Knowing the drill

CENTRAL WESTERN AUSTRALIA. Byrnecut Australia keeps the dirt moving at Northern Star Resources’ Jundee gold mine, and the latest automated underground drilling technology is helping the contractor stay ahead.

Keith Law isn’t coy about the remoteness of the Jundee gold mine. “We’re pretty much smack-bang in the middle of Western Australia,” says Law, the project manager for Byrnecut Australia’s contract at the operation. “We are a bit isolated here.” Located 50 kilometres northeast of the tiny town of Wiluna and 1,150 kilometres by road or a two-hour turboprop flight northeast of Perth, Jundee is the definition of remote. But since production started in 1995, the mine has made the trek worthwhile for mining companies, producing more than 7 million ounces of gold. Northern Star Resources bought Jundee from the mine’s third owner Newmont in 2014, a cornerstone of a series of acquisitions affirming its spot as Australia’s third-largest gold producer. Ever since, the company has steadily revealed new mineralization through aggressive exploration drilling. “Under the original plan, Jundee would have been on its way to winding up right now and closing the gates,” Law says. “Northern Star have found more orebodies and more work and at the moment it’s got 10 years-plus mine life.”

During the last quarter of 2016, Jundee churned out 59,527 ounces of gold – nearly half of the 124,871 ounces Northern Star produced during the quarter. Byrnecut Australia is responsible for all underground mining and fleet maintenance at the operation, while Northern Star undertakes mine and blast design, production geology, survey, geotechnical and mine planning. Byrnecut Australia has had a presence at Jundee for more than 15 years with the mine’s various owners, and the current contract with Northern Star is one of the contractor’s biggest active projects. Thriving, not surviving During a downturn that many mining contractors have simply tried to survive, Byrnecut Australia has thrived. Managing director Pat Boniwell cites several factors that have played into the company’s recent success.

Byrnecut Australia

Byrnecut Australia, part of the 2,500-employee Byrnecut Group, was established in 1987 as a specialist underground mining contractor. Today the company is Australia’s largest mechanized mining contractor, providing underground mining services in several major projects across the country. Byrnecut Australia’s contract works include mine development and production and project management services, raise drilling, boxhole boring, shaft boring, shotcreting construction and mine design and feasibility work. The contractor excavated 56.1 kilometres of development and delivered 11.2 million tonnes of ore for clients in 2016, drilling 988,937 metres of production and trucking 50.7 million TKMs in the process.

“Our business is more weighted in gold, which has helped since gold’s weathered the downturn better than other commodities,” Boniwell says. “More important than that we have talented, experienced employees and great clients running really strong operations. We’re backed up by strong, long-term suppliers, and those relationships are extremely important to us. “We encourage innovation from our suppliers, which helps us remain competitive and continue to add value to our clients. The point at which we cease to do that, we cease to exist as a contractor, so that’s critically important. We’re always looking for the next opportunity to implement state-of-the-art technology to improve our operations, either from a safety, productivity or cost perspective.” Byrnecut has relied on Sandvik drill rigs to achieve development and production targets in projects across Australia and abroad for almost three decades. “As an organization I think we bought our first drill off Sandvik in 1988, so it’s been a long relationship and on the whole a pretty healthy one, I think for both parties,” Boniwell says. “We’ve stuck with the Sandvik product, particularly in the drill space, for a long period of time now, for all of that nearly 30 years.” Next-generation drilling Byrnecut Australia trialled the latest intelligent Sandvik development jumbo, Sandvik DD422i, at another Western Australia contract in early 2015, with a primary aim to validate its new drilling and cabin concepts.

Sandvik DD422i

Sandvik DD422i is an intelligent control system based development drill engineered to deliver peak performance, accuracy and reliability for underground drilling and small-scale tunnelling. The jumbo features a wide range of automatic drilling functions to increase productivity and cut costs.​ Developed specifically for intelligent development drilling, Sandvik DD422i is compatible with Sandvik AutoMine Remote Monitoring and Sandvik AutoMine Drilling concepts. Equipped with Sandvik Intelligent Control System Architecture (SICA), the rig has features for fully-automated face drilling, optimized drilling and boom control systems and comprehensive tools for drill planning, reporting and analyses.

Boniwell admits the contractor may have initially overlooked the value the new rig’s technological innovations would prove to deliver. “At first it was more about the new platform and getting better reliability,” he says. “What became apparent pretty quickly was that in this new product the integration of the latest technology into the robust drill platform had been done better than ever before. That gave us some confidence to start pushing the automation side, the drill control side, less machine intervention with the manual control, and marrying those together. The operator interface is more intuitive, so our drillers accepted the unit and the technology.” Byrnecut Australia brought the drill to Jundee later in 2015 to test its automation benefits. “It didn’t take long for us to realize that this drill was going to affect our business in a

positive way and give us big advantages in cost and productivity,” Law says. During a three-month trial at Jundee, Sandvik DD422i drilled in excess of 60,000 metres monthly. Consumable costs fell by 25 percent thanks to longer tool life and Byrnecut Australia halved its overbreak. The new drilling control system significantly improved productivity and accuracy, adjusting dynamic drilling power based on rock conditions and eliminating the need for operators to modify any drilling parameters. More than a year later, Sandvik DD422i remains responsible for all development at the mine. “Being able to extremely accurately control the level of overbreak within designed tolerances has been fantastic,” Boniwell says. “The additional savings we’ve realized through less ground support time, cycle time, less scaling, those kinds of things, has been better than we expected, and then the final piece has been we’ve been able to realize gains through using automation between shifts, so with no operators present we’ve been able to consistently have the machine drilling in auto mode. “Every additional metre you can get on auto drilling is just straight to our bottom line from a productivity and dollar sense.” Embracing automation Sandvik DD422i drills as many as 20 holes during a shift change at Jundee, and Byrnecut Australia also takes advantage of its automation during blasting and ventilation times. Operators use some automated functions during their shifts to achieve more consistent drilling results. Ryan Selfe, a Byrnecut Australia jumbo operator, quickly embraced the new drill’s technology and appreciates benefits that save him time, including no longer having to mark up the face before he starts drilling. “All I’m doing is putting in a cross on the face and a backsight, and then write all the measurements in there in the computer system, and you’re drilling sort of within five minutes of plugging in,” Selfe says. “It’s very user-friendly.” Sandvik DD422i creates reports that simplify operator training and help address any potential human drilling performance issues that may arise. “The reports it generates are just mind-boggling, more information than you could ever want of every cut, every hole that the machine drills,” Law says. “We can pull up every profile, every hole depth, a 3D model of the cut that has been bored, so we can sit down with the operators if things aren’t working and develop a good plan to fix any problems we are having with the cuts.” Based on its success at Jundee, Byrnecut is already introducing Sandvik DD422i in other contracts at home and overseas. “We’re getting a better result, we’re getting nicer-looking drives, our overbreak’s less so we’re not trucking dirt that we shouldn’t be trucking, the ground support’s better, easier to put up,” Law says. “We’re taking a lot of the human error out of the mining site, and automation is just this key. Based on our experience to date, Sandvik DD422i will be the jumbo fleet of the future for Byrnecut. We need something to stay ahead of the competition and this rig provides that.”

Jundee gold mine

Jundee gold mine is located 50 kilometres northeast of Wiluna and 1,150 kilometres by road or 800 kilometres as the crow flies from Western Australia capital Perth. Since production started in 1995, the mine has produced more than 7 million ounces of gold and currently has a 10-year mine life. Jundee is one of four Western Australia gold mines operated by Northern Star Resources, which is on track to produce between 485,000 and 515,000 ounces in financial year 2017.