Erm sry if I sounded hostile, that was never my intention. I only meant to show that the design is flawed and please allow me to explain once again why is it flawed.
The design you showed can lead to grid lock if you have 4 or more trains given bad timing no matter how many passing loops you have on the line. You can have 4 trains and 10 passing loops and there is still possibility that gridlock will happen. Please look at the diagram below.
If there is something that needs explaining I am really open for discussion and will try to convey the explanation as best as I can.