In OpenTTD, a feeder service can be created, as per the wiki, using the transfer option when giving orders. As the note at the top of the page notes, this won't work two ways, since the vehicle will simply pick up the same cargo again, resulting in the cargo moving in circles.
The normal workaround, again as per the wiki, is to use two stations next to each other:
This is, however, highly unsatisfactory in my situation, because I need to create a two way transfer system between a bank and a airport, and there's just no way I would build two airports just for this purpose.
Is there another method of accomplishing this?
Best Answer
I believe the straight forward answer is "no"; as you've discovered the load/unload orders you can give to vehicles currently do not allow you to make them ignore the cargo they have dropped off.
However, as a work-around, have you considered a single combined station instead of a feeder service?
Assuming the bank is close enough to the airport (dependent on your settings, more below), you can
Ctrl+Clickwhen placing a loading bay (or equivalent) near the bank, and select an existing near-by station (i.e., your airport) to have the new construction form exactly the same station. Then they share waiting all cargo, ratings, etc - so there is then no need of a feeder service.The maximum spread of a station is an advanced setting that you can change, and defaults to 12. I'm fairly sure it can be adjusted mid-game, if necessary.