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viewtopic.php?f=11&t=68047

What did you do?

I have a number of identical (well nearly some are going forwards and some reverse) dbl header trains that all have the same configuration of wagons / locos and fuel. These trains are running on parallel tracks and clocked to leave on exactly the same tick. But some of the trains have never traveled in reverse.

What happened?

Even though all the trains leave at precisely the same tick and accelerate perfectly in sync upto 298.1 kph. However, some of them arrive at the next station a few ticks earlier than others. Further investigation shows that the trains in reverse break suddenly from 298.1 kph to 259.2 kph in a single tick whist the forward facing trains brake normally. Nb some of the trains break to 270.9 kph expect they had some rocket fuel in them at some point or something like that.

The linked save is paused in editor mode 1 tick before the trains start to brake into the stations.
https://drive.google.com/open?id=1GKdri ... 7dJrbsnSwG

What did you expect to happen instead? It might be obvious to you, but do it anyway!
I expected all the trains to stay in sync, brake smoothly and arrive at their destinations on the same tick.

NB Random googling suggests that this single tick deceleration would inflict ~60G on the player if they were riding the train at the time, although this would hurt like hell, its probably survivable as its only for 1 tick.

I believe the issue is in Train::updateSpeed()

that contains this line

double maxSpeed = this->maxForwardSpeed;

Clearly this should be conditional on the train direction.

Not sure if this should go in its own report or not, but I think it is very similar.

If a train is heading to a station (either temporary or part of a route), the station is removed from the train's station list, and that is the only station in the train's list, then the train will instantly come to a full stop. A deceleration from ~300 Km/h -> 0 would be equivalent to ~510 standard gravities of acceleration (5,000 M/S^2), which is very much not survivable (With F=MA, assuming the average mass of a human is 62Kg, this deceleration would inflict 62*5000=310,000 Newtons).

In this case, I would expect the train to either brake at its normal braking rate (based on tech researched) to a stop, or coast to a stop (as if you had turned the train from "automatic" to "manual"). I could see this going either way.

So this behavior is both lethal for passengers and inconsistent.