Mining equipment
Shaft-clearing clamshell grab
Emptying an old, flooded shaft of backfill from the surface, an aggressive clamshell grab deployed down the shaft, working underwater.
Reopening an old mine shaft often means clearing it of years of backfill, gravel, rubble, broken concrete plugs, frequently under water. We designed a heavy clamshell grab to do exactly that, deployed down the shaft from our Articulated Headgear System: it digs the backfill out from the surface, lifts it clear and dumps it to one side, with no one in the shaft. It handles mixed, compacted material and works fully submerged in a flooded shaft.
What it clears, and how
- Aggressive digging – welded sacrificial teeth break compacted material; clears crusher dust, pea gravel, cores, broken concrete and rock (densities ~1.8–2.8).
- Works underwater – designed to operate fully submerged in a flooded shaft.
- Fail-safe – a grab-mounted reversible electro-hydraulic power unit fed by the trailing cable; the grab locks hydraulically on power loss.
- Surface-operated – deployed and controlled from the surface on the headgear system – no personnel down the shaft during clearance.
| Grab | Clamshell, ~1,000 L capacity, ~1.8 m open/cutting width, sacrificial digging teeth |
|---|---|
| Hoisted load / power | ~4 t hoisted; ~1 m/s; grab-mounted reversible electro-hydraulic HPU (no accumulators/battery) |
| Deployment | From the Articulated Headgear System; underwater-capable; hydraulically locked on power loss |