drive

A drive is a horizontal passage excavated through rock or coal seams, typically to provide access to mineral deposits or to advance the working face of an underground mine. Unlike a shaft, which descends vertically, a drive runs roughly level and may extend hundreds of meters into the surrounding geology. It serves as both a main artery for movement and ventilation, and as a work area where extraction proceeds.

In coal mining, drives are cut parallel to the coal seam at a slight incline, usually 1 in 20 to 1 in 30, to allow water drainage. In hard rock mining, they follow the ore body or run as primary development headings perpendicular to it. The cross-section is typically 3 to 4 meters high and 3 to 5 meters wide, sized to accommodate the largest equipment that must pass through: locomotives, ore trucks, or roof support structures. The walls and roof are scaled, and temporary support installed as the drive advances.

Driving is labor-intensive and sets the pace for mine development. A single-shift operation might advance 5 to 15 meters per day depending on rock hardness, equipment, and crew competence. The process involves drilling holes in a pattern across the face, loading with explosives, blasting, mucking out broken rock, and installing roof bolts or timber supports before drilling the next round. Poor driving technique creates instability that compounds downstream, causing falls of ground and production delays.

Variants and terminology

A main drive carries the primary haulage route and is driven to high standard. A secondary drive or crosscut connects main drives or branches toward specific ore zones. A sub-level drive is a smaller passage driven at regular intervals down the length of a stope to allow ore loading and support installation. The verb to drive is also used for shaft sinking and raising, though shafts themselves are vertical. In coal mines, miners refer to driving headings or driving the seam; in metalliferous mines, the distinction between development drives and production stoping is fundamental to planning and cost allocation.

Ground conditions determine driving difficulty. Weak or shattered rock, water ingress, and soft interbeds require heavier support and slower advance. Drives in competent granite or sandstone progress faster and with less support. Geological mapping ahead of the working face, using exploration holes and visual assessment, informs support design and helps avoid unplanned encounters with faults, water, or ore boundaries that force changes to planned geometry.