[engmod]

>What does surprise me about the information provided by Erik is that large diesel electric locomotives in USA have mechanical compressors (rather than electric).

Emd have engine driven compressor,
GE have electric compressor.

[Laci1959]

 railguy, on 01 October 2021 - 06:49 PM, said:

That explains something that I've noticed on the GE's. When the compressor fires up (with the characteristic "whoop"), you will often hear the prime mover blip up slightly in RPM--probably to Run 1, then drop back down when the compressor shuts off. Now that makes sense, the prime mover "blip" is the engine picking up enough RPM so the compressor goes into higher air production mode.

Hello.

In the mid-1960s, the first stage of the locomotives designed at the Ganz-MÁVAG locomotive factory was the air-producing stage (notch). The engine was running at a slightly higher speed and correspondingly higher power. Its use depended on the driver. If there was no need to produce air, he crossed that notch at departure.
We could not use this in the ORTSDieselEngines block because the next notch was already at a lower speed again and this could not be evaluated by the OR.
If this development succeeds well, will the interpretation of the ORTSDieselEngines block also change?

Sincerely, Laci 1959

[Weter]

Hello.

Quote

you will often hear the prime mover blip up slightly in RPM

please, don't see any attempt to argue here - I just adding my conclusions now:
As prime mover has combined governor (that considers not krankshaft's rotation speed only, but takes in account current load of generator)-
When compressor's motor starts up and brings driven machine to stable speed, it consumes increased current (caled "starting current"), relative to even it's nominal value.
Pumping up air system with given large volume in such short period (few minutes) demands considerable power ~40kW. So starting current is usually up to nominal times 5. This way, prime mover "feels" significantly increased resistance, during compressor's start (especially against pressure, when system is filled), so governor increases fuel flow and generator's EXCITATION (right spelled this time?) to establish meeting this power output demand. Starting compressor "retards" crankshaft, so governor counteracts with that.
After compressor turned off, governor returns its setting to idle.

[pschlik]

That doesn't apply so much to modern microprocessor controls. heck, I'm not even sure anything built in the last 20 years has an "actual" governor or load regulator, it's all sensors and programming figuring out what parameters will provide the desired performance. This leads to all kinds of interesting behaviors, like EMD locomotives which will actually intentionally increase engine RPM literally just to speed up the compressor.

In the specific case of a GE locomotive, what probably happens is that the locomotive exits skipfire when the compressor starts. An idling GE locomotive will not use the full engine firing sequence, instead skipping certain cylinders entirely so it uses the bare minimum amount of fuel to keep the engine turning at idle speed. Of course, you add even the slightest bit of extra load to the engine and you can't keep that same RPM, so it would have to start firing on all cylinders like normal. The RPM change would be minuscule, but a skipfiring GE sounds entirely different to one that's idling normally.

[Weter]

Oh, yes. Here's the same. Half of cylinders are off when idling and run1(if no load), higher settings or auxiliary loads cause rest cylinders to be turned on.

[SP 0-6-0]

Hi,

Please excuse me if this is already possible. There is too many builds of ORTS to keep up with now for me.

I'd like to see rain collect on the windows and be cleared by the wipers,

Rain 1

This feature is also available in SimRail 2021.

Rail 2

This should also work for snow too.

I just sent Chris "CJakeman" this link about 2d lightning effects. Hopefully James Ross can make this a reality in ORTS very soon. 2d Lightning

I hope this makes a new build of ORTS very soon. Lightning would be a very nice touch for running over desert rails. I have a couple ideas for activities in stormy weather LOL.

Thanks.

Robert

[ErickC]

 Csantucci, on 27 September 2021 - 11:36 PM, said:

I've tested steamer_ctn's latest patch in the Unstable release for mechanical compressors, and it's OK to me. Now compressor sound changes (or goes on and off) as it should.
It would be nice if ErickC and/or railguy test it too.

I just tried the latest unstable build (U2021.10.03-606) and the compressor is still always running, sorry. Maybe something in a subsequent automatic build snuck back in.

I have now tried the latest testing version and everything works fine. An earlier post mentioned compressor output being tied to engine RPM. When was this implemented? Was this always the case? If not, is there a flag to enable this feature so that it won't affect legacy content? The only reason I ask is because it seems to be taking an inordinately long time to pump up the brake pipe on trains with even only a couple of cars in this release, though I could be imagining things.

[railguy]

 pschlik, on 02 October 2021 - 09:04 AM, said:

That doesn't apply so much to modern microprocessor controls. heck, I'm not even sure anything built in the last 20 years has an "actual" governor or load regulator, it's all sensors and programming figuring out what parameters will provide the desired performance. This leads to all kinds of interesting behaviors, like EMD locomotives which will actually intentionally increase engine RPM literally just to speed up the compressor.

In the specific case of a GE locomotive, what probably happens is that the locomotive exits skipfire when the compressor starts. An idling GE locomotive will not use the full engine firing sequence, instead skipping certain cylinders entirely so it uses the bare minimum amount of fuel to keep the engine turning at idle speed. Of course, you add even the slightest bit of extra load to the engine and you can't keep that same RPM, so it would have to start firing on all cylinders like normal. The RPM change would be minuscule, but a skipfiring GE sounds entirely different to one that's idling normally.

My emphasis above in italics. EMD 710 equipped locomotives do much more with idle speeds than anything that has to do with compressors. The locomotive's prime mover control system will only allow the prime mover to drop to "low idle" RPM (to conserve fuel)--if engine coolant temperature and numerous other parameters are within a certain range. As far as I know, air compressor operation is NOT one of the parameters that will, on its own, send the prime mover into "high idle" (roughly equivalent to Run 2). If any of the other parameters are "violated," the locomotive prime mover will go into high idle and remain there until all parameters are once again met. This is why an unattended EMD 710 equipped locomotive will pop itself into high idle for awhile, then go back to low idle. Add if Automatic Engine Start Stop (AESS)is active, and the system may shut down the prime mover altogether if another full set of parameters are met--including, for example, reverser centered, ambient outside temperature above freezing, etc. This prime mover behavior and AESS is something that I wish OR would model.

As for the GE's, the "skip firing" is likely why an idling GE often sounds like it is "loping." Thoughts? Old Alco's often loped at idle because the fuel injectors would often have issues at idle. I've heard them lope so badly that only the governor and heavy flywheel would keep them running.

[FS.E652 091]

 SP 0-6-0, on 02 October 2021 - 07:52 PM, said:

Hi,

Please excuse me if this is already possible. There is too many builds of ORTS to keep up with now for me.

I'd like to see rain collect on the windows and be cleared by the wipers,

Rain 1

This feature is also available in SimRail 2021.

Rail 2

This should also work for snow too.

I just sent Chris "CJakeman" this link about 2d lightning effects. Hopefully James Ross can make this a reality in ORTS very soon. 2d Lightning

I hope this makes a new build of ORTS very soon. Lightning would be a very nice touch for running over desert rails. I have a couple ideas for activities in stormy weather LOL.

Thanks.

Robert

The tutorial you attached is really interesting !! I sincerely hope that as graphics this simulator will be improved in many points .. starting precisely from the atmospheric phenomena ... lightning for example, as well as the sound of thunder, is something that is missing on Open Rails .. and I would say that it is a deficit since on Msts this was made possible thanks to Kosmos ...
There has been a lot of talk about this topic and I think that many users like you and me, would like it to become possible ..!

I hope it can become a reality, surely the atmospheric phenomena give more charge to the simulation and make everything more stimulating ..
I would also say that a weather tracking system should also be implemented via network connection, as well as on Flight Simulator ... in fact, depending on the area you are in, the weather can vary based on the coordinates and real weather data .. !!

And why not ... maybe add something that can correlate the wind speed with the animation of the trees ... it seems strange that maybe during a rainy or windy day, the trees are still ...

There is certainly a lot on this side to work with, and I hope it will be made possible ...

[BB22210]

Hello,
Our wish (because we are many trainimers) would be to have a true 64-bit version, with a graphics rendering process capable of running on several cores (really crippling), capable to compete with the TS2021 in terms of performance and graphics quality, which is gaining more and more followers despite its exorbitant costs (routes, rolling stock) and its signaling bugs and the poor choice of routes ;)
Could this major topic be added in the Trello ORTS project management : https://trello.com/b...n-rails-roadmap ?

However I look forward to seeing you at the next models/simulator greatest exhibition which will take place at 30 & 31 of October 2021 in Chambéry (France) on 13,500 m²

BR
Christopher