This wagon is based on late 19th and early 20th century tank wagons used in Europe. It features a brakeman's cabin that provides shelter for the brakemen who were needed at the time to ride the wagons and operate their brakes.
In game, a player can ride the wagon in the brakeman's cabin. However, actual braking control is not available.
If Advanced Trains TechAge addons is installed and enabled, and Advanced Trains is running at version 2.4.3 or later then this wagon can also be used to transport up to 1000 units of liquid.