Rotary car dumpers (aka wagon tipplers) are used for quickly emptying coal and ore from hopper cars. Traditionally, hopper cars emptied from the bottom.
Enthusiast Chester Hill praises Pittsburgh-based Heyl & Patterson, who build these behemoths:
This is the Single Rail Car Dumper that has been in operation over 15 years. Drummond Coal purchased Heyl & Patterson Equipment, and are now building the the first Quad Car Coal Dumper at the Drummond Port in Santa Marta, Colombia.
Here’s a longer clip from a different type that shows the entire process, not just the dumping:
• Heyl & Patterson – Single Coal Rail Car Dumper – Santa Marta Colombia (YouTube / Chester Hill)