OVERLAND CONVEYOR

An overland conveyor is a long-distance, cross-country belt conveyor that moves bulk material in a single continuous flight, typically over distances from 1 km up to 25 km or more. The form factor exists because at large tonnages over long distances, belt conveying beats truck haulage on operating cost, energy consumption, CO₂ emission and safety — by roughly an order of magnitude on each metric — while requiring much less ongoing maintenance once installed.

Overland conveyors are almost always built with [steel cord belt](/glossary/steel-cord-conveyor-belt) (typical ST 1600 to ST 4000) because the long centre distance demands very high T1 and very low elongation; fabric belts simply cannot serve the duty above about 1 km. They use horizontal as well as vertical curves to follow terrain — modern routing software supports curve radii down to 1000–2000 m. Drives are typically multi-motor head-drive plus tail-drive, sometimes with intermediate tripper drives, all coordinated through variable-frequency drives that ramp belt speed and tension smoothly during start-up to avoid carcass shock.

Famous installations include the Bou Craa phosphate conveyor in Western Sahara (about 100 km, one of the longest in the world) and the Curragh coal conveyor in Australia. On a much smaller scale, almost every modern open-pit mine and large quarry has at least one in-pit-to-plant overland conveyor of 1–5 km length. The [friction factor](/glossary/friction-factor) of the belt cover is critical on overland systems — even a 10 % improvement on f translates to 10 % less installed motor power and 10 % lower operating cost over a 15–20 year service life.