HDD Machine and accessories

Horizontal directional drilling (HDD) machines are steerable, trenchless drilling rigs for the installation of pipes, conduits, and cables underground in a shallow arc. They are commonly used for installations below waterways and roadways to avoid disturbing the ground above.
Horizontal drilling machines are typically heavy-duty vehicles fitted with track drives, operator controls, and drilling machinery. Materials used for pipes include PVC, polyethylene, polypropylene, ductile iron, and steel.

Operation
Directional drilling machines install both small and large diameter lines (3 to 48 inches). Installation is typically a two-step process. The first step is to use a drill head to drill a one- to five-inch pilot hole at an angle, using the ground as reference. The second step involves replacing the drill head with a reaming device such as a fluid-assisted drill, a high pressure fluid jetting system, or a dry bore system to enlarge the hole to the desired size. As the reamer is pulled back the pilot hole is enlarged and pulls the pipe or conduit back with it. For larger pipes an additional step of reaming will be required. The final size of the drilled hole is 50% larger than the pipe diameter to drain drilling fluids and to accommodate the bend radius of the pipe.
Directional drilling machines come in a range of sizes, with the largest machines capable of drilling to depths of 200 ft. and lengths of 6,000 ft. Horizontal directional drilling machines are divided into three categories large-diameter HDD (maxi-HDD), medium-diameter HDD (midi-HDD), and small-diameter HDD (mini-HDD). There is no significant difference in the operation of these systems. The categories represent the drive length, depth, torque and pullback capabilities of each system.