Keeping its newest member of the Pit Viper family top secret, Atlas Copco introduced the Pit Viper 311 wide-range rotary blasthole drill to the world at MINExpo 2012 in Las Vegas September 24 to 26. The PV-311 is designed to meet the demands of today’s expanding mining market with the proven systems, components and technology of the Pit Viper series.
The Pit Viper 311 is similar to the Pit Viper 351 with its single-pass drilling but the Pit Viper 311 has the capacity to drill holes deeper to a maximum depth of 125 ft. (38.1 m). Drilling up to 65-foot (19.8-meter) clean holes with a live tower can reduce non-drilling time and, combined with taller benches, can greatly increase production capability.
The Pit Viper 311 is the first release of the all new Pit Viper 310 series. Atlas Copco Engineering Project Manager Iain Peebles says the PV-311 offers a narrow range of hole sizes 9 to 12.25 in., which fills in the gap between the hole ranges of the Pit Viper 351 and the Pit Viper 270.
“We’ve incorporated a lot of existing technology that’s proven successful on our other Pit Viper models,” Peebles says, adding that there have been some upgrades. “One of the things we’re most excited about on the PV-310 series project is our new cab. Now you have a fully adjustable chair with joystick and cab controls. We’ve elevated the cab above the deck to give the operator a better view. We’ve tried to improve operator visibility around the machine, with larger windows and mirrors placed so the operator can see what’s going on at ground level and the front of the machine.”
The Pit Viper 311 offers drive train options with both Tier 4 and Tier 2 diesel engine alternatives. The tower has an interchangeable unit, structurally similar to the Pit Viper 351, but is deeper to accommodate larger sheaves for either single-pass or multi-pass applications. Weldments have also been improved, including a ladder that provides access to decking in the tower above the rod changer when the tower is horizontal.
Bits can be changed above the Pit Viper 311 rig’s deck even while single-pass drilling 65-foot-deep (19.8-meter-deep) holes so operators will have their eyes on making and breaking the connection each and every time.
The two-speed hydraulic rotary head delivers 12,880 ft.-lbs. (17.62 kNm) of rotation torque at 140 rpm and 7,000 ft.-lbs. at 240 rpm. Hydraulic cylinders drive the cable feed system, and the patented automatic cable tensioning system reduces cable and rotary head guide wear by continually keeping the rotary head aligned and taut, cutting down on unscheduled maintenance time.
Standard across the Pit Viper range, including the Pit Viper 311, are a hydraulically powered breakout slide wrench and a hands-free auxiliary hydraulic wrench with a 6-inch clamp cylinder. The fork chuck features an improved deck bushing.
Atlas Copco offers a number of options for the Pit Viper 311, including a patent-pending automatic hydraulic clutch designed to decrease fuel consumption during non-drilling operations. In addition to standard safety and interlock features, the unit’s Rig Control System supports auto-level, auto-drilling, GPS hole navigation, wireless remote tramming and more.
A multi-pass version of the Pit Viper 311 known as the Pit Viper 316 is now under development. The Pit Viper 316 will drill to a depth of 295 ft. (90 m) using a five-rod carousel with 50-foot drill pipe. The Pit Viper 316 is scheduled to be launched during 2013 as a replacement to the DM-M3 model and will specifically match the flexibility required for cast-blasting operations in coal mining.