John Roebling, the creative genius behind the Brooklyn Bridge project, had first envisioned it in 1852 after having witnessed the horrible delays caused by the East River choked with ice. However, because of suspicions among the public of whether a bridge that would have to be wide enough to allow boats to pass under it and strong enough to sustain the terrible winds and powerful currents of the river was possible, the project seemed unrealistic. The winter of 1866/1867, which was one of the worst ever recorded in New York, forced the people of Brooklyn to demand a bridge. As a result, on April 16, 1867, the New York legislature passed a bill which would “incorporate the New York Bridge Company, for the purpose of constructing and maintaining a bridge over the East River, between the cities of New York and Brooklyn.” (1, pg. 16) By June of 1869, John Roebling had completed the design for the bridge and work could finally begin. However, due to an unfortunate on-site accident, Roebling died shortly thereafter. All responsibility for the bridge was assumed by his son, Washington Roebling, who was named the new chief engineer. Time Management – Include time estimates for each stage of wbs
Construction on the bridge began in fall of 1869 and was completed May 1883, taking the bridge about fourteen years to build. Despite having as talented a chief engineer as Washington Roebling who provided very detailed plans for workers to follow, “the bridge had taken two and one half times as long as the five years John Roebling had predicted”. (1, pg. 104) This is in part due to some of the unforeseen problems with caissons, the underwater foundation Washington Roebling had decided to build the bridge upon, which at the time had been “used for small bridges in Europe, but the ones for the Brooklyn Bridge had to be much bigger.” (3, pg. 16) On the other hand, some unexpected caisson problems were dealt with successfully, thereby, avoiding additional delays. Construction on the first of the two caissons to be built, launched, sunk and filled with concrete started with the Brooklyn side of the river in January 1870 and ended in March 1871, taking a little over a year to complete. The caisson had been delivered by the contractor on time and launched into the river without any problems. However, digging down through the river with hand tools, as there was no electrical power, proved to be a formidable task, where “the rate of descent had been less than six inches a week” which “would take nearly two years to sink just the one caisson.” (2, pg. 196) With an army background, Roebling knew the answer was blasting which would save time and effort. With such great ideas as blasting being implemented to help speed things along, there were also crises that if they had been handled with as much expertise would not have resulted in the time lost and increased costs experienced. Towards the completion of the Brooklyn caisson, a fire caused by the carelessness of a worker put the project behind “more than two months and cost $15,000.” (1, pg. 48) Since compressed air within the caisson made the fire worse, Roebling ordered water to be continuously hosed in areas affected by the fire until he was certain the fire had been put out through drilling holes into the wood. When the fire was found to still be burning couple of hours later, decision was finally made to flood out the caisson to ensure the fire was out. Roebling also decided to fill the bored holes with concrete to reinforce the wood. However, the job had to be undone once it was discovered that the wood beneath the concrete was covered with charcoal. Any decay in the wood supporting the towers would be unsafe. As a result, he had all concrete taken out and the charcoal scraped away, with much of the wood replaced. Had the decision to flood the caisson been taken earlier, the outcome would have been much different. Intervention
Although a lot had been learned through the sinking of the first...
References: (1) The Brooklyn Bridge by Judith St. George
(2) The Great Bridge by David McCullough
(3) The Brooklyn Bridge by Elizabeth Mann
Please join StudyMode to read the full document