Load & Haul

Surface driller goes back to basics

Atlas Copco has launched the PowerROC series of tophammer surface crawler drill rigs in Australia as part of the global overhaul of its overall product range. Karreman Quarries in Cleveland, on the outskirts of Brisbane, was host to the Australian launch of the T35 earlier this year and the first of these machines has since been employed by Donnelly Blasting Services at Mount Marrow, near Ipswich (see pages 32 and 33). Units have also been operating in Papua New Guinea and New Caledonia.
The PowerROC ?family? are hydraulic drill rigs whose focus is on delivering performance and accessibility with a straightforward design and minimal maintenance requirements. The PowerROC rigs also potentially offer a lower running cost per engine hour and are primarily designed for use by contractors in a number of applications, including aggregate and limestone quarries and civil construction projects. Atlas Copco describes them as low tech, but ?high quality? units.
There are three PowerROC units available: the T25, T30 and T35. They replace the ECM 585 surface crawler but have the modular look and feel of Atlas Copco?s other newly revamped ROC series of pneumatic and manually operated drill rigs (the AirROC series) and high technology rigs (the SmartROC and FlexiROC series).
Although the PowerROC units are manual vehicles, they utilise the COP logic drilling control system to adjust drilling parameters in real time and help the operator continue drilling straight holes. Continuous feeding by use of cylinder and rope results in the bit maintaining constant contact with the rock and helps to optimise transfer of the impact power.
In addition, the ongoing adjustment of feed and impact pressure reduces excessive energy use, thereby reducing fuel consumption. The hydraulic cylinder feed system, which employs a rigid aluminum feed beam with precise feed force for longer drill steel life, provides more operational savings.
The PowerROC T25, T30 and T35 address hole quality through the optional 3D hole inclination instrument in the operator?s cabin. This device controls hole depth and contributes to accurate alignment control while collaring. The PowerROC rigs use COP 1240, 1640 or 1840 rock drills (ranging from 12kW to 18kW) to deliver 51 to 102mm (two-inch to 4.5-inch) hole diameters at a maximum hole depth of 21m (69 feet) to 25m (82 feet). They are powered by Tier 3 Cummins QSB 4.5 or QSB 6.7 diesel engines and feature single and/or extendable booms on track frames with triple grouser pads and hydraulic track oscillation and three-speed traction (comprising either the Komatsu D20-6 with a single boom or the Komatsu D20-7 with extendable boom). The rig?s other options include a water mist system that enables it to stabilise hole walls when drilling in rock formation. A 150-litre pressurised water tank is connected directly to the flushing air compressor.
George Stirling, Atlas Copco?s regional business manager for Australia and Africa, stated that in performance tests in Europe and Japan with the old ECM 585 and a rival Furukawa 1200, the PowerROC T35 had demonstrated ?a 15 to 20 per cent increase of net penetration rate with a leaner fuel burn?. However, Atlas Copco is insistent that the engine power of the PowerROC (190kW) is not sacrificed for fuel economy (the PowerROC has a 100 litre fuel-injected engine).
?It is one of the lowest per ratings for the engine, so there?s room if required to increase the horsepower,? George explained. ?We?re working with the correct loading on the pumps and the correct loading on the compressor, which means we can run at a lower horsepower compared to composition, which means less fuel burn. And we have more than sufficient tyre reserves at the ratio we?re at today, so there?s scope for adjustment.? He added that the low rating is consistent with Atlas Copco?s aim to create an economical, high quality performing rig that is also very low on maintenance. ?It?s always been our philosophy where we had the right size of rig for the hole, there is no point of having a 20-tonne rig on the ground to drill a 90mm hole. And the same flows through to the engines, compressors, everything has to be, by the Swedish way, ?just right?.
?The performance comes through simplicity and reliability,? George added. ?We?ve kept the electronics and the sensors to an absolute minimum, which means the operator is more or less self-sufficient.  So if he has a breakdown, he is generally more than capable of repairing it, otherwise you?re looking at two or three days to get a technician in. The T35?s predecessor, the 585, was a class leader, in terms of simplicity and performance reliability, so our focus was to keep the new model in a similar vein.?
{{image3}}George Stirling also remarked that the operator friendliness and simplicity of the PowerROC made it an attractive prospect for contractors who take the machines on different jobs throughout the country and for personnel in smaller quarries who will operate different types of equipment, from loaders to dump trucks to excavators and may be required to relieve the driller.
?Speaking to the drillers [at the Karreman Quarries launch] who?ve been in the T35, they?ve just jumped in the cabin and they feel right at home. So for many operators, there?s no need for retraining, it?s just a natural progression and they can just follow environmental constraints. There is no disadvantage for any plant and equipment operator who is not a driller to operate this machine. They?ll sit in the chair and they?ll feel comfortable very quickly. I reckon they?ll become drillers very quickly as well.
?For this specific market, it?s a manual, hands on driller?s machine. The driller pushes the lever, it goes down, he pulls the lever back, it goes up.? George Stirling said the feedback of European and Japanese customers about the PowerROC family had been very positive and that he thought the PowerROC series had ?exceeded? customer expectations.
?All our machines punch way above the weight category and that?s been a pleasant surprise for those customers. We?ve taken a product that was a market leader ? the 585 – and we?ve improved upon it, which is reassuring.?
Damian Christie attended Atlas Copco?s official Australian launch of the T35 surface drill rig at Karreman Quarries, Cleveland in February 2011.

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