Hi bustedbenzes,

Are we talking about analog automation?

Assuming yes, you will need a signal for each station track and a universal relay (7245). Both tracks need a circuit track placed at the end of each track just before the stopping areas of the signals. Another circuit track is added somewhere further ahead on the right.

Assume initially there is a train waiting on the upper station track (A) and both exit signals (signal A and signal B) are set to "red". The entry switch is set to "straight". The universal relay is set to "green".

When a train enters the station from the left, it will therefore go to the lower station track (B). When it hits the circuit track, three things happen: (1) signal A is set to "green", (2) the entry switch is set to "turn" and (3) the universal relay is set to "green". Then the train stops at the stopping area.

Meanwhile, the train on track A proceeds out of the station. When it hits the circuit track further ahead, the circuit track will send a pulse to the universal relay which will pass it to the signal A, setting it to "red".

With this, the mirror image of the initial state is established: the waiting train is now on track B, the entry switch is set to "turn" and the universal relay is set to "red".

When the train that just left the station eventually comes back from the left, it will go to the upper station track A and hits its circuit track. This will (1) set signal B to "green", (2) turn the entry switch to "straight" and (3) flip the universal relay back to "green", thus re-establishing the initial state.

The exit switch does not need automation, as trains can pass it independent of its setting.

So, the universal relay stores the state of the system: "green" indicates the the track A is reserved, and "red" that the track B is reserved. (If you are using old-school 70xx signals, you can use one to mimic the operation of the 7245.)

There must be other ways to do this, but this was the first that came to my mind. In all likelihood I may have missed something, so beware! Anyway, something like this will probably fill your need. Consult the Märklin 0340 Signal Manual for inspiration.

Contact tracks can also be used, but they probably require a more complex design to make sure that cars stopping on contact tracks do not burn the solenoids of the switches and the signals. One approach is to use further universal relays to enable and disable contact tracks appropriately. Even circuit tracks may cause problems if the trains have cars with current pick-ups that happen to stop residing just at a circuit track.

If you are doing analogue, this link from Robert Frowenfeld on signals and track laying might be helpful. If the link does not work, please go to his site and the book is near the bottom end of his website.

http://www.rjftrains.com/technical/0340.pdf

I have done this before. Train 1 stops then launches train 2 at the same time flipping the switch at the entrance to the station. It helps if the sidings are long. This gives you more wiggle room when locating the contact sections.
You cannot allow a train to stop on a contact section as something will burn up. I remember I used no relay.
I'll try to draw a schematic. Unless someone beats me to it.

Mikey

How would the reverse pulse be triggered?

Turn the red knob to the left past zero.

I have done this pretty much the way that Mike described. I used a single contact track to set both signals back to red - the one that is already red just stays the same.
One problem will occur when a train has any sliders under the coaches or wagons. When the train stops these may not have yet passed over the contact track that triggers the other train. If this happens a train that is leaving can trigger the other train which will then crash into the side of it.

I use a couple of universal relays 7045 which are switched along with the signals. They are used to 'turn off' the contact track under the departing train (one for each loop) so that any slider that has not yet passed over the contact track doesn't cause the other train to be erroneously released.
A further contact track on the approach to the station switches the relays back on.
You only need the relays if you have lighted coaches or wagons in either of the trains.

It's great fun - loads of collisions while you are figuring out what connects to what......

Haha..... it's a lot easier to do than it is to write about eh Michael

My opinion for what it is worth:
(Trump is halting production of the penny, so now I want nickels and dimes)
I agree with the fact that the 5146 and 5147 units are useless. they sometimes work, which is just not good enough.
I have about 30 of each and they make great make-up sections where I need half tracks.
I leave the moving parts in place, just don't hook them up.
I am using the 5105 and 5104 contact tracks instead, old but reliable.
I am however making sure that they are far enough away from signals so that a train will not stop on it.
But then, I am lucky enough to have enough space to do that.
Automation is great, but I do not just want to sit there and do nothing but look at it.
I actually would like to push some buttons,so I will be about half automated, mostly on entry tracks for the stations. :)
The great advantage of M track and wiring is that I can "split" the wire so I can push a button to overwrite the automation.
Thanks,
Tim

That's a great idea, Bill. Why didn't I think of that. I still won't use them.

Consider to use light gate or IR gates for detction, or the grounding contact tracks and let that control inputs to an arduino.

Using the contact track with that unreliable contact is difficult and even worse if you have some wagons with sliders.