Atlas Copco's new Rocket Boomer drilling rigs for mining and tunnel construction feature the latest in computer technology that should mean more accurate drilling operations.
This is an important year in Swedish plant manufacturer Atlas Copco's history. Not only is it the company's 125th birthday, but it has now completely restructured its rock drilling operations, centralising them in rebro, west of Stockholm.
From now on, all production, research and development and marketing for this side of the business will be carried out here, rather than spread throughout the world. Company president Kjell Carlsson explains that the restructuring makes production more efficient. 'Throughput time from customer order to delivery is down to eight weeks - 50% faster than it was.'
Coinciding with this move is the launch of two new Rocket Boomer drilling rigs featuring a computer based drilling system that controls tunnel face drilling to improve accuracy and efficiency.
The machines, the L2C and M2C, are the result of five years' intensive research and development. The M2C is a medium size, two boom face rig designed for stoping and drifting up to 45m2 face area for the mining industry. It replaces the company's Rocket Boomer 322. The L2C is larger and is designed primarily for drifting and tunnelling for constructing tunnels up to 90m2 in cross section. It replaces the Rocket Boomer 352.
The rigs are built to a new modular design and will be produced in the company's new streamlined factory. They are assembled from five basic modules: the rear module, engine module, power pack module, boom frame module and the booms themselves. It is this, along with the use of many shared components, that helps slash production time by half and allows easier servicing and assembly and disassembly of the machines for transporting down access shafts.
The rig modules are linked by a single cable to form a digital network similar to one that links PCs in an office. The master module in the cab communicates with each module, controlling and monitoring all their functions and also running diagnostic programs to detect any faults. Atlas claims the set up of the electronic systems is robust and is able to withstand the tough environmental conditions that the rigs will have to work in.
The computer system has been developed closely with CC Systems, a company that has experience in developing local networking systems for this type of environment. It features the Contour Control System, which manages the drilling operations when the machine is at the tunnel face.
Before work starts, the drilling pattern is downloaded onto a small PCMCIA card (with 6Mb memory), along with other information including preferred drilling parameters. This is simply slotted into the rig's on- board computer, ready for work to start. All information, including the drilling pattern and the fault location diagnostics, is displayed on the operator's control panel.
Once at the face, the rig works out its exact position using laser surveying and total stations. Then, after it has located the booms - each boom is fitted with nine sensors - in three-dimensional space, drilling can be carried out to the predetermined pattern. The PCMCIA card also stores drilling records and the geology encountered during drilling.
Atlas claims that by removing the need for manual guidance (previously an engineer would paint the location of the drilling points on the face) the quality and accuracy of the drilling is improved which in turn leads to a reduction in overbreak.
Field trials of the new machines have shown the benefits of the new systems, says Atlas. The first L2C was used by Norwegian contractor Selmer for six months and Ammerberg Mining has tried out the first M2C at Zinkgruven mine in Sweden over 21 months. Both showed an improvement in drilling performance and accuracy, it says.
The next step will be fully remote controlled operations, with radio links rather than memory cards used to pass information from the design office to the tunnel face. And Atlas can now produce what it calls 'virtual prototypes' at rebro, with a sophisticated computer design system that will allow new machines to be 'built' and viewed on screen, effectively removing the first stage of conventional product development.