ForConstructionPros.com

Push, pull, turn, pump - the basic tasks associated with horizontal directional drilling (HDD) sound pretty straightforward. Yet maneuvering around buried obstacles you can't see, and boring under existing structures/natural masses you can't move - often in less than ideal soil conditions - is anything but. Without the appropriate torque, pullback, horsepower and drilling fluid mix/flow, even a basic bore can turn into a frustrating and costly venture with inadvertent returns, locked up holes and damaged and/or lost tooling and drill pipe.

HDD rigs are officially categorized according to pullback force. And torque has historically garnered all the hype and attention. But matching power to the project goes beyond these two high-profile specs.

"It's about balance," says Richard Levings at the Ditch Witch organization. "[It's a] balance between torque, pullback, horsepower and drilling fluid. It's about matching the entire system to a job. A good directional drill will have a balance of torque, pullback and mud flow with sufficient horsepower to drive them all simultaneously."

Torque and pullback
When considering a new machine, take a look at the specifications (torque, pullback, horsepower, pump capacity). Is there any one number that is extremely high?

"If there is, ask questions," advises Levings. "Do some research with the dealer to determine if, for example, there is enough horsepower to drive any unusually high specifications. Also talk to contractors who own the same or similar models. Let them offer guidance."