Excerpted from an article written by Allison Hatfield that appeared in The Texas Contractor, April 2, 2001.
TEXAS CONTRACTOR RENTS ROCK DRILL ATTACHMENT
From our June 2001 newsletter

Construction contractors are faced with a growing number of project challenges, including environmental issues, employee safety, on-time completion, financial considerations and driver frustrations. Technology is helping solve some of those problems, and rental houses are helping bring that technology to contractors.

Tramac rock drill attachment expedites work on U.S. Highway 277 in Texas.

Allen Keller Co. of Fredericksburg recently discovered first-hand how a new excavator-mounted rock drill attachment saved time and money when it rented the machine and put it to the test in an extensive highway reconstruction project in southwest Texas.

When work began last September on the final phase of the reconstruction of US-277, an eight-mile stretch that runs through Loma Alta in Val Verde County, the contractor knew time was of the essence. The project encountered several obstacles in the planning and approval stages, including the concern of environmentalists because the highway bisects a nesting area for an endangered bird. “Once work began, we did something very unusual. We closed a US Highway.” The location of the road made it physically and fiscally difficult to route traffic around construction, so the state designated an alternate route, says Robert Parker, Del Rio Area Engineer for the Texas Department of Transportation (TxDOT), which “means work needs to be done quickly, so we can reopen this roadway,” Parker says. “This thing has to be on the fast track.” An excavator-mounted rock drill rented from Air Master Equipment in Odessa helped put it there.

Allen Keller specializes in rock excavation. The company received the $8.2-million contract to widen and reconstruct the Loma Alta portion of US-277 highway in March 2000. The job, which includes grading, base, structures, surfacing and the
addition of shoulders north of Loma Alta, involves a tremendous amount of drilling and blasting. “This is a big job for us,” Kory Keller says. “We had about 100,000 cubic yards of rock to excavate.”

A Need for Speed
“We were looking to expedite the drilling process, as it was critical to the whole project,” Keller says. “I was looking to speed things up in that area any way I could.” So Keller turned to Air Master, a company that specializes in compaction and drilling.

Bruce Peeler, president of Air Master, has a sizable rental fleet that includes a John Deere 690 excavator coupled with a Tramac rock drill attachment. The Tramac is ideal for pipeline trenching, utility work, anchoring and rock bolting, rough terrain construction and long-reach work. It utilizes the Montabert Drifter with the ability to sense the hardness of the material it comes in contact with and adjust feed pressure, rotation and even direction.

Peeler first introduced Keller to the Tramac drill when the contractor was working on a $3.3-million runway extension at the Del Rio Airport. “We told them that the Tramac can do the work two and a half to three times faster than an air trac drill with substantial cost savings,” Peeler says.

The US-277 project involved pre-split drilling, as well as roadway production hole drilling, Keller says. “The pre-split we did with regular drills, but we used the Tramac for the production holes.” The drill was so quick that within a few days, Keller had all the holes it needed to proceed with blasting. Allen Keller drilled thousands of holes approximately 4 inches in diameter and averaging 10 feet deep during the three months it rented the drill, a process that may have taken up to nine months with an air trac drill, and because “this drill is a one-man operation, it cut labor expenses,” Keller says"... If you had to employ three air tracs and two men to run each one, you can see how the Tramac can save you time and money,” Peeler says. “This is a high production machine.”

Attachment Advantages
One of the biggest benefits of the attachment is that it provides versatility by allowing a contractor to use his excavator for loading, trenching and demolishing, in addition to drilling. “There has been a big push for consolidation of assets and maximizing utilization of assets,” Peeler says. “When you have a dedicated drill, that’s all the drill can do. A drill might run four or five months out of the year. You cannot use the machine the rest of the time, but with an attachment, when you are done drilling, you can make good use of your excavator.”

Another benefit of the excavator attachment is that the operator works in an enclosed cab, so he is exposed to lower noise levels and is somewhat removed from dust and other hazards of the drilling operation. This is bound to please the Mine Safety and Health Administration (MSHA) and the Occupational Safety and Health Association (OSHA).

A third benefit of the drill is its flexibility. It reaches places that normally would not be accessible, according to Air Master’s Peeler. It can drill more holes before the drill must be moved, and the holes can be drilled deeper. “The Tramac has a long enough tower that you can drill down 21.5 feet in a single pass without adding steel. With a traditional drill, you would have to add steel at least once to get to that depth,” Peeler says.

The Tramac incorporates technology that allows the drill to sense the hardness of the material below the earth’s surface. This feature allows the drill to reverse the feed automatically if it hits soft material that plugs the bit, thus allowing the bit to clean itself and automatically begin drilling again, all without the involvement of the drill operator.

“For example,” Peeler says, “you may hit clay seams 8 to 10 feet below the surface. You wouldn’t know you’ve hit until you are already in trouble, but the Tramac knows instantly and will work through the problem automatically.” This feature impresses Keller.

“You can see the drill react when it hits clay,” he says. “It will sort of change its strategy and get to rock again. It works very well.”