The Great Bridge

by David McCullough

  Kingsley had indeed purchased most of the stock and he had obviously handed it out where it would do the most good. He had every expectation of profiting from contracts with the Bridge Company, as the directors made no effort to deny, and it seemed pretty plain that he figured to recover what he had spent for political favors and for stock by the 15 per cent arrangement and quite possibly make a lot more on top of that. Had things continued as they were prior to the fall of 1871, there would have been no sudden unexplained changes in the 15 per cent arrangement and the bridge could have made him a very rich man. But the unexpected had happened. The Tweed Ring had crumbled like papier-mâché. Bargains with Tweed were no longer acceptable. Politically active building contractors were subjects of automatic suspicion. The whole bridge project was suddenly very suspect. Kingsley, just as suddenly, not to mention the whole Brooklyn Ring, was extremely vulnerable. His arrangement with the Bridge Company would not look good at all if it were to come to public attention. The management of bridge business might be put into other hands. The arrangement had to be changed, which it was, most hurriedly and clumsily.

  So the rug had been pulled out from under him before he had a chance to do much. But as a result no one was able to pin anything on him either. And besides, since the bridge was being built by a private company, there was, as no one could dispute, little he or any major stockholder could not do, perfectly legally.

  The importance of all this was not, however, the degree of Kingsley’s greed or guilt. What mattered in the long run was that largely by a quirk of fate—Tweed’s fall—the greatest municipal work of the age, the most inspired structure Americans had yet attempted, had been rescued from certain disgrace, and probable disaster, at the hands of the Tweed and Tammany rings. Moreover, the movement to make the bridge truly a public enterprise can be dated from this point. Two more years would go by before the old 1867 charter would be changed in Albany, but even so, the days when the Bridge Company could do entirely as it pleased were all over. No more could the Executive Committee and William Kingsley disregard public opinion or conduct their affairs with total immunity and no higher ethical standards to go by than those of a railroad.

  At the same time, those people who were actually building the bridge now had to face up to the idea that the work was no longer viewed as an altogether noble and heroic endeavor. Too many seeds of doubt had been sown and the fact that Tweed was out or that a man like Hewitt was in and testifying to the conduct of bridge business certainly did not put an end to the rumors. Papers such as the World remained openly hostile to the bridge and by no means satisfied that its management was henceforth above suspicion.

  One paper would list it as one of the “seven fraudulent wonders of the New World,” along with Tweed’s courthouse and the Northern Pacific Railroad. The bridge had been a subject of controversy since the beginning, of course, but always on technical grounds—i.e., was the engineering sound, would the finished structure stand or fall? Now there were other reasons to be skeptical and the bridge, as a result, became a subject of special fascination to a wholly different variety of skeptic, of whom there were a very large number.

  The same rich opportunities for dishonesty were still there, it was agreed, the same people had the power, and the void created by Tweed’s departure could well provide lesser scoundrels that much more room to maneuver in. A cloud of suspicion remained about the whole endeavor, in short, and come what may the bridge itself would be viewed by many as the very thing John Roebling had feared it might become when he contemplated its social and political setting ten years earlier: a grand and conspicuous aggravation to the general state of venality on both sides of the river. Despite anything said to the contrary, a good part of the public would remain convinced that every day the work continued some crooked somebody behind the scenes was getting rich on it.

  13

  The Mysterious Disorder

  Knowing from the reports of other similar works that compressed air was liable to affect some men unfavorably, every known precaution was taken to guard against this danger.

  —WILLIAM C. KINGSLEY

  BY THE FIRST of June, 1872, when the Chief Engineer and the General Superintendent issued their annual reports, the Brooklyn tower stood one hundred feet above the East River at high tide, while on the opposite shore the lower edge of the New York caisson rested seventy-eight feet six inches below the same tidal mark. The General Superintendent in his report stated that 14,500 cubic yards of masonry had been laid on the Brooklyn tower in the year past and 13,075 cubic yards on the New York tower. The Chief Engineer, however, wrote as follows:

  To such of the general public as might imagine that no work had been done on the New York tower, because they see no evidence of it above water, I should simply remark that the amount of the masonry and concrete laid on that foundation during the past winter, under water, is equal in quantity to the entire masonry of the Brooklyn tower visible today above the water line.

  It was an impressive way to picture what had been accomplished, if not quite accurate, according to Kingsley’s figures. To be informed that something of comparable magnitude to the Brooklyn tower had been built unseen below the river was for most people to have all the abstract explanations of counteracting pressures and penciled diagrams of timber caissons replaced in an instant with a single vivid image that anyone could appreciate.

  The massive, freestanding masonry tower rising at the edge of Brooklyn was still the only part of the bridge conspicuously on display. Through the whole of that spring, as charges of fraud and jobbery filled the papers and Brooklyn gossiped of bridge scandals, work on the tower had proceeded exactly according to schedule and the immense granite shaft was looked upon popularly as an irrefutable affirmation of all that had been promised and anticipated over the past several years. One look at something like this was enough to restore a person’s faith in what man could do and to make crooked bookkeeping and the like seem both terribly petty and no more than a temporary nuisance.

  In plan the tower was an irregular rectangle, its outside surfaces being broken up by heavy buttresses. It stood lengthwise against the shore, 140 feet long, 59 feet wide. So at a height of one hundred feet, it was still broader than it was high, still only a little more than a third as high as it would eventually go, and only nineteen feet short of the height of the roadway. But already it was considerably higher than anything else around it.

  Moreover, the tower kept gaining all the time, as though it were coming up out of the river, growing organically, instead of being slowly, methodically added to stone by stone. The change was never enough to notice from one day to another. Like the movement of an hour hand its progress was best seen at intervals. A Brooklyn dock worker on Furman Street might one morning notice that the stonework had gotten up above every ship mast since the last time he looked that way or a homebound commuter at the rail of a ferry pulling away from New York might realize one evening for the first time that this great blunt shaft with its feet in the water now topped the rise of the Brooklyn skyline.

  The intended purpose of the structure would have been rather hard to figure at this stage if one did not already know. In the very early morning, when the ferries still had their running lights on and before anyone was at work on the tower, it might have been taken for an ancient harbor defense, a gray solitary battlement standing guard over the swarm of ships to either side of it. And when the sun began coming up and lit the top of the tower, the derricks bristling there looked for all the world like medieval war machines, the trajectory of which, from such a height, would surely be enough to hit New York. But in the full light of day, with the sun glaring on its clean buff-colored granite, the tower looked very new indeed, and more like the beginnings of a gigantic astronomical observatory perhaps, or the pedestal for some breath-taking triumphal monument.

  But everyone did know its real purpose, of course, and could do little but marvel at its growth and at the way it seemed to diminish the size of everything else nea
rby. The ferryhouse, the most imposing Fulton Street stores, the newest business blocks, did not look so grand any longer. At the end of day, when the sun was a red ball hanging low over New Jersey and the west face of the tower seemed to be glowing from within, the granite pink nearly, everything in back of the tower stood in shadow for a block and more.

  When the Eagle claimed there was nothing on earth, save the Pyramids, to rival “this Brooklyn tower of ours,” nobody thought that especially high-blown. And now Roebling had introduced a new vision to stir the public imagination. Now, one need only look at the Brooklyn tower and picture the same thing concealed below water directly across the river. As far as this tower reached above the river, the other one reached below, like a gigantic rock taproot. (Roebling undoubtedly wrote what he did a number of weeks before it was published, at the time when the Brooklyn tower was indeed at about seventy-eight feet.) For every stone the crowds on the ferry had seen hauled up the face of the Brooklyn tower, another had been added to the burden of the New York caisson. And those seemingly fearless figures working along the uppermost rim of the tower were no farther above the surface of the East River than the men in the caisson were below it.

  Work inside the caisson was to be finished in another month. So it was the end of the first great stage in the building of the bridge, a clear dividing place. From here on the problems to be overcome, the work to be done, would be of an entirely different nature. Roebling made quite a point of this in his report, expressing congratulations to the Board of Directors “on the success which has attended the last of the two great tower foundations.” At the start of the work, he said, the foundations had been the principal engineering problem. The work to come—the building of the towers, the cable spinning, building the superstructure—was all work that had been done before on other bridges, on a smaller scale, “but upon the tower foundations rests the stability of the entire work.” Then he remarked almost as an afterthought, “Considerable risk and some degree of uncertainty was necessarily involved in their construction.”

  All the extensive preparations for receiving the caisson had been completed by the end of the first week in September 1871. The tower was to fill a space formerly occupied by two ferry slips, between Piers 29 and 30. The riverbed had been dredged out to a depth of thirty-seven feet, or a little more than twice as deep as at the Brooklyn site. A hundred feet of Pier 29 had been torn away, and a huge pile dock had been built, itself a bridge more than a hundred yards long between the new foundation and the shore. At the end of the dock a square enclosure for the caisson had been built of six-inch pine planks—this to break the force of the tidal current, which was decidedly stronger on the New York side.

  Borings made from the end of Pier 29 indicated bedrock anywhere from seventy-seven to ninety-two feet down. How far the caisson would have to go or whether even it was essential that it go clear to bedrock were questions that had still to be decided. But in any case the strata appeared to be chiefly gravel and sand, with layers of quicksand from fifteen to twenty feet thick. It was very different terrain from that at Brooklyn.

  The machinery needed was all standing by on the dock: three huge boom derricks similar to those used in Brooklyn, the same clamshell dredging equipment as before, hoists, steam engines, and pile-driving gear. Workshops and offices had been built, a blacksmiths’ shed, sheds for cement, tools, general stores, a compressor house (the largest building) with its air-pumping machinery set up inside—thirteen Burleigh compressors ranged in a single row, each with its own steam boiler, as compared to the six compressors used for the Brooklyn caisson.

  On September 11 the colossal wooden box was towed up from the Atlantic Basin, where in the four months since it was launched seven additional courses of timber, all laid with cement between, had been built on top. Once the pile enclosure was completed on the river side and the caisson confined to its permanent position, a final ten courses of timber were added, bringing the total height of the structure to just over thirty-one feet.

  Particular care had been taken this time to guard against sea worms. The protection was needed only during the time the caisson was afloat and before it was entirely submerged below the riverbed, where the sea worm, the teredo, never penetrates. But this microscopic animal, less than a sixteenth of an inch in diameter, can bore into any crevice water can get through, so the precautions had to be quite substantial. Every outside seam was caulked. The entire outside surface was heavily coated with a composition of coal tar, rosin, and a hydraulic cement, which, all by itself, was supposed to have enough body and grit to dull the teredo’s boring apparatus. Then this had been finished off with a sheet of tin covering all four sides and the top of the sixth timber course. All seams in the tin had been soldered airtight and layers of tar paper had been put in both above and below the entire sheet. Finally, the whole caisson had been sheathed in four-inch yellow pine saturated with creosote.

  “The great timber foundation was now complete!” Roebling wrote. “It contains 22 feet of solid timber above the roof of the air chamber, seven courses more than the Brooklyn caisson, and since the strength of such structures varies as the square of the depth, we may consider it to be nearly twice as strong as its Brooklyn brother.”

  In their general features the two caissons were almost identical. The sides of the New York caisson were again of yellow pine and tapered from nine feet thick on top to an iron cutting edge eight inches wide. The timbers used in the roof were again a foot square. Headroom inside the work chamber was nine and a half feet as before. The base dimensions were 102 by 172 feet, making the new caisson just four feet longer than the one in Brooklyn. The heavier roof had been built to carry what Roebling figured would be a significantly greater load, since this caisson would have to go much deeper and therefore carry far more stone. But there were several other differences as well.

  The light skin of iron boiler plate that lined the interior would not only provide fire protection, but make the caisson more airtight; and to improve visibility the whole inside had been given a heavy coat of whitewash. The water shafts this time, instead of being square, were round (they would be stronger this way Roebling had decided). In addition, some fifty iron pipes, four inches in diameter, had been installed throughout the work chamber as a way of removing sand.

  In the Brooklyn caisson there had been no means of communication between the men below and those working up on the surface. But here Colonel Paine had devised a simple, ingenious mechanical signaling system. One of the sand pipes was capped below and an inch tube was passed through the cap with index pointers attached above and below. Underneath each pointer was placed a small plan of the caisson, showing the position of every pipe and shaft. By rotating this tube immediate attention could be called to any of the points. In addition, a small rod was passed down through the pipe and its weight offset by a weight above that was attached to a cord that passed over a pulley. Small indexes were then fixed above and below. These moved up or down on vertical boards on which were printed such messages as “stop,” “start,” “bucket is caught,” and so forth.

  The arrangement of air locks was also quite different. This time there were two double locks, each large enough to accommodate thirty men, which meant that a full shift of 120 could enter or leave at one locking. And instead of being mounted on top of the caisson, as had been done in Brooklyn, the locks were built into the roof of the work chamber, so they actually projected down into the chamber about four feet. Each set of locks was connected to the top of the caisson by a spiral stairway enclosed in an iron shaft.

  The arrangement was essentially the same as Eads had used in St. Louis and it was over this particular feature that Eads and Roebling were to have their bitter falling out. The advantages to be gained were these, supposedly: the men could now step directly from the air lock into the work chamber, and at the end of the day they would not have to make the climb to the top while still under pressure.

  On October 31 the last timber course was finished,
the first stone of the new tower laid. By December 12 enough stone was in place to hold the caisson on the river bottom at high tide. The compressed air was turned on and Roebling, Paine, Collingwood, and a complement of some thirty men went down inside. (Since the water was thirty-seven feet deep and the caisson with all its timber courses stood thirty-one feet high, this left the top of the caisson just six feet below water at high tide and about two feet below at low tide.)

  Tearing out the temporary floor took another two weeks. When the digging began, the work proved nowhere near so difficult as it had been in Brooklyn, but much more disagreeable, for the caisson was standing in the middle of what for years had been New York’s principal dumping ground. Moreover, a street sewer was still emptying into the river close by.