HDD DEMAND

摘要

From telecoms in Europe and China to gas distribution pipelines in the US , the need for horizontal directional drilling (HDD) remains strong in many areas of construction. The method uses a rig at ground level to launch a pilot bore that drills an arc along a planned underground trajectory, usually sweeping beneath an obstruction such as a road, river or railway. A reamer is then connected to the drill rod at the exit hole and reverses back towards the rig, opening up the bore to create a hole large enough for a new pipeline. This pipeline is then connected to the back of a cleaning reamer and effectively slides into the new path. The lack of need for launch pits and increasing productivity of machines has increased the popularity of the method which has been widely used since the 1970s and'80s.