Construction of the Brooklyn Bridge
2/6/2012
The year is 1866. The American Civil War ended only one year earlier and life in New York City was returning to its normal pace focusing on urban affairs (New York not only had brigades engaged in battle, but this was also the scene of the great draft riots in 1863). New Yorkers, especially Brooklynites, were more than a little frustrated about traveling across the East River during the winter months when ferries could not cross the icy waters. Through the vision of a German immigrant, John Roebling, the city embarked on a monumental project. That is, to build a suspension bridge that would span almost 1600 feet – the largest of that kind to be attempted. It would also be the first suspension bridge to use steel cables to support its massive structure.
The construction of the Brooklyn Bridge started in 1869. It took 14 years and 27 lives to complete.
The first objective was to securely anchor the bridges two towers on solid bedrock located under the layers of mud below the East River. To do this, huge wooden caissons, resembling giant boxes, were assembled on land and then towed to their position and sunk. A caisson is a retaining, watertight structure. Once put into place, water is pumped out of them so that workers can enter and perform their assigned job tasks in a dry environment; truly a dangerous setting even under the most stable of conditions. Compressed air had to be pumped into the caisson to prevent the surrounding waters from leaking in. The caisson’s floor was then ripped out so workers could dig out the river bed mud to reach the solid bedrock. Reading first-hand descriptions of the conditions inside the caissons, one could easily conjure up images from Dante’s Inferno. There was high pressure (to ensure the caisson would not leak), suffocating heat and a reduction of oxygen content as well as extremely high noise levels. As such, these conditions limited a worker’s time within the caisson to two hours (maximum).
As workers would ascend to the top of the caisson, they were threatened with a very serious condition that today is known as “the bends.” However, during construction of the Brooklyn Bridge, it was known as “Caissons Disease.” This condition, also known as decompression sickness (something all underwater divers are aware) arising from dissolved gases coming out of solution into bubbles inside the body on depressurization. Workers inside the caissons would experience this ailment as the bottom of the caisson was pressurized well over atmospheric conditions as one tower had a depth of 44 feet and the other; 78 feet. Because of the increased pressure associated with these depths (33 feet of water equals one atmosphere), rising to the top would cause a rapid (too rapid) dissolution of our breathing air gasses (mostly nitrogen, oxygen and carbon dioxide) from our blood, thus quickly forming bubbles and lodging at various locations inside our body. This is visually comparable to a carbonated drink that is manufactured at sea level and brought up to the maintains – as soon as the cap is opened, carbon dioxide bubbles are formed causing its contents to gush out (giving yourself an expected drenching). However, when this depressurization occurs in our blood stream, the effects can be quite severe. Results may vary from joint pain and rashes to paralysis and even death. Individual susceptibility can vary from day to day, and different individuals under the same conditions may be affected differently. As a matter of fact, John Roebling’s son, Washington, was a victim of this condition, leaving him paralyzed. He was left bed-ridden and was on his death bed at the time of the bridge’s inauguration.
Washington Roebling’s devastating experience was not the only one that his family suffered, for John Roebling, himself, was a fatal statistic. 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. This happened not long after he had placed his 32-year-old son, Washington Roebling, in charge of the project. After Washington’s ailment, his wife, Emily Warren Roebling, stepped in and provided the critical link between her husband and the engineers on site.
On many of our own projects, we are asked to provide work that requires innovation; work in which there is no book to guide us. The fact may be that during these times, we may be writing the book! While the construction of the Brooklyn Bridge may be considered one of the ultimate examples of a project that becomes a blueprint for others to follow, we can take a page out of this historic moment for a lessons learned. It is imperative that we understand the importance of examining our processes, thereby understand the potential hazards associated with our work and to develop the proper controls to protect ourselves and fellow-employees – before we start our field tasks. While there was no OSHA when the Brooklyn Bridge was constructed, we should keep in mind that the existence of OSHA and other organizations that are dedicated to the health and safety of workers, cannot ensure that workplace hazards are properly controlled. This was realized only recently, with the construction of the mega casino/hotel/resort, City Center, in Las Vegas, Nevada: a project that lasted five years (completed in December 2009), costing nine billion dollars and the lives of twelve workers. According to all available information, these tragedies (mostly falls and being struck by objects) were all preventable – even though this was a highly visible job with the State OSHA administration having a focus on the project.
While the principles of Integrated Safety Management and the International Organization of Standardization (ISO) 14001 policy emphasizes rigorous planning to identify work steps and their associated hazards, many times, we cannot recognize or foresee such events during planning stages and only realize potential hazardous situations while performing the actual processes. This is where we must be vocal and inform our fellow workers and project management so that corrective measures may be included into the work steps (prior to performing such tasks) and keep our work environment free from those things that can injure us and our fellow workers.
As a side note, caissons are covered in the OSHA regulations; not under the confined space standard (29 CFR 1910.146) but under the Construction standard, 29 CFR 1926, 802 and 803 (Sections titled “Caissons” and “Cofferdams”).
Obstacles are those frightful things you see when you take your eyes off your goal
Henry Ford