Trans,Alaska,Oil,Pipeline,The, education Trans Alaska Oil Pipeline
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The pipeline is a tube of 1/2-inch thick steel with a diameter of 48 inches and a total length of 1280 kilometers. After 5 years of surveying and geological sampling, the Alaska pipeline project was started March 27, 1973 and was completed May 31, 1977, at the mind staggering cost of 8 billion dollars. More than 10 times the original estimated cost, this was the largest privately funded construction project of its time. At the peak of construction there were over 21,000 men and women working 24 hours a day in some of the harshest weather conditions on earth and during the construction phase 31 people were killed.As the pipeline runs both above and below the ground, this presented some very unique and challenging problems that had to be overcome. One of the first problems that had to be considered was the fact that the crude oil that was pumped from the Prudhoe Bay field, from a depth of 10,000 to 20,000 feet deep and was approximately 145 to 180 degrees Fahrenheit. The crude oil had to be cooled before it was pumped into the pipeline to avoid damaging the permafrost in the buried pipe. This was achieved by encasing the pipe in an insulated, refrigerated ditch.The elevated sections of pipeline are built in a zig-zag pattern, since pipe shifts around far more easily above the ground than it does when buried, and this allows the pipe to move more freely due to temperature related expansion and contraction. Each length of pipe is set in place on vertical support members that utilizes special shoes allowing horizontal and vertical movement, and crushable blocks are used to absorb sudden shocks due to earthquakes or avalanches. To disperse heat from the oil that is flowing through the elevated pipe, that would cause the vertical supports to melt through the permafrost and causing the supports to sink and thus damaging the pipeline, radiators were built into vertical supports that use passive convection of anhydrous ammonia to disperse the heat from the flowing oil and decrease the convection of heat through the pipeline. Fiberglass insulation that is four inches thick surrounds the above ground pipeline to keep the oil warm enough to flow even on the coldest winter days. The pipeline crosses over 800 rivers and streams and three mountain ranges. The first flow of crude oil moved through the pipeline began on June 20, 1977 and reached Valdez on July 28, 1977, and oil flowed through the pipeline at a speed of about 5 to 7 miles per hour, it takes about five to six days for oil to complete the journey from Prudhoe Bay to Valdez.
Trans,Alaska,Oil,Pipeline,The,