Horizontal Directional Drilling

HDD is a steerable means to install pipes, conduits and cables using a surfaced drilling rig. This technique is used where long distances are involved such as river crossings or highly developed areas. HDD lends itself best to soft-ground situations and is not recommended for rock or heavy-gravel soils.

HDD is a three-step process in which a fluid filled pilot bore is drilled without rotating the 'drill string'. Monitoring of the drill string is done with a down-hole survey tool. The pilot bore is then enlarged to the diameter needed for the pipe being installed with an enlarging device that follows the track of the pilot bore. The final stage is when the final pipe is pulled back along the bored hole until properly situated.

                      Auger Boring                                           Horizontal Directional Drilling                                     Pipe Bursting                                    Re-Lining