Boca Enterprises, Hagerhill, Kentucky, has developed a reputation for completing difficult horizontal directional drilling (HDD) projects, often jobs that other contractors declined to attempt.
Boca owner Kirby Bowling recognized when he started his underground utility construction business in 1996 that the rocky soils of the rugged hill country of eastern Kentucky would be challenging, and that he should be prepared to excavate and bore in hard, rocky soil conditions.
"We do every kind of underground utility construction," said Bowling. "Gas, water, sewer, telephone, and cable television. In 2009, we did a lot of gas, but with stimulus money becoming available, we are doing more water and sewer in 2010."
As the company's business grew, Bowling began looking for a directional drilling machine that was relatively compact and could tackle the tough conditions his crews encountered on almost every job. He wanted an economical unit that could drill in rock without needing a mud motor and the high volumes of drilling fluids. Ideally the same machine also could operate in "normal" soil conditions.
The solution was a Ditch Witch® JT2720 All Terrain (AT) machine Bowling purchased in 2001, and it has been the company's workhorse ever since.
The 27,000-pound pullback drill unit is equipped with the Ditch Witch organization's exclusive dual-pipe All Terrain drilling technology. The inner rod drives a rock bit while the outer pipe steers the downhole drilling tool for drilling pilot holes, and also provides rotary torque during backreaming. The mechanical drilling system delivers maximum downhole horsepower and operates on low volumes of drilling fluid. In addition to rock drilling, AT equipment is productive in almost every type of soil.
As Boca Enterprises grew, a new, larger, more powerful, rack-and-pinion JT4020 AT unit was added in 2009.
A recent project demonstrates the versatility of the All Terrain system.
An extension of water service in Knott County, Kentucky, required one segment of pipe to cross Carr Creek Lake near Hindman. The crossing would be 1,050 feet under the lake, which reached water depths of 45 feet, with the bore path being 20 to 25 feet below the floor of the lake.
Primary contractor G &W Construction, Morehead, Kentucky, selected Boca Enterprises to make the HDD crossing.
To complicate the installation, surface features required the entry of the bore to be on the side of a mountain where a setup position for the drill unit was constructed. From the position of the entry point, the entry angle of the pilot hole was at a 50-percent downward grade, which then had to level off to proceed under the lake to the exit point on the opposite side.
The larger JT4020 AT was used on the project because its greater power provides the capabilities to pull longer runs of larger-diameter pipe than the smaller model.
The 1,000-plus-foot pilot bore was drilled with a 6.5-inch-diameter Sandvik Rotary Tools roller cone bit offered by the Ditch Witch organization. Subsurface conditions included sandstone and some limestone. Progress of the bore under the lake was tracked from a pontoon boat with a Ditch Witch Electronics 752 Tracker. A remote antenna was attached to the receiver to extend the antenna below the surface of the water and get closer to the beacon's signal.
The pilot hole was enlarged with 12- and 16-inch roller cone backreamers, and the length of 12-inch HDPE pipe was pulled back behind the 16-inch backreaming pass.
The JT4020 AT has 40,000 pounds of pullback, 5,000 foot-pounds of spindle torque, and spindle speeds to 250 rpm.
The JT2720 AT produces 27,000 pounds of pullback, 3,200 foot-pounds of spindle torque, and spindle speeds to 225 rpm.
Each of the self-contained models is mounted on tracks.
All Terrain technology enables both machines to drill in rock and other difficult conditions that are beyond the capabilities of other machines of comparable size and power ratings.
Bowling said that during its first years of operation, Boca Enterprises served primarily as a specialist subcontractor, but has reached the point that it now bids jobs as the primary contractor. Over the years, the amount of directional drilling on projects has increased, and today about 80 percent of pipe and cable the company installs is with HDD.
Ditch Witch® equipment is manufactured by The Charles Machine Works, Inc., Perry, Oklahoma, a leading producer of underground construction equipment including trenchers, vibratory plows, horizontal directional drilling equipment, compact excavators, skid-steer loaders, excavator tool carriers, vacuum excavators, and related products.
