This is a functioning industry-enabled facility for loading coal into river barges. Basically, this is just the dock portion of my 'Rail to Barge Coal Transfer Facility' (kuid2:124017:10114:3). At a minimum, you will probably want to run a conveyor to the dock's loading building.
The industry supports moving loading. I set the maximum allowed speed for the loading somewhat high (~ 11 mph) so that you don't need to be extremely precise with your speed, but for more realistic operation, try to stay around 5 mph while unloading trains. Vulcan's ore barges (kuid2:60238:15041:1) work best with this industry while loading with a speed of 3 to 4 mph.