Cover story: Atlas Quarries' Rokbak RA40

By: Cameron Officer, Photography by: Cameron Officer

Porter Equipment recently delivered two Rokbak ADTs to Atlas Quarries’ Brynderwyn quarry in Northland

Atlas Concrete, Atlas Quarries, and Atlas Recycling have been running multiple machines supplied by Porter Equipment for many years now.

In the Auckland and Northland regions across sites in Albany, Wairau Road, Helensville (Mt Rex), Brynderwyn, and beyond, Porter-supplied machinery has been a feature of this multifaceted company’s broader fleet for nearly three decades.

The 40T Rokbak RA40 is the larger of two models of ADT Rokbak manufactures

The last time I caught up with Brynderwyn quarry manager, Tony Turnbull, it was to check out the company’s then-new Sandvik QJ341 mobile jaw crusher (see Deals on Wheels issue 339). This time, we were back at the busy Brynderwyn quarry to have a look at twin Rokbak RA40 articulated dump trucks, which have just joined the fleet.

Despite all this heavy metal though, Atlas Quarries in partnership with McKenzie Contracting have been engaged in a much more intricate part of quarry development lately – one that involves local wildlife.

"We have consent to expand the quarry, ensuring it will be active for a long time to come," says Tony.

"Before we create a new overburden area, as part of our obligations we need to conduct a species management programme. This means we need to locate and remove native snails, bats, and lizards, if discovered, and relocate them to a safe habitat. We have kiwi dogs that have come in as well. It’s actually fantastic for the local environment and Atlas is proud to be involved in this."

Good things come in twos, including heaped load capacity of 23m3

While creepy crawlies have been occupying time in the lead-up to the next phase of the Brynderwyn quarry’s development, once Tony’s team gets the all-clear they’ll be into the real action, with the two new articulated haulers needing to prove their worth as part of the wider quarry machine fleet.

Tony says that, despite the sure-footed abilities of the articulated haulers, there is and will always be a place in the quarry for rigid dump trucks too.

"If you just need to cart aggregate on the benches, then you can’t beat a rigid dumper. They are fit-for-purpose and there aren’t many things that can go wrong with them," he says.

From left: Atlas drivers Adrian Clyde, Sudesh Thuiyadura, Atlas quarry manager Tony Turnbull, Selwyn Tilly of Porter Equipment, and Atlas quarry operator Jordan Potini

Testament to that is the continued use by Atlas Quarries of a pair of battle-scarred Terex TR35s that will remain in service at Brynderwyn for a while yet.

"The thing with the ADTs is that they give you more flexibility, but as a business, you need to be aware that there’s more technical complexity in those machines. That’s where choosing a solid brand and a solid distributor is important."

Building on the storied foundations of the now-superseded Terex name, Rokbak articulated dump trucks are still built tough in Scotland and shipped to some of the world’s most extreme environments. Designed with decades – not just years – of service in mind for the owner, the 40-tonne Rokbak RA40 articulated hauler (the manufacturer also builds a 30-tonne Rokbak RA30) is purpose-built to offer consistent performance in a fuss-free manner.

Not only is the body engineering designed to stand up to daily work punishment, but at the centre of operations, the truck cab is roomy and comfortable across all surfaces and offers excellent outward vision for Atlas Quarries drivers Adrian Clyde and Sudesh Thuiyadura.

The 6x6 haulers are powered by a 331kW (444hp) turbo-charged Scania straight six paired with an Allison HD4560 fully automatic six-speed transmission. Making good use of maximum available torque of 2255Nm (available from 1300rpm), the Rokbak RA40’s three heavy-duty axles in permanent all-wheel drive feature differential couplings between each axle to prevent driveline wind-up.

The hauler boasts automatic limited slip differentials in each axle, while the leading rear axle incorporates a through-drive differential to transmit drive to the rearmost axle. This differential and the ADT’s dropbox output differential are locked simultaneously using one switch selected by the operator in the cab. The end result is a driveline that’s designed to maintain mountain goat traction and consistent speed on the toughest haul roads.

Tony says that on the steeper, softer sections of the quarry being developed up at the perimeter as part of the stripping project, Atlas’ ADT operators need engine braking that they can rely on.

Porter Equipment supplies tough Rokbak articulated dump trucks throughout NZ

"Where we’ll be hauling to and filling out once the weather clears up is pretty steep, so with a full load onboard you need to know the truck is going to stop where you want it to. It’s one thing to scramble up a hill without any worries, but when you’re at the wheel, you also want to know the machine will remain predictable and maintain traction on the way down too."

The Rokbak RA40s feature a modulating transmission retarder coupled with an efficient exhaust brake and fully enclosed oil-cooled multidisc brakes. This results in braking performance Atlas Quarries personnel can rely upon all day every day.

"Bang for buck is always going to be important for us, but in investing in the Rokbaks, we were also looking for a big improvement in reliability and safety," says Tony. "We’ve had extra guarding running the full length of our trucks front ends installed for added peace of mind for the operators. They have cameras onboard too, which is a necessary bit of kit these days and really useful.

"The trucks are well designed for servicing and all the main checkpoints are at ground level. Naturally, Porter Equipment will service the machines initially, and they are always easy to work in with to get that done.

"Overall, Porters makes it easy to research, trial, purchase, and maintain machinery – they are dependable right through that process – and we know the Rokbaks will perform for us as we develop the quarry through this next phase of operations."

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