Drilling efficiency

The latest developments in drilling rigs can help boost efficiency in quarry producion applications - Mike Woof reports

Efficient drilling and blasting operations can have a huge impact on production costs in quarrying. Accuracy of hole direction and depth, as well as optimum blast design and explosives use, are critical for efficient blasting work. Ineffective blasting can result in high quantities of fines of low commercial value as well as over-sized material requiring secondary breaking. This impacts on production costs and is a major factor in the difference between operations that are profitable and those that are not. Poorly designed and controlled blasts can also increase noise levels and safety risks from flyrock. Inefficient blasting also results in uneven quarry floors that reduce working efficiency at the face and increase wear and tear on loading and hauling equipment.

The major rig manufacturers are investing heavily in redesigning and revamping their machines to meet demands from customers. These new and more sophisticated machines can use advanced software tools that help the user to plan blasting operations accurately and ensure that the cost/tonne is reduced. However firms have also realised that not all customers require the most sophisticated drilling systems and have developed modern machines using simple hydraulic controls. Firms have also continued to fine-tune the various technologies, with down-the-hole (DTH) and tophammer machines both offering a much broader range of capabilities than before. New drillstring technologies allow hydraulic tophammer rigs to drill deeper and with more accuracy while the latest DTH machines are more efficient than in the past.

161 Atlas Copco has made significant investment in its surface drilling line, with an array of new models aimed at use in quarrying applications. These blasthole drills span a range of sizes and drilling methods, to suit differing needs with regard to hole depth, productivity and size of operation. The machines suit a range of requirements, for customers running highly computerised operations through to the needs of users with more basic operations.

The new SmartROC T40 rig is said to offer considerable savings in operating and running costs, due to its sophisticated drilling control systems. The rig is also said to be easier and cheaper to service, as well as being comparatively easy to use. Atlas Copco claims that the T40 is the most fuel efficient rig in its class, as well as being the easiest machine of this size to use. The machine benefits from a newly designed user interface. This allows operations to be performed by using the two main joysticks and its single screen and these improvements ensure that the machine is easy to use, even by a non-skilled driller.

Power comes from a new Tier 4 Interim/Stage IIIB emissions compliant diesel, which is also said to feature reduced fuel consumption. The overall efficiency of the rig with its new engine means that it can deliver fuel savings of as much as 50%, depending on rock conditions according to Atlas Copco. The design of the new SmartROC has also reduced the number of hoses by 50%, couplings by 70% and hydraulic oil by 65%, reducing maintenance costs. Productivity, loadability and fragmentation are all said to be improved, due to the sophisticated drilling control system. The machine is equipped with Atlas Copco's new PC ROC Manager software, which allows documentation of the drill and blast operation.

The SmartROC T40 can be used to drill hole diameters ranging from 76-127mm. Field tests show that decreasing the hole size by 12mm reduces the fuel consumption by 15%. For contractors, versatility is a major benefit, allowing firms to bid for cutting jobs using 76mm blastholes as well as quarry work with 127mm diameter applications using the same rig. The machine is available with an optional radio-remote-control function to increase operator safety and also allow a wider application coverage. The COP 2560 rockdrill is also said to provide on average 10% higher impact energy efficiency than other rig types on the market. Customers wanting to optimise productivity can also opt for a CARE service agreement, which is said to ensure efficient machine performance.

Atlas Copco is also upgrading its proven ROC F9C tophammer rig, which benefits from the firm's SmartRig package. Features include ROC manager for planning and control, hole navigation system (HNS), automatic feed alignment, automatic rod adding system, and rock drill control system. The ROC manager function is used to design drill patterns and analyse results and running on a standard PC, this can be used to consolidate data about multiple rigs at multiple sites. The hole navigation system monitors and controls drilling functions, providing a record of hole alignment, burden and spacing. The high precision navigation system optimises drilling and blasting, improving fragmentation and decreasing the quantities of explosives needed. The SmartRig's automatic feed alignment reduces set-up time by setting the feed to predefined angles. The Atlas Copco SmartRig ROC F9C drills holes between 89-127mm in diameter and the machine is powered by a diesel rated at 224kW, while its rockdrill power output is 25kW.

The new PowerROC series of surface crawler drill rigs has been developed from Atlas Copco's former CM line and includes the PowerROC T25, T30 and T35 tophammer rigs. The PowerROC models feature the COP logic drilling control system, which adjusts drilling parameters in real-time and helps with drillhole straightness. Meanwhile continuous feeding keeps the bit in contact with the rock and helps to optimise transfer of impact power. In addition, continuous adjustment of feed and impact pressure reduce energy use, cutting fuel consumption. Additional savings to running costs are said to be provided by the hydraulic cylinder feed, which has a rigid aluminum feed beam with precise feed force for longer drill steel life.


Furukawa Rockdrill is aiming its new high performance DTH rig squarely at the US market. The rig has been designed for North American customers and can drill hole diameters from 87-up to 127mm. The new DCR20 features a high output compressor delivering 24m3/min and this is said to give increased flushing air. Removing the cuttings from the hole efficiently increases the penetration rate, cuts regrinding of loose material and also reduces wear and tear on the drill bit. The DCR20 rig is powered by an emissions compliant 2294 CAT C3 diesel rated at 328kW. To boost productivity the machine features a drill pipe changer, equipped with electronic sensors to speed up changes.

Rockmore International continues to develop its DTH range with the addition of the new ROK 500 and 500Q variants. These new patented 127mm diameter class hammers are designed to increase drilling efficiency. The new models are designed for two different air packages, to match different working conditions. The ROK 500 is rated for use with large compressors while the ROK 500Q hammer is designed for smaller compressors. As with all of Rockmore's DTH hammers, the 500 and 500Q feature Rockmore's patented SonicFlow technology, which optimises airflow by streamlining the air path to minimise backflow and turbulence so that more energy is delivered to the piston. This increases both the efficiency and the penetration rate.

Meanwhile 325 Sandvik continues to develop its blasthole rig range, with the introduction of its new generation DTH machines. The new DI550 is said to offer high productivity and user comfort and suits duties 127mm diameter and larger blasthole drilling applications. The machine is aimed at use in large and medium sized quarries and also with contractors. The new DI550 features include a 324kW diesel and a 24.4m3 compressor air flow at 24 bar pressure, making the machine a good match for a 127mm diameter DTH hammer. This match of power and hammer size is said to make the rig productive, whilst keeping fuel consumption and operating costs as low as possible. Cost effective performance is further improved by features such as optimised diesel RPM level during drilling and active control of compressor running temperature.

The machine features a sophisticated control system with comprehensive service information as well as an over-pressurised ROPS and FOPS certified cab with good visibility of the working area. The efficient dust collector offers non-stop cleaning and improves filter lifetime. The new DTH line has benefited from Sandvik's experience in top hammer drilling solutions. The DI550 is suited to work at its maximum performance with Sandvik's RH550 hammers from 76-127mm. The RH550 hammers come with bits from 90-152mm with three different bit face designs.