Ishvar Sitaldin
Professor Weyn
ENGL 21007
February 27, 2023
One of the Fundamentals of Bridge Building
In this essay, I will be discussing the subject of Caisson’s, a device used in bridge building. I was first introduced to this subject when the professor gave us a handout about the Brooklyn Bridge during our English class. This handout was also something like an informational essay about the Brooklyn Bridge, in which we are told about the history of the Brooklyn Bridge and the people behind it. The handout was written by Elizabeth Mann and informed me of many things about the Brooklyn Bridge, one of them being caissons. In this essay, I will dive into the history of the caisson and look at the negative effects workers faced when working in this pressurized chamber. At the end of the essay, we will also look at other notable use cases of the caisson during its history.
First, we will start with the fundamentals of what a caisson is and how it works. To completely simplify it think of the caisson as a massive pressurized chamber that is used to be able to work on foundations of bridges, constructions of dams, or even for the repair of ships. Caissons are built in such a manner that the water can be pumped out from the bottom which leaves the chamber dry and allows people to work deep beneath the water level. Caissons are brought down through soft mud until a suitable foundation material is encountered. While bedrock is preferred, a stable, hard mud is sometimes used when bedrock is too deep (Wikipedia, Caisson, n.d.). The latter was the case when this method was used for the Brooklyn Bridge, on the New York side of the bridge the caisson kept sinking deeper below the river without reaching solid bedrock. After doing many tests the Chief Engineer at the time, Washington Roebling, decided that the surface was strong enough to support the bridge and halted the further lowering of the caisson. He was especially worried because many of his workers kept getting sick, and one of them even died during the installation of this caisson (Mann, 1996). But why were so many workers falling sick? What caused that to happen? Many started calling it caisson disease.
Caissons disease is more widely known as decompression sickness, it occurs when people leave high-pressure environments and return to normal or lower-pressure environments too quickly. This is what the workers of the Brooklyn Bridge experienced in the caissons. Decompression sickness is a medical condition that is caused by dissolved gases emerging from solution as bubbles inside the body tissues during decompression. This disease has many symptoms ranging from joint pain and rashes to paralysis and death. Fortunately, early treatment of this disease results in a significantly higher chance of recovery. This disease is treated using hyperbaric oxygen therapy in a recompression chamber (Wikipedia, Decompression sickness, n.d.).
Finally, we will be looking at some notable uses of the caisson. The first use of the caisson was in 1840 by Charles-Jean Triger. He was the first to use a pressurized chamber for working and did so to be able to mine coal in the Loire Valley of France. It was during this time that the first known cases of caisson disease became public. Another use of the caisson was during the construction of the St. Louis Bridge in 1868. The St. Louis Bridge is a 1500 feet bridge that spans across the Mississippi River and the caissons used during the construction were lowered to a maximum depth of 93 feet. Almost twenty men died during this project and close to 25% of all workers had experienced caissons disease. The last use case of the caisson we will discuss is that of the Brooklyn Bridge. The construction of this bridge started in 1870 and the maximum depth of the caissons reached almost 80 feet (Ninokawa & Nordham, 2021).
As we have seen caissons have been a very useful tool for many different use cases, it was first used to be able to mine coal in France and it was later used to be able to build the foundation of the Brooklyn Bridge in America. Unfortunately, the caisson also birthed caisson disease, a medical condition through which patients suffer from a variety of symptoms ranging from joint pain to paralysis and even death. But after looking at everything we can conclude that the caisson truly was a very important invention for bridge building in the world.
References
Mann, E. (1996). The Brooklyn Bridge. In E. Mann, The Brooklyn Bridge (p. 576).
Ninokawa, S., & Nordham, K. (2021, September 1). Retrieved from National Library of Medicine: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8682815/
Wikipedia. (n.d.). Caisson. Retrieved from Wikipedia: https://en.wikipedia.org/wiki/Caisson_(engineering)
Wikipedia. (n.d.). Decompression sickness. Retrieved from Wikipedia: https://en.wikipedia.org/wiki/Decompression_sickness
