sorry, you a wrong
the Bavarian system relies upon the Signal Block System to prevent head on collisions. This did not work.
It is not a Bavarian System, its origin came from Token system in GB.
Block System works well, the Signals in Bad Aibling where locked.
But you need a option, if a failure is present on the Line (and that is also for the High-Tec ETCS).
This option is so old as the Railway Signaling, to give the Train Driver a Order (also in ETCS).
It is then on the Signal Man to check out that everything is okay.
And here he failed.
What he did is clear not why and that two times.
What he did:
a) set Route Kolbermoor to Bad Aibling with pressing Signal Button (Start/N) and Line Button (Ziel/X) at the Kolbermoor Part on his Panel.
With that the automatic System Blocks the Signals in Bad Aibling direction Kolbermoor and also the Block Signal 313 (Streckenblock/Line Block).
see here in Flesh:
https://de.wikipedia.org/wiki/Datei:Bah ... rk,_1.jpeg
(Below the red light ist the Zs1 -Subsidiary Signal)
b) a little later he tried to set the Route Bad Aibling to Kolbermoor.The Route comes in but the Signal remains in Danger,because it is locked from
And now the Mistery begins.......at first a little Arrow on the Panel show the Signal Man, that a Train is coming from Kolbermoor (Line Block) and at second
himself sets this Route.
Until now it is all in a safe state.Signal in Danger and without permission the Train could not pass it because that is locked by the PZB plus the Overlap.
But the Tragedy starts with the poor Signal man gives Order Zs1 to Train.
The Train proceed to Bad Aibling Kurpark, the next Passenger Stop and comes there to Stop again.The Automatic Block Signal 313 is locked too.
From the other direction the Automatic Block Signal 314 is in Danger,too because the Train at Bad Aibling Kurpark occupies its Block section to Bad Aibling.
And now the fatal mistake of the Signal man happend, he gave Zs1 again,so the Train moved on and unfortunally the other Train from Kolbermoor
is short (a 100 Meter) behind the Distant Signal to the Block Signal 314 when the Collision happend.
But why he did it is the great Mistery.