How do you do Portal's, and where does the train's go when they enter a portal?

To use a portal, place it on a piece of ground in surveyor and connect track to it. then est it up by using the ? button in the objects tab in surveyor. When a train enters a portal, it disappears. You can tell the portal to return it after a certain length of time.
Hi use the ones that come with 06 Portal or portal basic .
You place the portal on a layout and attach railtrack to the entrance end.
Portals can be configured to do different things like if you send a train in it can consume it or you can get it to return the train in x mins.
It can also be configured to produce trains or you may want to use two portals so you can send the train into one and get it to exit the train through the second portal.
The commands are accessed via the ? or properties of the portal.
When I first played trainz I was afraid of portals for some reason. Maybe it was because when I sent trains they never came back? Now I they make me :hehe:
Same here. Now that my imagination has kicked into gear, I have discovered many uses, layouts and designs can be had utilizing the "in's and out's" of portals... pardon the pun.