Brooklyn Bridge - Construction

Construction

The Brooklyn 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, Waco Suspension Bridge in Waco, Texas, and the John A. Roebling Suspension Bridge in Cincinnati, Ohio.

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 left him incapacitated and soon resulted in his death, not long after he had placed his 32-year-old son Washington Roebling in charge of the project.

Washington Roebling also suffered a paralyzing injury as a result of decompression sickness shortly after the beginning of construction on January 3, 1870. 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 written link between her husband and the engineers on site. Under her husband's guidance, Emily studied higher mathematics, the calculations of catenary curves, the strengths of materials, bridge specifications, and the intricacies of cable construction. She spent the next 11 years assisting Washington Roebling helping to supervise the bridge's construction.

When iron probes underneath the caisson found the bedrock to be even deeper than expected, Roebling halted construction due to the increased risk of decompression sickness. He later deemed the aggregate overlying the bedrock 30 feet (9 m) below it to be firm enough to support the tower base, and construction continued. Harbor pilot Joseph Henderson was called upon as an expert seaman to determine the height of the water span of the Brooklyn Bridge.

The towers are built of limestone, granite, and Rosendale cement. The granite blocks were quarried and shaped on Vinalhaven Island, Maine, under a contract with the Bodwell Granite Company, and delivered from Maine to New York by schooner.

The Brooklyn Bridge was opened for use on May 24, 1883. The opening ceremony was attended by several thousand people and many ships were present in the East Bay for the occasion. President Chester A. Arthur and New York Mayor Franklin Edson crossed the bridge to celebratory cannon fire and were greeted by Brooklyn Mayor Seth Low when they reached the Brooklyn-side tower. Arthur shook hands with Washington Roebling at the latter's home, after the ceremony. Roebling was unable to attend the ceremony (and in fact rarely visited the site again), but held a celebratory banquet at his house on the day of the bridge opening. Further festivity included the performance of a band, gunfire from ships, and a fireworks display.

On that first day, a total of 1,800 vehicles and 150,300 people crossed what was then the only land passage between Manhattan and Brooklyn. Emily Warren Roebling was the first to cross the bridge. The bridge's main span over the East River is 1,595 feet 6 inches (486.3 m). The bridge cost $15.5 million to build and approximately 27 people died during its construction.

On May 30, 1883, six days after the opening, a rumor that the Bridge was going to collapse caused a stampede, which was responsible for at least twelve people being crushed and killed. On May 17, 1884, P. T. Barnum helped to squelch doubts about the bridge's stability—while publicizing his famous circus—when one of his most famous attractions, Jumbo, led a parade of 21 elephants over the Brooklyn Bridge.

At the time it opened, and for several years, it was the longest suspension bridge in the world—50% longer than any previously built—and it has become a treasured landmark. Since the 1980s, it has been floodlit at night to highlight its architectural features. The architectural style is neo-Gothic, with characteristic pointed arches above the passageways through the stone towers. The paint scheme of the bridge is "Brooklyn Bridge Tan" and "Silver", although it has been argued that the original paint was "Rawlins Red".

At the time the bridge was built, the aerodynamics of bridge building had not been worked out. Bridges were not tested in wind tunnels until the 1950s, well after the collapse of the original Tacoma Narrows Bridge (Galloping Gertie) in 1940. It is therefore fortunate that the open truss structure supporting the deck is by its nature less subject to aerodynamic problems. Roebling designed a bridge and truss system that was six times as strong as he thought it needed to be. Because of this, the Brooklyn Bridge is still standing when many of the bridges built around the same time have vanished into history and been replaced. This is also in spite of the substitution of inferior quality wire in the cabling supplied by the contractor J. Lloyd Haigh—by the time it was discovered, it was too late to replace the cabling that had already been constructed. Roebling determined that the poorer wire would leave the bridge four rather than six times as strong as necessary, so it was eventually allowed to stand, with the addition of 250 cables. Diagonal cables were installed from the towers to the deck, intended to stiffen the bridge. They turned out to be unnecessary, but were kept for their distinctive beauty.

After the collapse in 2007 of the I-35W highway bridge in the city of Minneapolis, increased public attention has been brought to bear on the condition of bridges across the US, and it has been reported that the Brooklyn Bridge approach ramps received a rating of "poor" at its last inspection. According to a NYC Department of Transportation spokesman, "The poor rating it received does not mean it is unsafe. Poor means there are some components that have to be rehabilitated." A $508 million project to replace the approaches began in 2010 and is scheduled to run until 2014. As part of this project, two approach ramps will be widened from one lane to two, and clearance over the Brooklyn Queens Expressway will be increased.

The construction of the Brooklyn Bridge is detailed in the 1978 book The Great Bridge by David McCullough and Brooklyn Bridge (1981), the first PBS documentary film ever made by Ken Burns. Burns drew heavily on McCullough's book for the film and used him as narrator. It is also described in Seven Wonders of the Industrial World, a BBC docudrama series with accompanying book.