Dan Simmons - Black Hills

Big Bill had had his own cure. However terrible the symptoms, he would drag himself down the stairs, into the air lock, and then plunge back into the darkness and pressure and smoke and sledgehammer crashes and plank-over-river-bottom-mud chaos of the caisson again. It always relieved his symptoms within minutes. Usually, he said, he’d work for an extra unpaid hour or two swinging sledges or priming charges while the caisson disease agony relented and then disappeared.

About twenty feet into the mud of the Brooklyn side of the East River, Big Bill told him, the caisson started encountering boulders too big to be broken up with sledgehammers and spikes and pry bars and sweat. Colonel Roebling conferred with Big Bill and two other new workers who, Bill thought, were also pretending to be experienced powdermen. Because the work of breaking up the boulders around the reinforced metal edge of the caisson—what they called the shoe—had moved from the almost impossible to the absolutely impossible no matter how hard the men labored down there in the heavy atmosphere in that box with the more than 27,000 tons of caisson roof and weights atop it, with tens of thousands of tons of weight of river and pressure above that, the workers were all for blasting.

Roebling had a few reservations. He explained to the three “powdermen” and the crew chiefs that in such a dense atmosphere inside the caisson, even a moderate explosion might blow out the eardrums of every worker in every room of the sunken box. Also, he explained, the compressed air in the caisson, already so filled with noxious gases as well as smoke and steam from the calcium limelights blazing at the end of their long iron rods, each torch throwing bizarre shadows and glare from its blue-white luminous jets, might become totally unbreathable when the smoke from an explosion was added to the mix. And the vibration from the blast, explained Colonel Roebling, might damage the doors and valves of the air lock—eliminating their only escape from the pressurized compartments on the bottom of the river.

Big Bill used to describe to Paha Sapa how the powdermen would look at one another so soberly after these explanations. But Roebling had an even greater worry.

The way rubble and sand were removed from the working area in the caissons was via water shafts—two huge columns of water that were being held in suspension above the spaces where the men worked merely by the great pressure of the air inside the caisson. The bottom of each water shaft pipe was open and only two feet above the pool of water they kept beneath it; handy for shoveling debris into and easy to send down a bucket through the standing column of water, but what—asked the Chief Engineer—would happen if an explosion inside the caisson to break up the boulders (and it had to be inside the caisson, of course) depressed that pool and allowed the air to escape up the shafts?

Big Bill said that he and the other work chiefs and powdermen had stared blankly.

Bill Slovak imitated Colonel Roebling’s voice, distorted by the terrible air pressure there in the corner of the caisson where they had the discussion, and the effect was strange, with Big Bill’s vocabulary suddenly enlarged, his voice distorted, and his accent lessened:

— It would be a total blowout, gentlemen. All the water suspended in that tall shaft above us, more than thirty-five feet today, perhaps all the water in both shafts, would erupt like a twin Vesuvius, and the compressed air that keeps us breathing and keeps the East River out would follow after it. I think that the eruption, seen from the outside, would rise at least five hundred feet. Parts of those workers nearest the water shafts would almost certainly be part of the extruded debris fountain. Then the full weight of the caisson, held up now only by the tremendous air pressure here, would come crashing down, smashing and flattening all the blocks and braces and frames and the outer edges of the shoe itself. All of these interior bulkheads…

Big Bill said that at this point the cluster of work chiefs and workmen, including the three “powdermen” so eager to light a fuse, had looked around them in the caisson, their wide, white eyes looking even wider and whiter in the blazing blue-white glare from the calcium limelights.

— … all of these interior bulkheads and supports would be crushed at once from the weight above. No one would have time to get to the air lock, or even to the narrow shafts serving the erupting geysers that were the water shafts until the blowout, and those fabrications of steel and iron—air shafts, air locks, water shafts, bracing, caisson shoe—would also be warped and crushed within seconds. And then the river would rush in, drowning any of us who might have survived the crushing force of the collapse.

The wide, white eyes, Big Bill told Paha Sapa (and sometimes five or six other listening miners) there in the black depths of the Holy Terror, then looked at one another a final time and turned back to Colonel Roebling.

— So, gentlemen, this new crop of boulders here is extruding outside the shoe beyond our reach and doesn’t seem to want to surrender to our ministrations by sledge and spike. The caisson’s own weight will continue to drop it deeper, and the shoe and framing will be inevitably damaged unless those boulders are removed. Shall we risk using explosives? We should decide today. Now.

To a man, they voted to try it.

But first, Big Bill Slovak explained, Roebling brought down his revolver left over from his service in the Civil War and tried firing it with increasingly heavier powder charges.

No one was deafened. The reports, said Big Bill, sounded strangely muffled in the hyperdense atmosphere of the caisson.

Then the colonel had Big Bill and the other two “experts” set off small charges of actual blasting powder in a remote corner of the caisson while others sheltered in the farthest rooms, slowly increasing the charge with each test.

The water shafts did not blow out, even as the amount of powder approached that necessary to break up the seemingly impervious boulders. The air locks were not damaged. The vibrations destroyed neither the inner bracings nor the workmen.

Big Bill said in the Holy Terror—

— The powder smoke, though, was a damned nuisance. We’d work for forty minutes or more in that thick, black cloud of smoke after each blast, not even being able to see the ends of our sledgehammers or pry bars, and I’d spit black phlegm the consistency of tar for weeks afterward.

But the results of a full charge were extraordinary. Boulders that would have held them up for days and damaged the settling caisson’s shoe were blown to bits in seconds, the bits then being pulverized and sent up the water shaft into the open world.

It was he himself, Big Bill told Paha Sapa, who suggested to Colonel Roebling that they adopt the miners’ technique of using a long steel drill hammered into the rock to create a hole for the blasting charge—the steam drill that they were all using at the Holy Terror in the Black Hills 1900 to 1903 hadn’t been invented yet in 1870 to ’71—and then the charge would be gently tamped in and set off. Big Bill, his hands twice the size of Paha Sapa’s, even at the decrepit old age of forty in the Holy Terror in 1902, had been in charge of the setting and tamping in the caissons.

In one eight-hour watch, said Big Bill, he and his two partners may have done twenty blasts. The other workers grew so used to the explosions that they—and the powdermen—would just calmly and slowly step into an adjacent chamber to escape all the flying rock and debris when an explosion was triggered.

Instead of descending six inches a week, as had been the case when they were breaking up boulders by hand, the Brooklyn caisson now dropped twelve to eighteen inches in six working days (everyone took Sundays off). Colonel Roebling raised Big Bill Slovak’s and the other powdermen’s pay twenty-five cents a week.