Originally it was built to carry coal for Ontario Hydro, but now that Ontario has phased out coal power generating stations, it can carry grain, iron ore, gravel and other bulk cargoes. John Leitch owned Upper Lakes Shipping, but the business has been sold to Algoma Central, who have kept his name on this ship.
On ships like this, conveyor belts do all the work. They run along the bottom of the ship so the cargo can be dropped down onto them. Then they rise up an elevator and drop onto the 2nd main conveyor belt that runs along this boom, extending onshore. It can drop piles of coal on a dock, or drop grain into a receiving bin for an elevator. All the magic is actually out of sight, and it makes shipping much safer than it has been in the past. Dust control is also much better if the conveyor belts are enclosed in a tunnel. You can find a neat video that illustrates all this here.