what is the purpose of the gatx tank trainer?

what is the purpose of the gatx tank trainer?
http://rrpicturearchives.net/showPicture.aspx?id=228554

Travels to various industries, to train operators on the various types of valves, and procedures, for loading and unloading tank cars. There are literally dozens of different valve types, nozzle connections, placements and procedures to safely open/operate them. This will train employees at any given plant the correct and safe way to operate the various valves that might appear in cars they are servicing. Classroom is located in the boxcar, while the actual valve, piping and appuratuces connected with the valves and safety valves, are visible for inspection and training purposes, inside the highly modified tank car.

cool pic! I got pics of the two Potash Corp tank training cars together in one train 2 summers ago in a West bound CSX Train the cars are green and white with black lettering.