This has been a frequently reoccurring topic on the JMRI Users Group and it seems to be a challenge. I found a few seemingly working approaches, that I want to explore here.
One concept is not finalising the barge „train“ prior to building the returning barge „train“ within JMRI, so none of the cars aboard the outgoing barge can be assigned to the returning barge. This ensures new cars arriving on the layout with every newly arriving barge.
As already hinted at, the barges are considered „trains“. Each might simply be called „Outgoing Barge“ and „Incoming Barge“ or even receive names that include the barges name (for example „Northern Provider – outgoing“ or „Northern Supplier – incoming“). That’s not decided yet.
But the most important question needs to address how JMRI handles moving the cars from the yard onto the barge. My plan is to define the complete trackage leading to the barge as a single interchange track, keeping in mind, that the barge „train“ actually consists of three or five blocks of cars that need to be switched at different times (for only two tracks being accessible at any given time). There is some leeway in front of the barge slip for single erroneously assigned cars, but there isn’t much tolerance.
So some research is necessary:
- Can JMRI build multiple short trains into one single large train?
- Should JMRI perhaps build one short train for each track on the barge? And handle them as different trains?
- Should every track on the barge be considered an interchange track that for example receives cars on even weekdays and provides cars on odd weekdays, omitting Sundays?
- When cars pass over the barge RFID reader and they are written off into the shelf/storage/staging. Does this affect the handling of the trains on the barge, or the barge „train“?
There is a lot to consider, for sure. I will make descisions that might prove inoperable, but I will learn.