The issue of running bi-directional AI trains on a single track with crossing loops comes up from time to time in these Forums. On youtube I've uploaded other "how to" videos about interactive industries and freight cars. I'm in the process of uploading a sequence of three videos showing how to configure track and portals to make bi-directional AI work.
It's based on about five decades of experience mixed with some anger and much frustration. And bear in mind what a retired Marines General said about hi-tech products - "What most people don't realise is that in actual combat anything more complex than a can opener will not work; and even a can opener will not work all the time." So, please, if you follow my tutorials to the letter it is likely that AI will work for you but it is in no way guaranteed.
OK - Tutorial One - Signals and Track Markers.
A simple route with a single track, three crossing loops and portals to emit and consume AI trains.
Always use absolute signals (not permissive). I've used semaphores in this example because it is then possible to see the indications from both sides.
In the crossing loops position the signals as shown - four squares apart. The signals in the single track section are important but not essential (experience has taught me that they do help) as are the signals at the entrance and exit of the single track section.
The signals mid block in the crossing loops help if you intend running freight or passenger trains at suicidally short headways, that is around about the frequency of suburban metro systems. The signals make it possible to store two AI trains per track in the loops.
The Track Markers are set up for North American right hand running. Position them as shown in the video. It makes it easier if they are named in sequences x(01) through to x(99) where x = alphanumeric. The brackets are important. In the example, the anticlockwise Track Markers are a(01) through a(04) and the clockwise Markers c(01) through c(04).
Video here - best watched full screen and in HD:
(CONTINUES)
It's based on about five decades of experience mixed with some anger and much frustration. And bear in mind what a retired Marines General said about hi-tech products - "What most people don't realise is that in actual combat anything more complex than a can opener will not work; and even a can opener will not work all the time." So, please, if you follow my tutorials to the letter it is likely that AI will work for you but it is in no way guaranteed.
OK - Tutorial One - Signals and Track Markers.
A simple route with a single track, three crossing loops and portals to emit and consume AI trains.
Always use absolute signals (not permissive). I've used semaphores in this example because it is then possible to see the indications from both sides.
In the crossing loops position the signals as shown - four squares apart. The signals in the single track section are important but not essential (experience has taught me that they do help) as are the signals at the entrance and exit of the single track section.
The signals mid block in the crossing loops help if you intend running freight or passenger trains at suicidally short headways, that is around about the frequency of suburban metro systems. The signals make it possible to store two AI trains per track in the loops.
The Track Markers are set up for North American right hand running. Position them as shown in the video. It makes it easier if they are named in sequences x(01) through to x(99) where x = alphanumeric. The brackets are important. In the example, the anticlockwise Track Markers are a(01) through a(04) and the clockwise Markers c(01) through c(04).
Video here - best watched full screen and in HD:
(CONTINUES)
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