Have you ever tried digging a square hole?
Hand-dug wells are a lot easier to dig in a round shape. Before mechanization, well diggers would suspend themselves by a board attached to a rope, which was attached to a tripod above the hole. To make the hole they simply spun around on the rope, digging in until their arms reached out a certain distance. When the well was finished, a stone wall could be built around the inside above the bedrock layer, forming two arches. This compresses the stones equally, creating a very strong structure.
Modern wells are drilled using giant drill bits, like this:
The rotary action of the drill makes the hole round. Once complete, the well can be lined with pipe to create the same arch effect as the stone walls in older wells. Since no one has to go inside the well, the hole can be a lot smaller.
Posted 4446 day ago