Signalling help needed - diagram provided

jivebunny

Not bugs bunny.
Hi All,

I'll get straight to the point :)

I have a double-track mainline with a crossover and junction leading to a single-track branch line, which itself contains a passing loop a few miles further up. The blue triangles represent the track direction markers. This passing loop (specifically signal S2) is where I want to hold a train if another train is either:

a) approaching signal S3 and travelling towards point A, or
b) approaching signal S1 and travelling towards point B


I have used the Set Signal Extended rule to force S2 to danger if anything activates trigger T1 or T2, both of which have a large radius. The location of trigger T1 ensures it is only activated if junction J1 is set to diverge. Ideally I would have another set of signals between J1 and J2, but I'll leave that for now.

Everything works fine for situation a). If anything activates T2, signal S2 changes to danger and stops train #2 until the main line is clear again. The problem occurs in situation b). When a train activates T1, signal S2 does change to danger, however train #2 takes control of junction J1, preventing Train #1 from getting to point B and causing the inevitable gridlock.

My question is, can I make train #2 let go of the junction while signal S2 is at red? Or even better, can I prevent it from taking control of them in the first place? As this line will be used as a diversion route, both deliberately and by the AI, I would like to do this using only triggers and rules rather than assigning commands to any specific train. Ideally I would have something along the lines of "activation of T1 sets S2 to danger and releases J2 from AI control"

Any help or suggestions would be greatly appreciated!

Cheers,

JB

signalsxk6.jpg
 
Last edited:
I seem to have fixed it but I thought I'd post anyway in case others have a similar layout problem. I placed a small-radius trackmark after signal S2 but before junction J2, and told Train #2 to "Drive Via". As the signal is already at danger (triggered by Train #1 activating trigger T1), Train #2 simply sits at the signal waiting to get to the trackmark, and since it won't attempt to find a path to the next trackmark until the "Drive Via" command is complete, junction J2 stays free to be controlled by Train #1, which can now safely reach the passing loop.

And to top it all off, I can now have signals dotted along the single-line portion for added realism, the trains simply won't enter until the whole section is clear.

If anyone has any ideas as to how this could be done purely through triggers I would be very eager to hear :)

Cheers,

JB
 
I was hoping someone would explain it with triggers, I have this problem so much and haven't found a perfect answer.
 
I seem to have fixed it but I thought I'd post anyway in case others have a similar layout problem. I placed a small-radius trackmark after signal S2 but before junction J2, and told Train #2 to "Drive Via". As the signal is already at danger (triggered by Train #1 activating trigger T1), Train #2 simply sits at the signal waiting to get to the trackmark, and since it won't attempt to find a path to the next trackmark until the "Drive Via" command is complete, junction J2 stays free to be controlled by Train #1, which can now safely reach the passing loop.

And to top it all off, I can now have signals dotted along the single-line portion for added realism, the trains simply won't enter until the whole section is clear.

If anyone has any ideas as to how this could be done purely through triggers I would be very eager to hear :)

Cheers,

JB

That's what I was thinking when I read your first post...

regards

Harry
 
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