Leicester-based TI Drilling & Blasting Services is reporting a 40 percent reduction in fuel consumption and a 20 percent increase in drilling productivity following the purchase of a new Sandvik DI550 down-the-hole drill. The 24-tonne unit is spearheading production at the Old Cliffe Hill Quarry that was recently reopened to access the site’s extensive reserves of South Charnwood Diorite. 
The estimated 80 million tonnes of rock reserves that lie beneath the Old Cliffe Hill Quarry and the neighbouring “New” Cliffe Hill Quarry are thought to be among the oldest in the UK, having been laid down more than 600 million years ago. Indeed, the faces at the old quarry site provide a detailed “slice” through geological time from the Precambrian age to the present day. The South Charnwood Diorite (previously known as Markfieldite after the nearby village of Markfield) forms part of the Bradgate Formation and is a hard, igneous rock that is highly prized in a variety of construction and road-building applications as far afield as London to the south.
Both the old and the neighbouring new quarry – which are adjoined by the 720 metre long Joskin Tunnel – are operated by Midland Quarry Products, one of the UK’s largest producers of hard rock and asphalt products. Drilling duties are charged to TI Drilling & Blasting services – acting as sub contractor to Blasting Services - whose connection to the twin quarry site dates back to 1986. When the old quarry was closed in 1989, TI Drilling focused its attention on the neighbouring Stud Farm Quarry site. But with the reopening of the Old Cliffe Hill Quarry, the company renewed its acquaintance with the old site, starting work again in 2007.
TI Drilling founder Terry Inskip says that blasting takes place at the old quarry site approximately three times per week (as opposed to the daily blasts employed during his initial deployment at the site) with each blast dropping between 30,000 and 40,000 tonnes of rock. 
Inskip reports that his bold decision to purchase the first DI550 crawler mounted DTH drill rig in the UK was prompted by a desire to reduce fuel costs. “As a contractor, I keep a close watch on the cost of fuel. But not as close as the quarry operators that ultimately pay for the fuel,” he explains. “With the rising cost of diesel, we were conscious of the need to reduce fuel consumption. And after a visit to the Sandvik factory in Finland last year (2010), we were convinced that the new DI550 rig could help us achieve that.”
Even though this was a key factor in his purchasing decision process, even Inskip says that the fuel consumption reduction has come as a pleasant surprise. “Compared to our existing, competitive rigs, we have seen a 40 percent reduction in fuel consumption with the Sandvik machine,” he asserts. “With diesel fuel price rising on a monthly basis this is proving to be a significant cost saving.”
That reduction is afforded to a large degree by the use of a clean-running Tier 3 Caterpillar C13 diesel engine that delivers 328 kW at 1,800 rpm, and by a variety of advanced controls including automatic flow and pressure control and engine RPM optimisation during different phases of operation.
But Inskip is keen to point out that those impressive savings have not been achieved at the cost of productivity. Combined with a 24.4 m3 capacity at 24 bar compressor pressure and a 5” hammer, the Sandvik DI550 is uniquely productive. “The rig is incredibly fact. Even the twin-speed tracking has been a bonus, allowing us to move from face to face quickly,” Inskip adds. “Based on the first two months of operation, it is already around 20 percent faster and more productive than our older rigs.”
And that speed is not confined to the rig’s drilling capabilities, according to Inskip. He reports that daily servicing and maintenance duties are also easier and faster, thanks to a redesign that ensures that all key maintenance points can be readily accessed from ground level. “Maintenance duties that would have taken hours previously can now be accomplished in minutes,” Inskip insists. “And even large-scale maintenance operations do not keep the machine out of action for more than an hour or two.”
However, TI Drilling & Blasting will not be spending too much time “under the hood” of its new machine in the near future, thanks to the sophisticated design of the machine and excellent field support from Sandvik. “We bought the machine with the Sandvik Security+ warranty that covers the machine for three years or 5,000 hours and a four year, 8,000 hour warranty on the engine,” he says. “But with the hours that we’re working, this is absolutely vital as we need a service every month.” 
Inskip further highlights the Sandvik DI550 unit’s suitability for the Old Cliffe Hill Quarry site which features an almost constantly shifting geology. “All drill rigs love constant hard rock drilling, but when they hit a bed of clay, the material has a tendency to clog the tool,” he explains. “The DI550 rig has an anti-jamming system that senses softer material and automatically pulls the tool back.”
Like any modern quarry professional, Terry Inskip is ever-mindful of the need for operator comfort and safety. But within TI Drilling & Blasting, this has taken on even greater significance as Terry’s son Jack is learning to operate the Sandvik DI550.
“Of course, we want all our operators to be safe and comfortable while they’re at work. But when it’s your own son at the levers, it is even more important,” Terry Inskip concludes. “Thanks to the Sandvik DI550, I am happy that my son is learning in one of the most advanced rigs of its kind, and that he is safe, protected and comfortable while he’s doing so.”
The Digger Blog would like to thank Mark Anthony, for the information on this Sandvik product.
