Brooklyn Bridge
History
The Brooklyn Bridge is a hybrid cable-stayed/suspension bridge in New York City, spanning the East River between the boroughs of Manhattan and Brooklyn. Opened on May 24, 1883, the Brooklyn Bridge was the first fixed crossing across the East River. It was also the longest suspension bridge in the world at the time of its completion, with a main span of 1,595.5 feet (486.3 m) and a deck located 127 ft (38.7 m) above mean high water.
The bridge was initially designed by German immigrant John Augustus Roebling, who had previously designed and constructed shorter suspension bridges, such as Roebling's Delaware Aqueduct in Lackawaxen, Pennsylvania, and the John A. Roebling Suspension Bridge in Cincinnati, Ohio.
Design and construction
While conducting surveys for the bridge project, Roebling sustained a crush injury to his foot when a ferry pinned it against a piling. After amputation of his crushed toes, he developed a tetanus infection which eventually resulted in his death, leaving his son Washington Roebling in charge of the project.
Washington Roebling also suffered a paralyzing injury as a result of decompression sickness shortly after the construction of the Brooklyn Bridge began. This condition, first called "caisson disease" by the project physician Andrew Smith, afflicted many of the workers working within the caissons. After Roebling's debilitating condition left him unable to physically supervise the construction firsthand, his wife Emily Warren Roebling stepped in and provided the critical link between her husband and the engineers on site.
Structure
The Brooklyn Bridge is built from limestone, granite, and Rosendale cement. The construction process involved several novel features, including large, pneumatic caissons, which were fitted into the bedrock. The towers are built of limestone, granite, and Rosendale cement. The granite was quarried at the Beattie Quarry in Graniteville, Staten Island.
The bridge's two towers were built by floating two caissons, giant upside-down boxes made of southern yellow pine, in the span of the East River, and then beginning to build the stone towers on top of them until they sank to the bottom of the river. Compressed air was pumped into the caissons, and workers entered the space to dig the sediment, until the caissons sank to the bedrock. The whole weight of the bridge still sits upon a 15-foot thickness of southern yellow pine wood under the sediment.
Impact and legacy
The Brooklyn Bridge has had a significant impact on New York City's urban development. It has facilitated transportation between Brooklyn and Manhattan, contributing to the growth of residential areas in Brooklyn. The bridge has also become a symbol of New York City, and it is a National Historic Landmark.