'It's like threading a needle': Boring 180-foot long hole--sideways--under the Main Street railroad crossing in Du Quoin for the new downtown water line

As work continues to install new 8-inch water mains in downtown Du Quoin contractor Korte & Luitjohan of Highland, Ill. and their subcontractor are in the middle of boring beneath the Canadian National Railroad Main Street crossing in Du Quoin. It is a continuous bore 180-feet in length. "It's like threading a needle," said one of the workers. Not only do you have to get it right" down in a 10-foot deep pit, but you have to miss other water and sewer mains and fiber optic communication cables along the way.

With the basic boring procedure, a boring machine pushes a casing pipe sideways through the ground while an auger is continuously retracting spoils from inside the casing pipe. After the first 20-foot length of casing pipe has been pushed through the ground, another length of casing pipe is welded onto the previously installed piece and pushed through the ground. This procedure continues until the 180-foot length of casing pipe is installed. The line and grade must be maintained during the installation process. This is accomplished by pulling the auger out of the casing several times, and using a transit or laser beam to verify the line and grade, making adjustments as needed.