The enduring power of architectural landmarks stems from the stories they recall, as well as the emotions they evoke in the viewer. From the Brooklyn Promenade in New York, the casual observer can see such icons as the Statue of Liberty, as well as the still-noted absence of the World Trade Center towers, whose monuments are even now starting to rise from the dust. These structures are clear examples of places with stories and with emotions, but they are not alone in this category on the Lower Manhattan skyline. They are joined by the equally impressive and perhaps even more unique Brooklyn Bridge.
Before the bridge became a design and then a reality, the East River was an obstacle inhibiting passage between the two separate, growing cities of Brooklyn and Manhattan. Then as now, residents were wont to live in Brooklyn and work in Manhattan, but the only way to cross between the two cities was by slow, crowded, and unsafe ferries. Ice in the winter could halt all passage, and high winds could send the boats aground. These circumstances made the so-called “Great Bridge” a much-needed project.
The problem lay in the river itself, and in the capacity of contemporary engineering to conquer it. Historian David McCullough writes in his book The Great Bridge that, “the East River...is no river at all technically speaking, but a tidal strait and, in that day, especially, one of the busiest stretches of navigable salt water anywhere on earth” (24). There was no hope of supporting the bridge in the center of the river; it required a single arc stretching between Brooklyn and Manhattan.
Enter the engineers. John Roebling had pioneered construction of suspension bridges in Pittsburgh, Niagara Falls, and Cincinnati; his son, Colonel Washington Roebling, worked with his father on these projects, serving as both confidant and co-engineer. These bridges separately formed the core of the Great Bridge in Brooklyn, an efficient design that allowed for the crossing of a near-impassable body of water.
The design principle of the suspension bridge worked better for the Brooklyn Bridge than any other design could have. Suspension bridges are capable of spanning up to 7,000 feet through the use of compression and tension. Two towers are embedded in the earth to support the majority of the deck's weight; cables are strung to hold tension as they are stretched taut between two anchorages. The cables are able to transfer the pressure (compression) of the deck to the towers and then directly into the earth. (For more on suspension bridges, check out http://static.howstuffworks.com/pdf/ups-suspension-bridge.pdf )
The bridge would cost the Roeblings dearly-- indeed, it turned out that John Roebling's legacy would be as the bridge's designer; an accident at the work site and its subsequent surgery went bad and killed him. Washington Roebling served as the bridge's chief engineer until its completion, though it impacted his health negatively too.
The Great Bridge also made use of the most recent technology in its construction. This was particularly true of the caissons that were to support the towers, which had to be sunk in the river and work be conducted inside to permanently embed them in the stone at the bottom of the river. Weight on top, compressed air inside, and excavation of the riverbed would all help to push these great structures to a stable position at the bedrock, where they would be filled with concrete.
This simple concept, however, became a more complicated reality when they had to adapt the workers to such starkly different levels of air pressure. This situation lead to the ailment that we now know as “the bends,” sharp pain in the joints that appeared among workers coming out of the caissons, and was first identified during the work on the Eads Bridge in St. Louis. In some cases, both in St. Louis and in Brooklyn, the disease would cause paralysis or even death. Among these statistics was Washington Roebling himself, who was paralyzed by an attack of “the bends” in 1872, and ultimately had to oversee the final construction of the bridge from his house near what is now the Brooklyn Promenade.
The bridge's tall granite towers and proud arches dominated views of Lower Manhattan when it opened in 1883. Though it no longer claims that distinction today, it still represents the stories of the men who designed it and the men who built it, as well as the use of modern science to overcome the adversity of nature to human progress. By linking two previously separate cities together, the Brooklyn Bridge represents the most practical of monuments, one that provides a spectacle for the eye, an experience for the tourist, and a functional transportation option for all who would pass over it.