collaring

In deep mining operations, a collaring is a metal or wood band, ring, or collar assembly that secures a pump to the mineshaft column at a fixed point. As water or other fluids are extracted from underground, the pump and its delivery pipe must remain stable against vibration, thermal expansion, and the weight of the column above it. The collaring clamps the pump assembly to the shaft structure, preventing drift and misalignment that would cause seal failure or uneven wear.

The design varies by pump type and shaft construction. In older mines, collaring often consists of a wooden block or iron collar bolted or welded around the pump body, with projecting lugs anchored to the shaft framework. Modern installations typically use precision-cast iron rings or fabricated steel sleeves that grip the pump body with tapered bolts or set screws. The collaring sits at or near the pump's top bearing housing, where mechanical stresses concentrate. Multiple collars may be used on long column shafts to distribute load and control lateral movement.

Placement and maintenance

Collaring is most critical on vertical or inclined mineshaft pumps, where gravity and column weight constantly pull downward on the pump assembly. Incorrect collaring can allow the pump to settle gradually, opening up packed-gland joints and admitting air into the system, which causes cavitation and efficiency loss. Conversely, over-tightening the collar can distort the pump casing and damage internal clearances. The collaring itself must be inspected for corrosion and fatigue, especially where water contact occurs. In deeper mines, thermal cycling from varying groundwater temperatures can loosen bolted collars over time, necessitating regular retightening as part of scheduled maintenance.

The term collaring, though largely restricted to traditional deep-shaft and deep-well pumping, persists in heritage mining contexts and in legacy installations still operating in historical mines. Modern mining operations have largely replaced fixed-column pump systems with more flexible submersible units and above-ground discharge arrangements that reduce or eliminate the need for collaring altogether. Where it remains in use, proper collaring specification remains essential to pump longevity and safe water extraction.