The Building of Manhattan Read online

  THE WONDER OF THE IMAGINATION

  Technology can tell you how to build, but to have a vision of what you want to build—something larger and more complex than anyone has ever done before — and then to actually build it, requires a unique person.

  For thousands of years the world has looked at the pyramids of Egypt with awe. Their size still astonishes us. We wonder what manner of man conceived of such colossal undertakings.

  The builder of the first pyramid, the “step” pyramid, was a man of great daring, imagination, and ingenuity. We know his name, Imhotep, and he was worshiped by the Egyptians as a demigod.

  The master builders of the world, in all the different cultures and in all the different historical eras of human endeavor, have built to the limits of their knowledge and the capabilities of their time—and then went beyond those limits.

  Manhattan has been built by such men of daring, who upon seeing a challenge took it, and by so doing transformed the city. Two such builders were John Roebling, and after his death, his son, Washington Roebling.

  The proposal of John Roebling in 1867 to build the world’s largest suspension bridge, the Brooklyn Bridge, across the East River to connect Manhattan with Brooklyn was such a challenge. It was the enormous size of his proposed bridge that excited one’s imagination and raised some doubts that it could ever be built.

  John Roebling had no such doubts. He had already built suspension bridges, but none to compare with the one he now proposed.

  It would be more than a mile long.

  Two massive stone towers would have to be built in the turbulent East River. Above water they would be taller than any building yet built in Manhattan.

  To reach solid footing beneath the riverbed, men would have to dig from inside an enormous watertight box, called a “caisson,” which was about a third the size of a football field and would sink deeper into the river bottom as the men dug. The digging would present many perilous problems. Eventually the depth from high-water mark to foundation bottom on the Manhattan side would be 78 feet, 6 inches.

  One massive stone “anchorage” would have to be built on the Manhattan side and one on the Brooklyn side, weighing 60,000 tons apiece and each as tall as an eight-story building.

  Four steel-wire cables, each more than 15 inches thick, would be embedded in the Manhattan anchorage, supported across the tops of the two towers, and embedded in the anchorage on the Brooklyn side. Each cable would weigh over 1.7 million pounds and be made of 3,515 miles of twisted strands of wire. From these cables, others would hang down vertically, some diagonally, to support the 85-foot-wide bridge span that would arch at midpoint 130 feet above the East River— high enough for the tallest sailing ship to pass under.

  The roadway would have two levels: one for vehicular traffic, and above that an elevated promenade, for pedestrians. Roebling designed the openings through the two towers as soaring Gothic arches more than 100 feet high.

  The two arched towers of the Brooklyn Bridge are shown at nearly full height. The steam-powered boom derricks, held in place by guy wires, raise the great granite blocks—some eight tons apiece—to the top of the anchorage, shown here being built. On one occasion, as a granite block was being raised, a guy wire gave way. Two derricks fell from the tower, two men were killed, and several workers were injured.

  Iron anchor bars, set into the masonry and fastened to iron anchor plates embedded in the base of the anchorage, tie down the cables that will support the bridge deck. Workmen in the foreground are demolishing old buildings to make way for the approach to the bridge.

  Harper’s Weekly: drawn by W. P. Snyder

  THE SKILL OF THE ENGINEER

  John Roebling never saw any of his bridge built. His foot was accidentally crushed while he was surveying the waterfront where it was to be built, and the resulting infection killed him.

  John Roebling had the vision of the Brooklyn Bridge; his son, Washington Roebling, had the engineering training to build it.

  There was now a Society of Civil Engineers, founded in New York City in 1852. Its members specialized in constructing buildings and bridges, and studied the scientific use of materials employed in their profession. Young Roebling had graduated from the first school in the nation to provide engineering training, Rensselaer Polytechnic Institute in Troy, New York. As a Union officer during the Civil War he had built bridges under very difficult circumstances. He had been to Europe to study the innovations in engineering and metallurgy being used there, especially how Europeans built constructions underwater.

  The concept of the bridge had been carefully planned, but young Roebling would have to invent solutions to problems of construction that had never been tried before. One problem for which there seemed to be no solution was the “bends.” Its crippling effects afflicted some men, but not others. It was caused by too rapid decompression as the workmen went from the compressed air of an underwater caisson back into the natural atmosphere of everyday life.

  The problem: to devise a way for men to work underwater while excavating a rectangular area — 172 feet by 102 feet, about one-third the size of a football field — down through the mud and debris of the riverbed to a solid base upon which each bridge tower would then rest and be built upon a perfectly level foundation.

  The solution: build an upside-down wooden and iron box, open on the bottom, rest it on the riverbed, and keep the water from flooding in by increasing the air pressure within the work space.

  As the granite blocks of the bridge tower are placed onto the box, or caisson, the increasing weight will keep pressing the caisson into the river bottom. When the men have dug down so that the caisson has reached a solid bottom — 44 feet, 6 inches below high tide on the Brooklyn side; 78 feet. 6 inches on the Manhattan side—cement will be poured through the SUPPLY SHAFTS to fill the entire work area, and the bridge tower will be one solid mass resting on a solid base. Steam-powered boom derricks are on top of the granite blocks.

  The AIR LOCK was the means by which men could enter or leave the work chamber, which was always under the pressure of compressed air to keep the river from flooding in. Men entered through a hatchway that was then closed. Then they waited as a valve was opened and the pressure inside the air lock became the same as the pressure below. Finally they climbed through another manhole and down a ladder to the work area. To leave, the process was reversed.

  Clam-shell buckets, operated from above, dropped down the WATER SHAFTS to lift out the dirt and rock as it was dug from the riverbed. The water level in the shaft was regulated to an equilibrium with the air pressure in the working chamber to keep the water from dropping down from the shaft and flooding the work chamber.

  Roebling himself became an invalid as a victim of the bends. But he continued to direct all work from his home through his wife Edith and by his crew of assistant engineers.

  No one knows with certainty, but probably twenty men or more died during the construction of the bridge. The life of the unskilled laborer was a hard one. His pay for a day’s work digging underwater in the compressed air of the caissons was at first two dollars; in later years it was slightly higher.

  It took 14 years (1869-1883) to build the Brooklyn Bridge. When built, it was considered one of the wonders of the world — a construction concept and feat of overwhelming scale, beautifying the skyline of Manhattan. It is one of the favorite sights in all of New York, and listed as a National Historic Landmark. It is also one of the last of its kind: a construction of massive stone. The next bridges and buildings would make use of steel — a new material of great strength and much promise.

  Headroom for the workmen in the digging area was 9.5 feet. The roof above them was made up of five layers of one-foot-square pine timbers, bolted together. All the seams were sealed with thick caulking. A sheet of tin covered the top and sides and was then covered with wood. On top of all this, 10 more feet of timbers were added. The AIR LOCKS. SUPPLY SHAFTS, and WATER SHAFT all passed through this 15 feet of solid timber and into chambers built into the granite. The work area, always damp, was lit by calcium lamps and candles.

  THE IRON SKELETON

  Structural iron and steel gave strength without mass. They were versatile in form and use—they could soar upward as well as horizontally, be airy in feeling, curved or straight.

  But the transition from masonry-wall buildings to true iron-skeleton construction was a gradual process. Most office buildings built during the transition period used combinations of masonry, ornamental iron fronts, metal beams, and pillars of cast- and wrought-iron.

  Many office buildings of the late 1800’s still had masonry walls in addition to inner metal supports, for the skeleton frames of these earliest forerunners of today’s skyscrapers could not have stood without the support they received from their masonry walls. Both masonry walls and metal supports were built upward simultaneously as parts of the whole, and the metal parts were sometimes not joined to other metal construction.

  The metal skeleton would take over more and more of the load-bearing in the gradual evolvement of the tall office building. Eventually it would become, in the words of the 1931 committee examining the method of construction used in Jenney’s Home Insurance Building of 1884, “A type of construction in which a metal frame or cage comprised of girders, beams and columns supports all internal and external loads and carries all stresses directly to the foundations.”

  The style of the new tall buildings was still that of elaborate ornamentation under a wide assortment of historical influences. The elevator had opened up the top floors for ever-higher buildings. Rising land costs made tall buildings practical for the crowded city, and architects were quick to use this new architectural form: the metal-frame iron skeleton. Its horizontal metal beams transferred the weigh
t of the floors to the vertical columns, which, in turn, carried the load down to the foundation. The beams also tied all the uprights together and prevented them from moving sideways.

  In Chicago, in 1879, architect William Le Baron Jenney designed a building using cast-iron posts embedded inside the masonry of a conventional masonry building. These posts reduced the need for wide supports between the windows and carried part of the weight of the building. Five years later he designed the 10-story Home Insurance Building, with the first two floors of massive granite masonry. On top of this he built a brick and metal frame structure. which supported all the floor loads and the walls. This building was razed in 1931 and carefully examined during demolition in order to determine its method of construction. It is considered by many to be the first high building to use skeleton construction as a basic design principle.

  “AN IRON BRIDGE TRUSS STOOD ON END”

  In 1888 New York architect Bradford Lee Gilbert designed the Tower Building at 50 Broadway in lower Manhattan. It was 108 feet deep, but had a total available width of only 21 feet. 6 inches. The city’s building code stipulated that walls supporting a building’s superstructure be of such a thickness that. at street level. all but a little more than 10 feet of the width of Gilbert’s building would be solid walls. Gilbert pondered this problem for six months: how to make use of the 21.5-foot width on which his building would have to stand? He later slated in an interview in the New York Times that the idea came to him in a flash. “An iron bridge truss stood on end was the solution of the problem.” The building code did not limit the height of the foundation of a building, and Gilbert planned to carry his foundation columns—his iron bridge trusses—all the way up his building. 13 stories high. In a windstorm during construction people gathered to see if it would topple over. To calm the fears of the owner of the building. Gilbert himself proposed to occupy the top two floors of the structure. Now torn down, the building had a bronze plaque stating: “the earliest example of skeleton construction in which the entire weight of the walls and floors is borne and transmitted to the foundation by a framework of metallic posts and beams. date 1888-9.”

  Since ancient times. IRON has been made into tools and weapons by heating and hammering iron ore. When heated to a high temperature, iron becomes molten and, depending on the other components in the mix and the way it is treated. it can be fashioned into cast iron, wrought iron, or steel.

  Both wrought iron and cast iron were being used extensively in the construction of large bridges and buildings by the mid-1800’s.

  WROUGHT IRON has great strength in tension— resistance to forces that would pull it apart—which makes it structurally practical for use in horizontal beams. It is softer than cast iron.

  CAST IRON is hard but brittle, and has great strength under compression, making it superior to wrought iron for load-bearing uses, such as vertical supporting beams or pillars.

  In 1856. Henry Bessemer, in England, devised a cheap method of fabricating STEEL from pig iron. Steel, due to its greater strength, toughness, and resistance to wear, then began to supplant both cast iron and wrought iron, although both metals are still used in addition to steel for specific purposes today.

  Steel is made with many different characteristics. for specialized purposes, by the addition of specific ingredients to iron.

  Although nonflammable, all these metals are subject to collapse and potentially dangerous changes from extreme heat, such as fire. Thus they are coated with a fire-retardant protective surface after being put in place on a building project, such as a skyscraper.

  1850 TO 1900

  New York City was experiencing not only a building boom, but a population explosion as well. In just 35 years, from 1855 to 1890, nearly seven million immigrants arrived in the city from Europe. Since many stayed in New York to live and work, the strain placed upon the city’s services was enormous.

  Many lived in the most squalid conditions, yet visitors to the city were awed by the splendor of its buildings and the tempo of its life. The “French flat,” or apartment, appeared in the city; there were thousands of tenements. Central Park was man-made, created from undeveloped land.

  By the end of the century, upper Fifth Avenue from the Fifties to the Nineties would be inhabited by enormously rich people who built their palatial homes on land which had cost them from one hundred to two hundred dollars per square foot. The farms and shanty towns that had been there had long ago been pushed elsewhere. It was reported at the time that ingenious speculators would buy small lots in this fashionable area. Since there were no restrictions on the use to which these lots could be put, a speculator would announce plans to build an objectionable structure, whereupon his irate millionaire neighbor would buy him out at a nice profit. One promoter with a twenty-five-foot lot was described as planning a fifteen-story structure, probably an apartment-house, since it was felt that an office-building in that locality would never find any tenants. An appeal was made to strictly regulate the height and character of buildings on specific streets.

  Transportation was still a major problem. Elevated railroad lines with their steam locomotives had opened up both sides of upper Manhattan to development. But until the late 1800’s most transport was still provided by horse-drawn vehicles. And the city kept right on growing. In 1870 there were 942,292 people living on Manhattan Island and by 1880 the population total had passed the million mark, to 1,164,673. By 1890 it had reached a million and a half.

  As late as 1892 the tallest structure in the city was still Trinity Church with its 25-story-tall spire overlooking Wall Street, but ambitious men were now putting up office buildings with usable floor space at ever-increasing heights.

  An explosion of scientific ideas and practical inventions in America and Europe was revolutionizing the way people lived, and where and how they worked. The first commercial oil well was drilled. A railroad now crossed the entire continent. There were fountain pens, typewriters, adding machines, dynamite, and steel alloys, as well as aspirin, an antitoxin for diphtheria, and a vaccine against rabies. There were gasoline engines and gas and steam turbines. Electricity seemed miraculous. The telephone and telegraph made instant communication possible anywhere in the city.

  The value of city land rose dramatically. It was not only possible to build taller and bigger buildings with the new machines and processes that scientists and inventors had provided, it was now profitable to do so.

  New Yorkers were accustomed to living in a constantly changing city, the greatest in the nation. Their city had always grown horizontally, sideways to the Hudson and East rivers, and northward to the Harlem River and Spuyten Duyvil. It was now growing vertically, and beginning to give to the world a new vision of a great city — Manhattan, city of skyscrapers.

  THE FLATIRON BUILDING: 1901

  The Flatiron Building, Manhattan’s oldest skyscraper landmark, was originally named the Fuller Building for the construction company that built it and owned it. When erected, 1901-1903, it was the world’s tallest habitable building, at 300 feet.

  It is famous for its unique shape, a triangle formed by the intersection of Broadway and Fifth Avenue at 23rd Street. This piece of land was known as the “flatiron block” well before this building was even planned. The land price in 1901 was “not far from $2 million,” and the cost of the new building was another two million dollars.

  The new century had just begun. The average life expectancy in the United States for whites was about 47 years: for blacks, only 33 years. There were fewer than 10,000 autos in the whole country. Oklahoma, Arizona, and New Mexico were still territories, not yet states. The Wright brothers would make their first successful flight in an airplane on December 17, 1903; it would last 12 seconds.