Brooklyn Bridge

The Brooklyn Bridge might not have been built had it not been for the assistance of Emily Warren Roebling, who provided the critical written link between her husband, Washington Roebling (the Chief Engineer), and engineers on-site. Most history books cite Washington Roebling’s father John Roebling and Washington Roebling as the bridge’s builders. Early into construction, however, John Roebling’s foot slipped into a group of pylons from the shake of an incoming ferry. This badly crushed his toes, causing those toes to be amputated, leaving him incapacitated; he later died of an infection related to this injury and leaving his son, Washington Roebling, in charge of the bridge. The actual construction started under the younger Roebling. Not long after taking charge of the bridge, Washington Roebling suffered a paralyzing injury as well, the result of decompression sickness. This condition plagued many of the underwater workers, in different capacities, as the condition was relatively unknown at the time and in fact was first called “caisson disease” by the project physician Dr. Andrew Smith. With both men out of commission, Emily Warren Roebling provided critical assistance in providing the communications between her husband and the engineers on-site. Under her husband’s guidance, Emily had 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 in the supervision of the bridge’s construction.

The opening ceremony was attended by several thousand people and many ships were present in the East Bay for the occasion. President Chester 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 Roebling’s home, after the ceremony. Washington Roebling was unable to attend the ceremony 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.

At the time it opened, it was the longest suspension bridge in the world – 50% longer than any previously built – and it has become a treasured landmark. For several years the towers were the tallest structures in the Western Hemisphere. Since the 1980s, it has been floodlit at night to highlight its architectural features. The towers are built of limestone, granite, and Rosendale cement. Their architectural style is neo-Gothic, with characteristic pointed arches above the passageways through the stone towers.

The bridge was designed by German-born John Augustus Roebling in Trenton, New Jersey. Roebling had earlier designed and constructed other suspension bridges, such as Roebling’s Delaware Aqueduct in Lackawaxen, Pennsylvania, the John A. Roebling Suspension Bridge in Cincinnati, Ohio, and the Waco Suspension Bridge in Waco, Texas, that served as the engineering prototypes for the final design.

During surveying for the East River Bridge project, Roebling’s foot was badly injured by a ferry, pinning it against a pylon; within a few weeks, he died of tetanus. His son, Washington, succeeded him, but in 1872 was stricken with caisson disease (decompression sickness, commonly known as “the bends”), due to working in compressed air in caissons. The occurrence of the disease in the caisson workers caused him to halt construction of the Manhattan side of the tower 30 feet short of bedrock when soil tests underneath the caisson found bedrock to be even deeper than expected. Today, the Manhattan tower rests only on sand. Washington’s wife, Emily Warren Roebling, became his aide, learning engineering and communicating his wishes to the on-site assistants. When the bridge opened, she was the first person to cross it. Washington Roebling rarely visited the site again.

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 $725 million project to replace the approaches and repaint the bridge is scheduled to begin in 2009.