Switching to the SmartROC C50 tophammer drill rig has increased productivity and made drilling accuracy much easier at Glensanda – the largest granite quarry in Europe.
Epiroc SmartROC drilling analysis
In the Scottish Highlands, on a mountain rising from the banks of Loch Linnhe, is the site of the largest granite quarry in Europe – Glensanda. Located 520 meters above sea level, and a good kilometer inland to minimize visual impact from the coast, it has been in operation since 1986. The quarry produces around 7 million tons of aggregate per year, and reserves are expected to last at least until the year 2100.
The aggregate from Glensanda is transferred via conveyor through a tunnel to a second crusher by the deep-water docks on shore. The dock location provides a site where any port in the hemisphere can be reached. The Glensanda quarry is owned by Aggregate Industries, but the company sub-contracts drilling and blasting to BAM Ritchies.
"We’re nine people in the quarry, and produce about 130 000 tons per week working one shift per weekday. A few years ago we switched over to SmartROC C50 and T40 tophammer drill rigs."
Switching to modern, technically advanced rigs with a high degree of automation and GPS capabilities has made a world of difference.
"Take the C50, for example – it’s far more efficient than the old L7 we used to have. We’re saving 47 percent on the fuel compared to the former rigs, and Epiroc have increased the service life of the hammer by 50 percent. It’s easier to adjust the airflow, which saves the drill bits. It’s measurably increased the lifespan of the consumables. The C50 has achieved a 40 percent increase to the lifespan of the outer steels and reaches around 20 000 meters, and a nearly four-fold increase to 90 000 meters for the inner steels."
SmartROC C50 hole navigation system and cab screens
Gary Stewart agrees. He is an operator of the SmartROC for BAM Ritchies at Glensanda and has found that the comfort, noise reduction and ease of operation with just two controls that operate all the drilling for most of the functions works extremely well.
The drill plan for the drill and blast operations at Glensanda is created by scanning the rockface, marking the planned holes, then saving the data to a memory stick which is plugged in and uploaded to the SmartROC rig. The rig then drills the holes at correct angles, azimuths and depths, and saves all drill data so it can be used when planning the charges for the blast.
"The C50 is far better on the fuel and on the drill steels, and it’s a lot comfier. It’s a nice environment in the cabin, which is good since I spend the majority of the work day inside it. The RCS4 screen is a lot bigger and easier to use and gives you much more information. I can control more from the cab rather than walk round trying to find problems.
I start the top of the hole manually. When I’m satisfied it’s going well, the automatic drill control will drill the rest of the hole. When for some reason or another we can’t drill at the marked location, the machine will calculate a new angle, azimuth and depth. The bottom of the hole will be in the proper position, even if the top is a couple of meters to the side."
"The rig collects a lot of data about for example rock quality when drilling. This is a huge benefit to us when we plan future blasts."
The GPS functionality has made a great difference to the efficiency of the shots. Not having to manually estimate where to drill or make corrections has helped BAM Ritchies to maximize the burdens and spacings on shots, increasing production. The GPS is particularly helpful at a site like Glensanda.
"Well, we’re high up on a mountain above the sea. About 30 to 40 percent of the time we have really bad mists with a sight of 3–4 meters. Previously, we lost a lot more time due to the weather conditions and surveying but now we can do everything from the cab without putting the operator at risk. In the winter there’s lots of snow, and this is when the GPS really comes into its own by letting us drill at the proper location right through the snow cover. That has made a huge difference in productivity."