceeded out into the current at about quarter to two, “creating a great sensation among all whose good fortune led them to view one of the wonders of the nineteenth century,” which was so soon to be “hidden from the gaze of mortal eyes.”

  Roebling, Kingsley, Horatio Allen, Bell of Webb & Bell, and three or four others went along for the ride, standing forward on the long, flat deck. And any doubts Eads may have planted about the caisson staying afloat were quickly forgotten. In the words of one witness, it came down the river “as placidly as a swan upon the bosom of an inland lake.”

  They tied up a block above Fulton Street, and by the time the sun went down, several thousand people had given it their personal inspection. “Of course, everyone was anxious to be able to say in future years that they had been upon the monster,” wrote the Eagle. The monster, it seems, appeared even more formidable than anyone had expected and especially on toward dusk.

  The following morning, at the turn of the tide, the caisson was shifted into position inside the new basin, the whole operation taking little more than an hour. As the crowded ferries churned in and out of the slip next door, young men were seen climbing to the tops of the cabins for a better look.

  For the next several weeks additional courses of timber were built on the roof, each course at right angles to the other, with spaces left between the timbers, which were filled in with concrete to add weight and to help preserve the wood. Additional sections for the water shafts, air locks, and supply shafts were also installed as the roof grew in size. And on May 10, Roebling, Colonel Paine, and Francis Collingwood made the first inspection below. The temporary air compartment put in for the launching was removed, two doorways were cut through each of the interior walls, and any loose rock or mud under the edges was shoved out. A few men complained of trouble breathing the heavy air and apparently there was a sharp change in temperature inside the air lock every time the pressure changed, about which something would have to be done. T
he heat was up over 100 degrees. But otherwise everything was going as expected.

  In his report to the directors of the Bridge Company, signed June 12, Roebling wrote:

  For three weeks past a gang of forty men have been at work in the caisson for eight hours every day, under the charge of Mr. Young, principally in leveling off and removing boulders which happened to lie under the frames and the edges. A deposit of dock mud, from two to three feet deep, has made this work exceptionally unpleasant. The dredges, which are now beginning to work, will remove it in short time. The removal of large stones from under the shoe, some of them 100 cubic feet, is a matter requiring considerable skill and perseverance.

  During all this time the caisson was rising with every high tide, then resting on the bottom again at low tide, which, of course, meant that work within could be carried on only during the low-tide time of day, when the chambers were comparatively free from water.

  As more timber courses were added on top and the over-all height of the caisson was increased by a full ten feet, its center of gravity was raised considerably, causing a condition of “unstable equilibrium”—that is, the caisson would no longer rise uniformly with the rise of the tide. One end would come up ahead of the other and this would cause what was known as a blowout, a phenomenon of imposing appearance, as Roebling said, and the subject of much excited talk in Brooklyn.

  As the tide was rising, and the downward weight of the caisson was being overcome by the increased tension of the air inside, along with the buoyancy of the river outside, one end of the caisson would suddenly tip up six inches or more. For an instant the tension of the air inside exceeded the head of water outside, and there would be a huge rush of air from beneath the shoe, carrying with it a column of water weighing hundreds of tons to a height of maybe sixty feet. Fish would fall all over the top of the caisson and the men working there would scramble to gather them up.

  For the men inside the caisson such occurrences were quite terrifying at first, but of little serious consequence. There would be a terrific roaring noise and a sudden blast of air, both of which were decidedly unsettling, but after it had happened two or three times the men grew accustomed to it and the loss of a few hundred tons of air from a volume so large (163,000 cubic feet) was nothing to worry about especially.

  Seen from the shore or the ferry, however, the sudden appearance of a waterspout on the East River was a spectacle that would be talked about for years by all who saw it.

  It took three courses of stone and most of June before the vast wooden box was bobbing up and down no longer and was grounded on the bottom to stay. The first stone to be placed on top, the cornerstone as it were, was a block of blue limestone from the Kingston quarry, three feet by eight, weighing 5,800 pounds. There was no particular ceremony that went with it and so far as is known nothing was carved on it.

  A stoneyard, as it was called, had been established downriver, below the Atlantic Docks, near Red Hook, and four huge scows had been especially built to bring the stone up to the site. McNulty had been put in charge of laying the first courses and the work had gone much slower than normal since portable derricks had to be used to move massive blocks, weighing anywhere from two thousand to three thousand pounds apiece. But once the caisson was righted down, three permanent derricks were mounted directly on top of it. They had great wooden masts fifty feet high, like the masts of a ship, and booms that were capable of swinging to any point on the deck.

  By now, too, six big air compressors, built by the Burleigh Rock Drill Company, of Fitchburg, Massachusetts, were in operation inside a long shed nearby in the yard. Each had a twenty-horsepower steam engine driving two single-acting air cylinders of fourteen-inch stroke and fifteen-inch diameter. Each engine had its own boiler and they were all so connected that the stopping or breaking down of one boiler or engine would not affect the others. All piping and connections were in good order and working properly. (A ten-inch main took the compressed air underground some 150 feet to the caisson, where two six-inch rubber hoses carried the air down the supply shafts to the work chambers.) Thomas Douglas, a mason who had done the finest stonework in Prospect Park, had been put in charge of the labor outside the caisson, while the foreman inside was a strapping man named Charles Young.

  To date everything had gone exactly as planned. There had been no serious interruptions. Material had arrived on time. All necessary machinery had been purchased and installed. Proper offices had by now been established for the Bridge Company in the Union Building on Fulton Street, which was only a short walk from the Fulton Ferry. Everyone involved was to be congratulated, wrote General Superintendent William Kingsley in his own first official report.

  The great caisson could now begin its descent.

  9

  Down in the Caisson

  We have no precedent just like this bridge.

  —WASHINGTON ROEBLING

  IN ALL the thousands of years men had been building things, no one had ever attempted to sink into the earth so large a structure as the Brooklyn caisson and there were not very many places where the job would have been more difficult than the Brooklyn side of the East River.

  Roebling and his assistants thought they had learned quite a lot about the ground they had to penetrate while dredging the site, but as he commented with his usual dispassion, “The material now became sufficiently exposed to enable us to arrive at the conclusion that it was of a very formidable nature, and could only be removed by slow, tedious, and persistent efforts.” Compared to this everything before had been child’s play. Now that which had looked so reasonable on paper was turning out to be quite a different matter in practice. Indeed, so bad was the first month of excavation inside the caisson, so painfully slow and discouraging, that it began to look as though the whole idea for the foundations had been a terrible mistake, that they would have to give up and try again some other way or some other place.

  There was never any public awareness of such feelings, which was just as well. There was, for that matter, very little real awareness on the part of the public of what actually went on inside the caisson, the work being entirely concealed.

  The best over-all view of the site was still from the deck of the ferry. So every day thousands of people on their way to and from New York got a splendid, close-up look at the three towering boom derricks swinging blocks of limestone into place and at the squads of men swarming about the masonry work or through the adjacent yards, every last man appearing to know just what was expected of him. There were half a dozen different steam engines sending up columns of black smoke and everywhere a bewildering clutter of tackle, hand tools, nail kegs, and tar barrels, stacks of lumber and great heaps of coal, sand, and stone. How anything orderly or rational might emerge from such seeming chaos was something for ordinary men to ponder in dismay.

  Still, seen from above, the work did not appear all that different from other big construction projects. The activity around the gigantic new Post Office being built in New York, for example, was every bit as confusing and impressive to watch. All this was lit by the same light of day and the men appeared no different from other mortals, breathing the same good air. But down in the caisson, everyone had heard, things were different. That was the part of the work that had the most fascination and of course the fact that it was hidden away where no one could see it, except for a relative few, made the fascination that much greater.

  The newspapers sent reporters down soon enough. By July better than two hundred workers were going down every day and naturally they had their own stories to tell. So as a result a picture began to emerge, of a strange and terrifying nether world at Brooklyn’s doorstep, entered only by men of superhuman courage, or by fools, and as sometimes happens with ideas that grow in the imagination, it was not so very far from the truth.

  Probably the most vivid description was one given by E. F. Farrington, Roebling’s master mechanic, a plain, blunt, practical man ordinarily. There would be rumors later about who actually was do
ing Farrington’s writing for him, or at least dressing up his literary style, but there is no doubting the authenticity of the image.

  Inside the caisson everything wore an unreal, weird appearance. There was a confused sensation in the head, like “the rush of many waters.” The pulse was at first accelerated, then sometimes fell below the normal rate. The voice sounded faint unnatural, and it became a great effort to speak. What with the flaming lights, the deep shadows, the confusing noise of hammers, drills, and chains, the half-naked forms flitting about, with here and there a Sisyphus rolling his stone, one might, if of a poetic temperament, get a realizing sense of Dante’s inferno. One thing to me was noticeable—time passed quickly in the caisson.

  Even the air lock was an unnerving experience for most men the first time they went down. For some it was also an extremely painful experience. The little iron room was abundantly lighted by daylight through glass set in the ironwork overhead. But once the attendant had secured the hatch with a few turns of a windlass, the common sensation was that of being enclosed in an iron coffin. Then a brass valve was opened. “An unearthly and deafening screech, as from a steam whistle, is the immediate result,” wrote one man, “and we instinctively stop our ears with our fingers to defend them from the terrible sound. As the sound diminished we are sensible of an oppressive fullness about the head, not unaccompanied with pain, somewhat such as might be expected were our heads about to explode.” (For many the sensation did not pass and they were said to be “caught in the lock.”) Then the sound stopped altogether, the floor hatch fell open by itself, and the attendant pointed to an iron ladder leading into the caisson. The immediate wish of most men at this point, whether they showed it or not, was to get back out into the open air just as fast as humanly possible. But once the ladder had been negotiated and three or four minutes had passed, most men also found they felt reasonably steady.