Engine hours are beyond the industry’s “excellent” rating of 6000 engine hours per year with the first unit, 112 (aka Judy) achieving a record level 6876 hours in her first year and 113 (John) has come in at 7006 hours in his.

These operating hours results are unprecedented and are fully supported by Ravensworth’s maintenance summary reports, according to Caterpillar.

Caterpillar product support representative for drills Andrew Elbourn said: “What this means is the MD6420B is a low maintenance drill overall. It self-monitors and diagnoses issues, which drives low MTTR (mean time to repair). The performance of these drills has been incredible. They just keep drilling.”

With a maximum bit load force of 42,000kg and three different mast lengths to choose from, the MD6420B can drill holes as large as 311mm in diameter and as deep as 74.4m—making it ideal for high-production drilling in hard or soft rock applications.

The rotary drill features heavy-duty structures, rugged components, a comfortable cab, convenient service access and many other attributes that reduce cycle time, improve productivity and lower ownership costs.

The MD6420B has advanced controls and technology such as the control system that is ECM/CANbus, which is fully electronic with state-of-the-art user interface.

Drill monitoring and diagnostics are displayed on a large touch-screen panel. History files detailing machine performance and health are downloadable.

The control system also includes real-time machine health monitoring and built-in diagnostic tools that contribute to strategic service and maintenance planning.