Directional Boring Equipment: What Machines and Tools Are Used on Oklahoma Jobs

When a bore rig pulls up to a job site in Yukon or Edmond, most homeowners and project managers see a compact machine on a trailer and a support truck, and they wonder how that equipment can possibly install a gas line under a 100-foot driveway without digging it up. The answer is a precisely engineered system of directional boring equipment – the rig, the drill string, the steering head with its beacon, the mud mixing unit, and the locating equipment that guides the operator from above. This guide covers each piece of equipment used on a typical Oklahoma directional boring project, what it does, and why it matters to the quality of the finished job.

The horizontal directional drill rig

Mini-HDD rigs dominate the residential market in the Oklahoma City metro area. Companies like Ditch Witch and Vermeer manufacture the most common units seen on residential Oklahoma jobs. A Ditch Witch JT20 or Vermeer D20x22 represents the typical residential bore rig – compact enough to fit through a standard gate, powerful enough to complete a 200-foot residential bore in soft to medium clay soils in a few hours.

For commercial work – utility crossings, fiber optic runs, water main installations – midi rigs in the 40,000 to 100,000 pound class are used. These machines are transported on lowboy trailers and require a larger staging area at the entry point. They can complete bores of several hundred to several thousand feet and handle product pipe from 4 inches to 18 inches in diameter. For an overview of what this equipment accomplishes underground, see our guide on what is horizontal directional drilling.

Drill string: rods, connections, and the sonde housing

Drill rod quality matters more than most clients realize. Inexpensive rods wear at the connections and can fail in high-torque situations, leaving a section of drill string stuck underground in a partial bore – a costly recovery operation. Quality rods from manufacturers like Ditch Witch or American Augers are built to match the rig’s thrust and torque rating so the string handles the job without premature fatigue.

The bent sub is a short curved section at the front of the string that gives the drill head its steering capability. When the string is rotating, the bend averages out and the bore goes straight. When rotation stops and the string is only pushed forward, the bent sub steers the head in the direction the bend is pointing – up, down, left, or right. The operator controls steering by choosing when to rotate and when to slide, and in which orientation the bend is pointing at any given moment.

Drill heads and bits for different Oklahoma soil conditions

The spade bit is the workhorse of Oklahoma residential boring. Its angled face displaces clay laterally as the drill rotates forward, creating a bore hole that is slightly larger than the bit diameter to allow drill fluid return flow. In hard, dry clay like western Oklahoma’s Tillman County soils, a harder tungsten carbide-tipped spade bit is used to handle the abrasion and resistance of dense, dry formation.

After the pilot bore is complete, a reamer is attached to pull back through the hole and enlarge it to the diameter needed to pull the product pipe. Reamers come in various styles – barrel reamers, fly cutters, and backreamer wings – each suited to different soil conditions and hole sizes. The product pipe or conduit is connected to the back of the reamer and pulled through as the reamer enlarges the hole on its return trip.

Walkover locating systems: tracking the drill underground

The walkover locator is what separates a precision directional bore from a blind bore. Systems made by companies like DigiTrak, SubSite, and Radiodetection are the industry standard. The locator operator walks directly above the drill head, stops over it to take a reading, reports the data to the rig operator by radio, and they steer together toward the exit point. On a well-run residential bore, the drill head arrives at the exit pit within an inch or two of the planned point.

Locating system performance matters for accuracy near existing utilities. When the bore path passes within a few feet of a located electric or gas line, the ability to steer with precision and keep the separation that was planned on paper is the difference between a safe bore and a utility strike. A contractor using outdated or inaccurate locating equipment is a risk even if their rig is modern. For how locating integrates with utility avoidance, see our bore path planning guide.

Drilling fluid mixing and mud recycling equipment

Drilling fluid formulation is more technical than it sounds. Oklahoma heavy clay requires polymer additives to prevent clay from swelling and sticking to the drill string. Sandy or gravelly soils in western Oklahoma require a higher-viscosity mix to carry cuttings back without them settling in the bore hole. Matching the fluid chemistry to the soil is part of what separates professional boring from guesswork.

On larger commercial bores, a vacuum excavation truck (hydrovac) may be stationed at the exit point to quickly capture and contain returning fluid and spoil. This is especially important on jobs where fluid escape into a drainage channel, waterway, or street would create an environmental or permit issue. Proper fluid management is part of professional bore site operations.

Support equipment: vacuum excavation, trailers, and tooling inventory

Vacuum excavation – using pressurized water to break up soil and vacuum it into a tank – is used to safely expose existing utilities near the bore path before drilling begins. This is called potholing or daylighting, and it is the safest way to visually confirm the depth and position of a buried gas, electric, or water line when the 811 locate marks put it close to the planned bore path.

A well-equipped crew also carries pit lining material, safety cones and traffic control equipment if the job is near a road, and the full range of product pipe fittings for the utility being installed. Showing up to a job without the right tools because they were left at the shop adds cost and delays that professional contractors avoid by maintaining a complete mobile toolkit. If you are evaluating whether a contractor is properly equipped for your job, ask them specifically what locating system and mud mixing equipment they bring to a site.

Product pipe and conduit pulled through the bore

HDPE pipe is preferred over rigid materials like PVC or steel for directional bore installations because its flexibility allows it to follow the curved bore path without cracking or kinking. It is available in a range of pressure ratings and sizes. For gas service lines in Oklahoma, yellow-stripe PE2708 or PE4710 HDPE in 1-inch to 2-inch sizes is the standard product pulled on residential and light commercial jobs.

For water main installations, blue-stripe HDPE or fusible PVC pipe in larger diameters is used. For fiber optic boring, an HDPE conduit (innerduct) is pulled first, and the fiber cable is blown or pulled through the conduit after installation. For more on specific utility applications, see our guides on fiber optic boring, underground gas line installation, and trenchless water line installation in Oklahoma.