Problems With Portals


The addition of portals to Trainz many years ago was very welcome indeed, giving users are variety of sources of and destinations for their trains. Unfortunately, portals have a couple of issues that can cause problems. If you’ve ever had a cornfield meet with portal trains or if your trains sometimes get ‘stuck,” then you know what I’m talking about.

There are three principles or “rules” that help explain how portals work. Rule 1 relates the how an inbound train can affect a train leaving the portal. Rule 2 details how long a portal controls a train when it leaves the portal and how an MSD helps you stay out of trouble. Rule 3 explains how a portal will sometimes hold an outbound if it ‘sees’ a train approaching even if that train is miles away.

We’ll explain all this in a .pdf document to be found on dropbox.

The document will also have a link to demonstration route that shows how these rules work.
This is the BEST documentation I have seen for Trainz! It shows the complex original portal system in a professional clear format. However, if I were an early customer this would be a daunting introduction to one of my new purchase's features. Great for current customers but new customers may be stymied.
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There's nothing new here. When an AI-controlled train is emitted, the consist is "blind" to the route and is just a consist being emitted. The consist will ignore all trackside signals and speed limits, will follow default switch settings, and will blindly plough right into other consists in the way.

The solution for this is to ensure that the consist is fully emitted from the portal prior to encountering any other consists or junctions. The way I get around this is to place portals on another baseboard attached to the route. This may not be a pretty solution, but this can be remedied by extending the landscaping further down if you want. I have found too that placing a Wait... 20 seconds as the first command in the command queue gives the AI a chance to get its sea legs under it, so to speak, prior to loading up the rest of the driver commands also helps.