Key Takeaways • Horizontal directional drilling (HDD) installs underground utilities in three stages: pilot bore, reaming, and pullback. Each stage serves a distinct function and requires different equipment configurations. • The pilot bore is steered using a sonde transmitter tracked by a walkover locating system, allowing the operator to navigate around existing utilities and maintain the designed bore path. • HDD installs water, sewer, gas, electrical conduit, and fibre
