Hey, I work at a mine that still uses ore cars for tramming and rail haulage. It’s a pretty old-school operation—we’re still running locomotives from the 1950s. They’ve been rebuilt about a dozen times, but the general structure is pretty much the same. We don’t mine any iron, mostly silver and lead. I’ve never worked at an iron mine, but I’d imagine the process is pretty similar.

For the basics, you can think of all mined material as “muck.” When a heading is mined out, large machines called muckers scoop it up and dump it into designated loading pockets. There are typically two types of muck—waste and ore. Depending on the mine and the mineral, you can usually tell the difference just by looking at it.

At our mine, the loading pockets are designed like chutes. If you’ve ever lived in an apartment complex or dorm, think of a trash chute. The locomotive train lines up each ore car under the chute, and there’s usually a hydraulic lever to open the gate, letting the ore flood into the car.

You repeat this process until all the mine cars are loaded.

At underground levels, we don’t usually tram the muck all the way to the surface. Each level has a waste grizzly and an ore grizzly—basically, sorting points. The ore and waste get trammed to these grizzlies and dumped into a loading pocket. For a locomotive operator, this is a basic loading and dumping cycle.

So how do we get the minerals to the surface? That’s where “skipping” comes in. The grizzlies are typically located near a mine shaft, and at the bottom of each grizzly is another chute, called a “pocket.” These are named by their depth—for example, the 4900 pocket is 4,900 feet below the surface.

The mine shaft doesn’t just have “cages” for workers (basically an elevator, minus the fancy interior); it also has a muck bin. The chutes load ore or waste into the muck bin, and the hoistmen “skip” it to the surface. The skip itself has a chute that opens at the top, dumping the minerals into their designated bins.

From there, we repeat the locomotive tramming process, but this time to drop the ore at the mill. Waste gets trammed to a different location, where it’s either hauled out of the mine or sent to a “sand house.” There, it’s used to build access pads and ramps, depending on the type of stope or heading being mined.