Horizontal Hole openers, also known as HDD reamer, are used to enlarge the diameter of a pre-drilled hole. They are custom built to specification, and come in a wide variety of sizes. HDD is used when trenching and excavating is not practical. This drilling technology allows for a steerable trenchless way to drill underground. There are three stages, the first stage is to drill a small diameter pilot hole. The second stage is enlarge the hole with a larger diameter cutting tool called an HDD Reamer, Rock Reamer or Hole Opener. The third stage is inserting the casing pipe or other product into the enlarged hole.
