How to start multiple AI trains on same track?

[Neptune50006]

I'm trying to make a scenario for the Aln Valley route. I would like to have two AI services start at the Morpeth end of the route, 10 minutes apart, call at Alnmouth and then disappear into the portal at Berwick upon tweed.

How do I do this? Can I put the two services into the portal somehow? I've tried starting them one behind the other on the same piece of track, but the first one blocks the second one's signal block, (which makes sense).

Any help would be appreciated.

Thanks.

[Neptune50006]

OK, I've done a bit more research and it looks like AI services can't be started from portals

[FoggyMorning]

OK, I've done a bit more research and it looks like AI services can't be started from portals

Kinda sorta. Some people have reported success in starting AI from portals, but it seems to work only in an absolutely ideal set of circumstances (I think the first signal block being empty at the start of the scenario is one of them)/ I've never got them to function consistently as a start point

[hertsbob]

Hi

I've done/do it with reasonable reliability.

I would point out, however, that as soon as I have an AI train starting from a portal when I'm writing a scenario I have a SBHH error every time I save from that point onwards. Still seems to work OK for me though.

Cheers

Bob

[AndiS]

Basically, don't put two (or more) AI trains in the same block. It is simply a no-no, in real life and in the game.

Route builders are encouraged to provide long enough stubs near portals, with a few block signals. Lacking that, you need to search for an alternative initial location for the second train.

[hertsbob]

It's just occurred to me that maybe the reason I don't seem to have too many issues with this is because I tend to use one portal per line, rather than a shared portal for up and down lines.

This does not detract in any way from what Andi has said above.

Cheers

Bob

[alanch]

Basically, don't put two (or more) AI trains in the same block. It is simply a no-no, in real life and in the game.

From my scenario experiments on the Westhouses route, I've found that you can park many AI trains nose to tail near the end of the route, and as long as the intervals between them starting are long enough, they will work as planned. I try to make sure that the first to start has cleared a signal block before the second starts, and so on.

It's just occurred to me that maybe the reason I don't seem to have too many issues with this is because I tend to use one portal per line, rather than a shared portal for up and down lines.

This didn't work for me on Westhouses, which has single track portals - hence my alternative method above.

[Neptune50006]

Thanks for the replies so far.

Basically, don't put two (or more) AI trains in the same block. It is simply a no-no, in real life and in the game.

How many signals form a block in RW?

It seems daft that there's no simple way of starting more than one AI train from the same point, you could do it in MSTS!

[alanch]

It seems daft that there's no simple way of starting more than one AI train from the same point, you could do it in MSTS!

Did you see my comment? It might be worth a try.

From my scenario experiments on the Westhouses route, I've found that you can park many AI trains nose to tail near the end of the route, and as long as the intervals between them starting are long enough, they will work as planned. I try to make sure that the first to start has cleared a signal block before the second starts, and so on.

[Neptune50006]

Did you see my comment? It might be worth a try.

Yes Alan I did, but all I got was error messages saying occupied block in the editor!

[FoggyMorning]

The "shared signal block" error is only a warning and doesn't (in theory) cause the scenario to fail. Might be worth trying to play the scenario with that message still in place

[AndiS]

In my above statement, I was -- by intention -- overly strict / overly clear.

The above statements show the wide spectrum of approaches. For me, the various options have the following aspects.

If you have a single block signal between each pair of AI trains, you cannot mess up. If there is a congestion, or if you mistyped a departure time, or you forgot something or otherwise lost it, you will see what you have done. Any prematurely started train will proceed to the next signal and stop there. But you need these block signals there, and they are rarely there.

If you line them up nose to tail, you have a good overview and don't need block signals. If you do the proper planning, which is not rocket science, it will work out perfectly. You get this warning or error message, but you can ignore it if you know what you do. If you mess up, you get an AI collision. Its time of occurrence may directly point to the one starting time which is wrong. However, it could also be an unexpected congestion somewhere.

If you stick them into a portal, you save space in the approach, but you loose overview. Don't ask me about further complications, I rarely ever tried them myself.

[Neptune50006]

I solved the problem by going into the rote editor and placing a simple home signal a little way infront of the two AI consists.

Obviously this sort of thing is something that route builders need to take into consideration when building routes. It's a shame that some signals aren't scenario objects, then they could be placed in situations like this to solve these sort of problems.

[TractorBasher]

It would be good if portals could somehow be treated as virtual signal blocks, and the more trains you place into it, the more signal blocks it represents. As each AI train is spawned into the route, it vacates a block in the portal and everything else shuffles up one place. If the block on the route is already occupied, the AI service should remain in the portal until it is cleared. This would make it much easier to produce scenarios with intensively heavy AI services.

[trainsmit]

I'm pretty sure the current warning, when starting a sequence trains from the same portal is a bug introduced sometime after the timetable editor.

Each driver assigned to a train has a starting time, which in case of portal entries is the time the train begins emerging from the portal. The last emerged train must have left the block before the next train can leave thre portal without trouble. There must at all times be at least one home signal (on red) between any two trains.