Georgia Drilling Contractor Provides Computer-Based Confidence in Every Hole.
By Mark S. Kuhar
Charlie Selman and long-time associate Billy Phillips, a driller and drill technician, had sensed a shift coming in the quarry industry’s operating model that would place a premium on efficiency. In 2008, when the recession bit hard into the U.S. construction economy, Selman and Phillips confidently founded Quarry Services LLC of Marietta, Ga.
|CEO Charlie Selman with driller Corey Desrosier.|
Selman is CEO of the company. Phillips is operations manager, serving in a number of roles that include lead driller trainer and maintenance director of the company’s current workforce of 20 drillers and fleet of down-the-hole (DTH) blasthole rigs from Epiroc – Part of the Atlas Copco Group.
Selman said the reason for Quarry Services’ success as a blasthole-drilling specialist is its ability to offer aggregate customers the most precisely placed, highest quality holes possible.
From the beginning Quarry Services has preferred Atlas Copco for its drill rigs. “We chose Atlas Copco because they ‘got us,’” he said, describing the company as “a long-term, reliable partner, continuously working alongside us to provide us with solutions that support our business model – sustainability through accountability.”
Selman and Phillips had also anticipated the development of the SmartROC line. The commercial availability of the SmartROC D60 was eagerly welcomed. They had attended its prototype demonstrations in Missouri and in Australia. “I wanted to buy them right then,” Selman said, “but they weren’t for sale yet.”
They were exactly the rigs Quarry Services had been waiting for.
Since 2016, Quarry Services has acquired five SmartROC D60 units with one more on the way. Other units in the Quarry Services fleet will be replaced with SmartROC D60 rigs as each comes up for scheduled rotation.
Epiroc District Manager Paul Colvin said, “Quarry Services is a prime example of a drilling contractor leveraging SmartROC capabilities to their fullest.”
Precision Means Blast Control
Selman said, “Before 2008 aggregate producers were more production-oriented. Now companies have to be efficient to be sustainable. The recession brought clarity to that.”
Some companies are now preparing for the uptick in demand by widening their pits. One of the largest problems they are facing is that decades of high-production quarrying meant diving deeper into an already-exposed resource rather than set aside production time to remove overburden. Today, when quarries return to pit development, they discover challenges that hadn’t existed previously.
One pit Quarry Services is working for today is a prime example. The operation had been established in a remote, back-wood location accessed by one long, gravel road. Today the pit shares boundaries with an industrial complex and its warehouses, with paved county roads on either side of the pit. An interstate highway passes nearby. A posh residential neighborhood has been built not far from what had been an inactive area of the quarry property.
Blasting contractors working deep in a pit can rely on the pit’s own walls to assist in containment. Upper levels of the pit require greater finesse of the pattern design to maintain desired fracture while minimizing back-break and other environmental/safety hazards. The blasting contractors that Quarry Services works with do this well, but containment of ground vibration and air over-pressure require precise management to minimize the effects of wasted explosive energy felt by the quarry’s neighbors.
Selman said: “The SmartROC rigs’ Hole Navigation System (HNS) and measure-while-drilling capabilities allow the blasting contractor to design the blast with minimal wasted energy. The customer can achieve the most efficient fragmentation results while being the best possible neighbor they can be.
“We are accountable for one thing and one thing only, which we do better than anyone in the industry – precisely placing and drilling the highest-quality holes.”
Charlie Selman, Quarry Services CEO
“It has been my experience that, more often than not, it’s poorly executed drill designs and the limitations of older drilling technologies that cause blasting energy to be wasted,” Selman said.
One essential tool the SmartROC HNS technology delivers is the ability to drill precisely angled holes that accommodate any face profile regardless of the rig’s own orientation. This gives a blaster the freedom to design a blast utilizing any azimuth or angle corrections to optimize blast performance. The more precisely blasters can place accurately drilled holes, the more control they have for managing containment and shot characteristics. Therefore, quarries turn to drilling specialists like Quarry Services.
Selman explained, “As blasthole drilling specialists, we are accountable for one thing and one thing only, which we do better than anyone in the industry – precisely placing and drilling the highest-quality holes.”
Sustainability Through Accountability
Quarry Services’ 20 drillers are skilled professionals operating machines that proved themselves to be the best match for precision drilling requirements of Quarry Services customers.
About 70 percent of the quarries are granite pits. The rest are limestone. Most of Quarry Service’s customers require holes 5 ¼- to 5 ¾-in. in diameter, to depths on average ranging from 45 to 55 ft.
Selman said he likes top hammers, “which have a great deal of flexibility,” but for holes over 4 in. and at depths greater than 45 ft. he prefers down-the-hole (DTH) rigs.
Quarry Services assigned this work to 20 Atlas Copco ROC L8(25) DTH rigs until 2012, when it began rotating out the L8 rigs for their electronic-over-hydraulic successor, the FlexiROC D60 based on the proprietary Rig Control System (RCS). The computer optimized rigs run on less fuel with increased uptime. And automated rod handling and drilling provide greater operational efficiencies throughout the shift.
Selman liked the increased precision and economy of his FlexiROC D60 rigs, but the SmartROC D60 is what he had been waiting for to support his business model. “It’s a model built on accountability,” he said. “I’ve introduced accountability to every aspect of the business, but especially the holes. Until there were computerized rigs, hole accountability used to be based on subjective impressions. Those impressions can vary widely from driller to driller. With SmartROC rigs, accountability is based on objective facts, on hard data. We have metrics to account for every foot of every hole.”
This is fundamental to sustainability, Selman said. “Bottom line, we only get paid for the holes we drill to plan. We want to get paid for every hole we drill.”
Phillips’ son Calup is the lead driller in this customer’s granite pit near Atlanta. Calup prepared for the shift change, busily dressing carbides on a spare bit from a stand next to the rig, which was completing a hole on AutoDrill at a rate of about 2 ½ ft. per minute.
|Billy Phillips, Quarry Services co-founder.|
Driller Corey Desrosier waited his turn with the rig. Desrosier said although he prefers the SmartROC D60, he was perfectly comfortable in the D60 rig’s “lever” rig predecessor, the ROC L8 he began his career in. “I’ll drill in either one, no problem,” he said. Switching to a computer-optimized rig was not difficult for him. “I did three days of supervised drilling in it before drilling on my own,” he said.
The pattern of this older, 52-ft.-high, vertical-walled bench deep in the pit consisted of 5 ½-in. ,m .diameter blastholes sub-drilled 3 ft. to a total depth of 55 ft. Originally drilled with no angle from vertical, the bench wall had significant back-break beginning about halfway up, leaving uncertain surface conditions at the crest. Enhancing the operator’s safety, the SmartROC D60 adds more than 10 ft. of horizontal reach from rig to hole. On a bench with 10-ft. burden, that’s up to 20 ft. of distance from the wall’s crest.
Looking to reduce back-break of future shots, the blaster has given this pattern a 5-degree cast. Experimenting at these depths provides precautionary containment from the opposite pit wall. So far, the angle drilled precisely to plan by Quarry Services has been giving the blaster good results, effectively reducing back-break, improving consistency of fracture and leaving the crest with improved geometric support for the drillers, all while offering well-managed containment.
|A Quarry Services SmartROC D60 drill rig begins the next blasthole pattern. They count on precision to create controlled fragmentation, shown here in the previous blast’s rock on the floor below.|
The SmartROC D60 rigs not only locate and drill the holes exactly where planned but also help the drillers communicate – another skill Quarry Services drillers do better than anyone.
Selman said that while he would never presume to tell a blaster his job, he does want to soft-sell his company’s cutting-edge capabilities. “Customers can’t ask us to do what we’re capable of if they don’t know what we’re capable of,” he noted.
A SmartROC D60 rig’s capabilities include high-precision GNSS-location, AutoDrill, automated rod handling, measure-while-drilling, hole logging and reporting. Rig Remote Access data and line-of-sight wireless drilling from a BenchREMOTE control station are other features making it the market’s most precise, most versatile DTH rig.
With a SmartROC D60, the driller can make an on-the-spot, computer-optimized adjustment to the blasthole pattern. Drilling parameters are recorded and logged. Everything about that hole is communicable to the blaster, who uses the information to review the adjustment and consider alterations to subsequent patterns.
Quarry Services also utilizes a face-profiling system based upon stereophotogrammetric imaging, a new technology, used in conjunction with SmartROC software.
The software compares multiple photos of the same location from differing angles, to create a 3D digital image of the bench and proposed blasthole placement. Quarry Services is using the software to identify where a driller might have to make hole adjustments before ever tramming onto the bench.
|Automated drilling cycles mean the driller is freed up to perform other tasks he is accountable for. While this SmartROC D60 busily drills away in the background, this Quarry Services’ driller is dressing another bit’s carbides.|
While the shift change was taking place on the bench, Charlie Selman’s son, Charles, was in the office studying the computer-generated images of a blasthole layout in another area of the pit. While looking at the holes, Charles noticed something at an inside corner for this bench that the blast planner might want to know. He made slight adjustments to the hole placements and prepared a copy to email to the blaster for review and approval.
Selman is looking forward to even more SmartROC-based capabilities. Although the SmartROC D60 can already be wirelessly operated from a BenchREMOTE control station, Selman is anxious for teleremote drilling. “I’d like to see multiple rigs controlled long-distance, maybe by a single driller,” he said. This capability exists for Epiroc’s largest drill rigs, its high-production Pit Viper line. “We’re really still at the beginning of where drilling is going. I believe there is so much more that can be done with the SmartROC yet.”
Information for this article courtesy of Epiroc – Part of the Atlas Copco Group.