Cars used for carriage of wine on European railways, and the models (7).
Railway carriage of wine, at first utilized existing wooden barrels. These were loaded into open or closed vans. Later, special cars were developed to take the huge winery barrels, which could be loaded by crane. This bulk carriage was able to reach consumer markets serviced by wine and spirits dealers.
This model represents a closed van loaded with special barrels, from which the product could be pumped into smaller barrels in waiting trucks. I can only guess that hand pumps were widely used. To see a typical wine unloading process, in the distribution to wine merchants across Europe, see this page.
The special cars loaded with large winery barrels were developed in the late 1800s, and looked like this model. This is Marklin model #46763.
These cars ran into the 1950s, though many cars using steel tanks were in use from the 1920s.
Here is an example of a steel car, showing behind the farm wagon. (Liliput model #235497)