On July 24th 2008, a milestone was reached in the construction of the new Welcome 1,000,000 gallon tank. After months of construction, the bowl of the tank was ready to be raised into place at the top of its concrete pillar.
The new Welcome tank was one of a pair of tanks being constructed at the same time, with the other being Hickory Tree. Having two tanks built at the same time was a first for Davidson Water, but even more groundbreaking was the type of tank being built across the road from our water office.
Until construction started, all of our elevated tanks were formed completely from steel. The new Welcome tank type is called a composite tank, and utilizes a pre-stressed concrete pedestal with a steel bowl at the top. This type of tank requires less maintenance since there’s less steel, and the concrete pedestal under the tank houses the ladder needed for inspection purposes. So the tank has more modern characteristics to it, than the standard tanks one typically sees.
When constructing a composite tank, the concrete pedestal is built first. Then the steel bowl is assembled around the bottom of the tank. Once the bowl is assembled, it is raised into position using hydraulically operated cables mounted at the top of the pillar. Once the bowl is in position, it’s secured in place and construction begins on the very top of the bowl. Even though once the bowl is raised the tank looks finished, the tank won’t be ready for service for several more months.
It only took a couple of hours to raise the bowl in position, and the sight attracted a number of people who watched the event take place. Below are some pictures taken during the raising procedure.
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