A down-the-hole drill, usually called DTH Drilling Rig, is basically a mini jackhammer screwed on the bottom of a drill string. The speedy hammer activity breaks hard stone into little flakes and dust and can be dismissed evident by the air exhaust in the DTH hammer.
[pdf] Electric generators powered by large diesel engines (the prime movers) generate electricity that move the heavy rig equipment such as the rotary table (or top drive), mud pumps and drawworks. Electric drill rigs are more expensive than mechanical rigs, but offer some nice advantages in return.
[pdf] 
The new breed of D-T-H crawler drill for pre-splitting and production drilling. Hole diameters 110-165 mm (45/16" – 61/2") Atlas Copco’s new ROC L8 is a high production down-the-hole crawler with ample power to de-liver high penetration rates and deep holes..
The new breed of D-T-H crawler drill for pre-splitting and production drilling. Hole diameters 110-165 mm (45/16" – 61/2") Atlas Copco’s new ROC L8 is a high production down-the-hole crawler with ample power to de-liver high penetration rates and deep holes..
risation and quarrying. th cab mounted monitor. May also be used for monitoring DVD • Ar .
This new version of the proven ROC L series of down-the-hole crawler drills offers extended performance through increased operating pressure and a new genius cylinder feed system. Like the well proven ROC L8 it’s well suited for large-scale production work, pre-split operations, RC-in pit grade. .
2012 year model. ENQUIRY! Discover the Atlas Copco L8 surface drill rig, designed for high-efficiency drilling in demanding applications. .
The new breed of D-T-H crawler drill for pre-splitting and production drilling. Hole diameters 110-165 mm (45/16" – 61/2") Atlas Copco’s new ROC L8 is a high production down-the-hole crawler with ample power to de-liver high penetration rates and deep holes. It has a rod handling capacity for hole.
[pdf] 
