Long trains and physics

[artimrj]

Since no one is talking about this I am assuming no one saw it on the other forum. Big Vern was having fun with his new RS11 model and made a scenario to play it. It was too long to finish in a session so he did a save and loaded the save the next day or some other time period. The train started acting funny for him after the save and he didn't understand why. So he posted about it. Low and behold the guy that did the physics for the RS11 (Maik), saw the thread and joined in.

The problem is that TS calculates the train length, weight and tractive forces at the start of the scenario. If your scenario starts with two engines, that is the calcs that are in place. If you hook up to a consist the calcs are now not correct. If you save after hooking up a consist and start the scenario later, all the new calcs, including your new consist are now in play. So you went from cruising with a full train in the original play, to having a loaded down pig in the playing of the save game.

So my theory is if you are hauling a big train up a hill and you are doing 35 in notch one, then you obviously think the physics are bad. From what they have said, if you save while on that hill. When you resume play you should have correct or at least different physics than before the save. This is also assuming you hooked up to the consist and only started the scenario with your engine units.

It was suggested to scenario writers to make the consist and engines together at the beginning of a scenario to have correct physics and not hook up to the consist and go on a run. Or don't resume a save.

[imnew]

Interesting read. Thanks !

[Bananarama]

That's some bad mojo. Thanks for posting the info, Bob.

[Chacal]

It was suggested to scenario writers to make the consist and engines together at the beginning of a scenario to have correct physics and not hook up to the consist and go on a run. Or don't resume a save.

Or purposely save and reload after hooking up to a long train, so you continue with correct values.

[artimrj]

It was suggested to scenario writers to make the consist and engines together at the beginning of a scenario to have correct physics and not hook up to the consist and go on a run. Or don't resume a save.

Or purposely save and reload after hooking up to a long train, so you continue with correct values.

I thought that too ChacHAL, but I was afraid I would hear "You mean we have to save and restart to get proper physics??!!! This sucks!!!!" and all that....

[GreatNortherner]

Or purposely save and reload after hooking up to a long train, so you continue with correct values.

There may be another issue with that though -- could this be why you always get in an immediate derailment when resuming a some saved scenarios? When the train suddenly gets a lot more drag and friction while it is on a grade, or has slack running in/out?

[Chacal]

Quite possible.

[wackyhuman]

I played with this in a scenario for Munich-Augsburg where you start with the engine away from the train you are going to be pulling. The engine (a BR101) is really responsive when driving up to the train, as you would expect for a single engine. Once you hook up to the cars (30 loaded containers), the reaction of the engine is clearly different and it does not jump ahead anymore when using the throttle, it actually feels like a loaded train instead of a single engine. The same when braking for the red lights in the scenario, it takes longer than the single engine would do.

I did not save the scenario in the mean time, but still the physics seem to have changed when I hooked up to the train.

[thecanadianrail]

I played with this in a scenario for Munich-Augsburg where you start with the engine away from the train you are going to be pulling. The engine (a BR101) is really responsive when driving up to the train, as you would expect for a single engine. Once you hook up to the cars (30 loaded containers), the reaction of the engine is clearly different and it does not jump ahead anymore when using the throttle, it actually feels like a loaded train instead of a single engine. The same when braking for the red lights in the scenario, it takes longer than the single engine would do.

I did not save the scenario in the mean time, but still the physics seem to have changed when I hooked up to the train.

im shure the physics do change a bit when you add or take off freight or locos, but its more than likely calculated incorrectly.