The Brooklyn Bridge is a majestic span with its elegant gothic towers and roadway suspended above the East River. Today we take it for granted, but at the time it was built it was called “the eighth wonder of the world.” However, the bridge never would have been built without major contributions from a Greenpoint shipyard and an engineer from Kent Street.
Building these massive objects was a massive engineering feat. Nothing like these caissons had ever been built before. There was one for each bridge tower and they weighed an amazing three thousand tons each. In the history of human construction, nothing so large had ever been sunk into the earth. The caissons were 168 feet long and 103 feet wide, an area covering half a city block. These large boxes had 110, 000 cubic feet of timber and two hundred and fifty feet of iron with iron walls and a ceiling six feet thick.
Webb and Bell insisted on being paid $100,000 in advance for the complicated task of building them. To dig inside the caissons workers needed air—so the caissons were built with a revolutionary new technology: air locks made of one-half inch boiler plates, seven feet by six and a half inches in diameter. The massive caissons would be built in parts and then welded together at the foot of the bridge because of the enormous size of the caisson pieces.
There was one engineering task that was incomplete before bridge construction could begin. They needed to find a centerline for the bridge. In 1870 Roebling and Payne worked together to survey the site and draw out the centerline. Payne would continue to play a major role in inspecting the bridge because Roebling suffered a debilitating sickness during construction of the bridge. Payne became the chief inspector for the bridge. One of Payne’s major contributions was the discovery that a disreputable firm hired to create the span’s wire cable was using dangerous sub-standard cable. Payne also later designed the trolley system that allowed cable cars to travel safely across the bridge. Today Payne’s name is inscribed in a plaque at the center of the bridge for his huge contributions in building it.