Crawler Mounted Drills

Rock drills are large and powerful drilling machines. A rock drill creates a hole in the earth usually called a bore hole. At D & L Thomas Equipment we sell and service both hydraulic, air powered track drills and the drifters on them for drilling.

A Drifter is either a hydraulic or pneumatic powered rock or ground drill placed on top of a feed. The feed is like a rail that the drill travels on, aka. drifts. This kind of drilling procedure is also called drifting. The feed is usually attached with a flexible boom (like an arm) to a stationery or mobile unit that contains the powerpack (engine and hyd. pump or compressor). Drifters are used in mining, construction, and exploration.

A hydraulic rock drill or drifter is usually a machine, that consists of a percussive system and a rotative system. The percussive system strikes the drill steel, for example 2000-5000 strikes per minute as the rotation can be, for example, 100-400 rounds per minute. Combined together, these functions enable drilling holes into rock. The excess material (cuttings) is then pushed up from the bottom of the hole by means of pressurized air or water.

Hydraulic rock drills are also called hydraulic top hammers, which explains the position of the actual drilling device concerning the drill rod. Opposite to a top hammer drill or drifter is the down-the-hole hammers, which are usually pneumatic.