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www.rockproducts.com ROCK products • March 2018 • 57 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 man- agement 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 blast- ing 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. "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 azi- muth 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 operat- ing 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 Flex- iROC 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 accountabil- ity 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. 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 prob- lem," 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. "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 Charles Selman. Billy Phillips, Quarry Services co-founder.