Volvo create innovative solution for Golden Equipment

Navajo opencast coal mine in New Mexico, which has an annual production rates of more than 8.5 million tonnes recently commissioned Volvo Construction Equipment dealers, Golden Equipment Co., to construct a custom-made drill truck to meet their coal drilling requirements.

Golden Equipment called on Volvo’s in-house experts to help with providing the parts and assemblies to create a solution that would fix Navajo’s problem of getting drills on top of a coal seam, setting them up quickly and being able to move them around the seam efficiently. The end result is a truck that is more mobile and much faster than a crawler drill.

This is the second time the company has created a machine of this type for the customer. Lisa Guinn, marketing manager at Golden Equipment, commented: ‘In 1994 we custom-fabricated a machine like this for the Navajo mine and it performed so well that we were contracted to build a new one.’

That truck, which is still in service, and the latest version share the same general design elements - an extended Volvo articulated hauler frame, with power pack/drilling components from a rotary drill rig. The new truck was delivered to the mine in late June for a month’s testing and breaking in before being put into production.

The new version comprises a Volvo A25E 6x6 articulated hauler chassis, stretched at Volvo Construction Equipment’s factory in Sweden to include a 5ft longer-than-standard wheelbase, along with a 5ft extension to the after-frame. Volvo also installed a cab large enough to include a reversible operator’s seat with dual controls mounted front and back, allowing the operator to control the drill from inside the cab and to drive the truck while facing in either direction.

The drilling power pack is from an Atlas Copco DML rotary drill rig, and the twin mast assemblies are Atlas Copco units normally used for water-well drilling. This set-up allows the Navajo mine to drill two 5.5in-diameter blast holes at a time, 23ft deep and spaced roughly 20ft apart. The whole drilling process takes just 45s once the drill is in position and the overall speed of the process allows the mine to drill about 850 coal blast holes per shift. The extended truck frame and cab are factory options that allow the majority of the truck’s systems such as engine, drive train and suspension to remain completely stock-standard.

Golden Equipment fabricated the platform on which the drill equipment is mounted and all of the various accessory brackets and other components needed to complete the installation. Safety features such as walkways, equipment cover latches and other items were installed in accordance with the mine’s requirements. The truck will be equipped, by the mine, with a Leica Geosystems GPS location system to provide accurate drill hole placement.