February 9, 2022
Quaint colonial timber houses. Handsome federation-style brick pubs. Vibrant bougainvillea and poinciana trees. Ravenswood could almost be any Australian small country town. Almost, but for the enormous highwall embankment meters away from its southern flank. You see it as you approach the town from the north, a vertiginous bookend 30-odd meters tall. It traces the main road’s gentle curve east and then south.
There are other mining towns that are old staging or trading posts grown into small cities. But Ravenswood’s relationship with its gold mine is more symbiotic than most. It’s one-and-a-half centuries in the making, and each time the mine changes, this beautiful little town changes with it.
The most recent transformation came in late 2020 with the opening of the Buck Reef West pit. It operates 24 hours a day just a few hundred meters from town. That explains the enormous highwall, which cuts out noise and light pollution – but it also explains a brand-new Epiroc blast drill working beyond the wall, developed specially for this very site.
Mining has existed in Ravenswood since prospectors first gathered in the area in 1868 to pan and sluice for alluvial gold. These days, it’s an enormous open-pit operation run by Ravenswood Gold with the aim of producing more than 200,000 ounces of gold a year. But mining at such scale this close to a living town comes with strict environmental constraints. When longtime Epiroc customer Roc-Drill tendered for the drilling contact at Buck Reef West, it needed to commit to keeping within strict noise requirements.
“What separates this from other gold mines is the environmental impacts we’re faced with, particularly with the town being so close by,” says Roc-Drill Managing Director Nigel Deveth. “Hence, the KPIs around noise restraints and what [Ravenswood Gold] had to do to meet their license to mine.”
The challenge had two dimensions. Roc-Drill not only needed to source blast drills that could meet the noise constraints, but it needed to find enough of them to hit its contractual meterage requirements in the face of a global supply chain constricted by the pandemic. Deveth and his team immediately diverted three New Zealand-bound Epiroc SmartROC T40 rigs fitted with noise reduction kits to start work in the new pit. The kits would help cut the noise of drilling and rod changes by a game-changing 10 decibels. But going forward, Roc-Drill needed a higher capacity drill with the same noise suppression capabilities.
“We knew we could start the contract with the T40,” Deveth says. “But it wasn’t the drill of choice in regards to size. I wanted to go to a bigger drill. I wanted to keep the hydraulic drifters the same, but I wanted more air and bigger dust collectors.”
It was Deveth himself who eventually approached Epiroc – a company he has a 35-year-relationship with – to propose a solution.
“I said, ‘Why can’t we put the front end of a T40 onto the back end of the T45?’” Deveth says. “They said, ‘There is no reason, that’s an excellent idea. Let’s do it.’”
Account Manager for Eastern Australia David Green liaised with Roc-Drill while Business Line Manager for the Australian Surface Division Craig Marsh worked with Epiroc’s Product Company in Örebro, Sweden, to develop a solution that took the boom assembly and noise reduction kit designed for a T40 and fitted it onto a larger SmartROC T45 carrier. The new rig would have a higher capacity, with a 250-kilowatt versus a 168-kilowatt engine, and a 223 liters-per-second versus a 153 liters-per-second compressor, but with the relatively light-weight noise reduction kit of the T40. The modified T45 would suffer no hit to drilling performance or productivity and would maintain its class-leading fuel efficiency and emissions figures, further adding to its environmental credentials.
“It makes a huge difference to noise,” says Stewart Prince, Epiroc Regional Manager for Mount Isa and Townsville. “Particularly at night, when it’s still. That’s when you can tell the difference from a rig that’s not noise-restricted.
“We don’t work with so many noise-reduced drills in northern Australia, because you just don’t need them. You’re in an environment where it doesn’t matter. But obviously it matters for Ravenswood. They’re mining so close to town.”
The interior of the Buck Reef West Pit stands in stark contrast to the pubs and cottages just meters away across the embankment. In a matter of months, Ravenswood Gold and its contractors, including Roc-Drill, have efficiently cleared a long, flat mining pit. A squadron of Roc-Drill’s Epiroc T40 and T45 blast drills is crawling its way across the landscape towards the south as, behind them, excavators load an endless succession of dump trucks from a recently blasted section of the pit. Watching all this activity, you suspect Ravenswood Gold’s ambitions for the mine are in good hands.
Operator Craig Saxby takes some time out from working the pit to demonstrate the capabilities of his silenced SmartROC T45. The noise reduction kit is a surprisingly simple kit – a vertical series of hydraulically operated hatches that encase the mast assembly.
“You definitely notice the difference, particularly once you shut the door,” Saxby says. “You pretty much can’t hear a thing. The cabs are really good already, but the noise cancelling makes it that much more comfortable.”
Saxby’s not kidding. The difference between his silenced rig and a nearby stock T45 is remarkable. You could conceivably stand next to the cabin and not even need earplugs, it’s that quiet. Saxby explains that maintenance is also relatively easy; the operator of a noise-reduced rig simply turns the boom assembly horizontal and opens the kit’s doors for easy access. The aluminum hatches come with other advantages, such as limiting the environmental impact in the event of a consumables spill.
“These Epiroc rigs are very easy to operate and ergonomically friendly,” Saxby says. “All the controls are right at your fingertips … The [noise-silenced] T45 is a great rig. It hits hard and punches a hole down fast.”
Roc-drill plans to eventually have 11 noise reduction kit-equipped drills on site, which Deveth reckons will be the largest fleet of silenced drills in the world.
“To work with a fleet of silenced rigs, it’s been challenging,” says Roc-Drill Project Manager Corey Poulson. “There’s a lot of external parts. But they’ve run well, availability’s been great, and with the support we get through Epiroc, we’ve been able to keep the rigs running a good 90+ percent of the time.”
But Ravenswood Gold and its contractors’ care for the surrounding town doesn’t begin and end with hitting a bunch of environmental KPIs.
“That’s really important, but then there’s the engagement with the community,” says Ravenswood Gold Mining Manager David Plowman. “We’re guests here. Roc-Drill has been really good in that regard, helping us raise funds for the school raffle, along with other projects.”
It makes sense. Deveth’s personal history with Ravenswood dates back to 1983, when his father was a manager for North Queensland Gold, which mined mullock heaps left over from an earlier era of underground prospecting. Winning the contract to blast drill in Buck Reef West was a case of coming full circle.
“Community, for us, is very important,” Deveth says. “It’s about giving jobs to local people or helping them up-skill, and there’s a lot of school engagement. We have a box at the rugby stadium and raffle tickets … If you’re going to be in this community, you need to give back to this community. It’s just the socially right thing to do.”
“Companies like Roc-Drill are willing to support the community and the school, whether that’s with raffles, or building billykarts for a recent billykart derby,” says Parents and Citizens member Bianca Byers, a longtime Ravenswood local. “You’re never short on support and helpers. That could be everything from helping with weed management through to coming along to our events.”
“We can be that central point that connects off to, say, the community garden organization or the historical society, so it’s really exciting when Roc-Drill and other companies want to get onboard and strengthen that community.”