Brooklyn Bridge, ca. 1872-1887
Construction of the Brooklyn Bridge began in 1869. 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, 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. Roebling’s debilitating condition left him unable to physically supervise the construction firsthand.
Roebling conducted the entire construction from his apartment with a view of the work, designing and redesigning caissons and other equipment. He was aided by his wife Emily Warren Roebling who 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 for the Manhattan tower 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.
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.
The construction of the Brooklyn Bridge is detailed in the 1972 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.
The bridge—originally referred to as the New York and Brooklyn Bridge and as the East River 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 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.
Source: WikipediaClick to read the previous Throwback Thursday article.