Pit Viper 311 wide-range rotary blasthole drill can surface drill holes to 125 feet in a narrow range of sizes 9 to 12.25 inches, which fills the gap between the hole ranges of the Pit Viper 351 and the Pit Viper 270. Drive train options include both Tier 4 and Tier 2 engine choices. The tower has an interchangeable unit and accommodates large sheaves for either single-pass or multi-pass applications. Bits can be changed above the Pit Viper 311 rig’s deck even while single-pass drilling 65-foot-deep holes. The two-speed hydraulic rotary head delivers 12,880 lb.-ft. of rotation torque at 140 rpm and 7,000 at 240 rpm. A new cab has a fully adjustable chair with joystick and cab controls, and has been elevated above the deck to give the operator a better view.