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) Read the rest