Thomas W. Schmidt, Barbco, Inc., and Drake Barbera, AccuLine Underground, USA, discuss a challenging guided auger bore project completed in Tennessee.
I
n February 2021, the AccuLine team was called on a 36 in., solid rock crossing in Dayton, Tennessee. AccuLine was notified that another contractor was set to attempt the crossing with a disc cutter head, but was not able to, by the time the jacking pit was completed. The overall project had no more time to wait, and became a rush to start. When reviewing the project details, the team was informed of the necessity that the bore was completed on the line and grade of the engineered plans, 0.15%, with no tolerance permitted. The AccuLine team made the decision to install a line-of-sight pilot throughout the crossing to maintain grade and to determine the ground conditions throughout the crossing, changing a rock SBU crossing to a Guided Auger Bore. The team, which included Drake Barbera, Clay Gillilan, and Joshua Knotts, set up AccuLine’s
Figure 1. Close-up of AccuLine’s custom designed Pioneer One Hammer Tool.
27
