We have T2R Europe, and just tried out the 1912 Expansion pack which includes warehouses and depots.
To my knowledge one must put the first train card to any given players warehouse before drawing to themselves. Each player also gets a free action, which is the option to take one or more depots and place them on the map, in their turn.
But here's where the rules are not clear enough. For us that is:
When one player uses their turn to put a new depot onto the map and they also claim a route. Is it then possible to put a depot to a city where they, in the same turn, are claiming that route to?
Here's an example:
You are in Paris, and it is your turn.
First you place a depot in Frankfurt (as a free action).
Then you claim that route: Paris - Frankfurt. When you do that, according to the rules regarding claiming a route into a city where there's a depot, you can "buy" the cards by discarding one of your own depots. But, can you do that in the same turn?
That's like 3 actions in one turn.
1. place depot
2. claim route
3. empty a warehouse
To me that feels a bit too much and a bit suspicious, but how is the rules to avoid such a scenario?