A mine railway is a purpose-built rail system designed to transport large volumes of ore, concentrate, waste rock, or supplies between mine operations, processing facilities, and export terminals, using rail haulage as an alternative to truck-based road transport. In bauxite, iron ore, and diamond mining — where the mine may be located hundreds of kilometers from the nearest port or processing facility — dedicated mine railways are critical infrastructure assets that enable the economic extraction and marketing of low-value, high-volume commodities that could not bear the cost of road transport over long distances.
Mine railways in the iron ore and bauxite industries are among the heaviest-haul rail systems in the world. Operations such as Rio Tinto's network in the Pilbara region of Western Australia — spanning nearly 2,000 kilometers and carrying over 300 million tonnes of iron ore per year — use trains consisting of over 200 wagons and exceeding 2.5 kilometers in length, hauled by multiple diesel-electric locomotives. These trains are characterized by extremely high axle loads (up to 40 tonnes per axle) and operating speeds optimized for maximum throughput within safe operating parameters.
The design of a mine railway incorporates specialized civil and track engineering to handle these demanding loads. Rail weight (kilograms per meter), tie (sleeper) type and spacing, ballast depth and quality, curve radius, grade limitations, and bridge and culvert design are all engineered to the specific duty cycle of the haulage system. Positive Train Control (PTC) or Communications-Based Train Control (CBTC) systems manage train movements and prevent collisions. In some operations, such as Fortescue Metals Group's Pilbara railways, autonomous train technology now eliminates the need for onboard locomotive drivers entirely, improving safety and operational efficiency.