5.1.2b: Mine Trucks, Haul Trucks, and Rail (Trains)
The distinction between haul trucks and mine trucks is subtle but important. Mine trucks are generally designed for underground use in more confined spaces. They will have an articulating joint to allow turning in a tighter radius. The capacity will also be less because of clearance restrictions. Nonetheless, capacities of 15 to 60 tons are common. These mine trucks, as pictured here, are commonly used in underground metal and nonmetal mining, and they are as likely to transport the ore directly from the face to the plant as to transport to an intermediate transfer point.
Haul trucks are designed to transport larger loads than mine trucks, and in some underground mines where there is sufficient room, you will find haul trucks. For example, in a salt mine where a 90’ thick seam is being removed, you can fit a large truck of 60–100-ton capacity, although, in underground metal/nonmetal mines, a size of fewer than 60 tons would be more common.
This haul truck holds nearly 450 tons and is in use at a surface coal mine in the Powder River Basin.
Rail haulage was once very common in underground mines, and even in some surface mines. It has the advantage of being able to transport large loads at a low cost. It has fallen out of favor because it has inherent problems that make it unsuitable for many of today’s high production mining systems. Nonetheless, it is still used. In modern coal mines, for example, rail haulage will often be used to transport equipment and supplies, whereas conveyors will be used to transport the coal. The reasons for this will become evident when we look at batch and continuous operations in the next lesson. Rail can be used as an intermediate form of haulage, or as the means to transport the ore out of the mine to the plant. The locomotives and cars used may be of lower profile, like the one shown here.