All mechanical and hydraulic systems are enhanced compared with existing models. For example, with 194 kW (260 hp) input on the multi-pass machine, the DR460 has 38% more rotary horsepower than typically seen in this size class. Tim Murphy, vice-president Surface Mining Drilling at Sandvik said: “When ground conditions allow, the operator can increase his rotation without sacrificing torque, to gain penetration rate without stalling.” The feed system has been designed with extreme hard rock in mind by including extra heavy duty chains to ensure a constant load at increased rotation speeds.

From a service and reliability perspective, the DR460 offers a full perimeter walkway for improved access. The drill has been engineered to meet stringent Australian standards (MDG15) for electric and hydraulic design. The hydraulic system has been designed to reduce the amount of hoses in one location by moving the hydraulics nearer to the point of use. In an effort to reduce fire hazards, the electrical system has been encased and isolated from the hydraulic system to keep the two from interacting.

“We have used piping to eliminate as much hose as possible and all of the piping is secured to the machine,” said Murphy. “The purpose is reliability over time. Hoses tend to chafe. Although it’s impossible to completely eliminate it, you try to minimize it where you can.” The hydraulic lines are secure through Stauff clamps, eliminating plastic zip ties.

A FOPS-rated, 4.4-m2 (47-ft2) cabin offers the operator a comfortable work environment. “The electro-hydraulic controls are mounted in the chair and the chair faces floor-to-ceiling windows providing an unobstructed view of the drill deck,” Murphy said.

A standard DR460 is engineered to operate at an ambient temperature of up to 54°C (130°F), but can also be equipped with optional cold weather equipment that includes generator sets and machinery housing for arctic climates. “In extreme cold, we use Mesabi coolers,” Murphy said. “Because of the thermal expansion capability, they handle cold oil better than an aluminum core.” For work at high elevations, an optional engine is available capable of operating at locations up to 5,000 m (16,400 ft) above sea level.

Sandvik says the main goal of the DR460 is to increase productivity while adding features to improve reliability, operator acceptance and serviceability. Maximum pulldown force is 356 kN (80,000 lb) and bit load is 445 kN (100,000 lb) for optimal productivity in hard rock formations. The DR460 is capable of drilling benches up to 75 m (246 ft) with 12.8-m (42-ft) long drill pipes. “The DR460 has a longer single-pass capability than our previous models and our competitors,” said Murphy. “Many mines are using hydraulic excavators and they prefer a 10-meter bench. With 42-foot pipe, the DR460 can drill a 12-meter clean hole on the first pipe.” The first machine is being delivered to a Canadian coal operation and Sandvik will have a model on display at MINExpo.