AI Trains not stopping at red signals

[MustanGrande]

I'm encountering a problem with my first layout, and I was wondering if anyone could help me. My route uses a single track mainline with passing loops spread along it at regular intervals.

The loop is laid out like so...

As the trains, (A pair of 2-8-2 Mikados with no payload) near the passing loop, they trigger their respective approach signals, causing the divergent signals at the start of the loop to indicate a caution on the main line. The departure signals at the end of the loop turn red, indicating that the train should stop in the side track until the other has passed.

This system works well, except for one problem. When the train, traveling 40 mph, sees the yellow signal at the switch, it tries to slow down to half speed, but it doesn't seem to "see" the red signal at the end soon enough. It brakes too late, and inevitably slides back onto the main line, obstructing the track at best, and at worst, causing a collision.

Has anyone else encountered this problem before, and if so, how did you solve it?

 

[Dermmy]

There are a couple of possible fixes, but first - which Trainz version are you using?

 

[MustanGrande]

Ah, sorry about that. I'm using TS2009.

 

[Kennilworth]

Hi

I think that there are two possible causes and solutions for this.

1) The locos are seeing the signal too late and don't have enough time to stop before the red signal. Try moving the signal further away from the switch to give them more time to react.

2) The locos may need to have the max-dec tag increased in their engine spec files to give them more stopping power. This will only affect DCS and AI locos and have no effect on cab mode.

I would try 1) first as its the easiest to do.

Regards

Brian

 

[fran1]

Forget AI brake, in trainzoptions (found in the folder where 2009 is) add this line. -autopilotsignaldistance=1200
You could also alter (up) the max decel in the locos config file.
Put a track mark in the loop, use drive/navigate to t/mark. Placing the t/mark far enough back to give them time to stop.
Take your pick out of them and see which works best for you.

 

[MustanGrande]

Thanks for the advice!
I think I worked out the problem. Testing with SD40s, which stopped quicker, seemed to cure the problem. Since these particular locomotives seem to have trouble stopping, I installed some 15mph speed limits in the run-ups to the sidetrack. It slows traffic down a bit, but it allows the train to stop before it reaches the signal and trips the 2-minute emergency brake.