Is anyone writing OR format .eng files?

[plainsman]

Years ago, I accurately modeled almost every North American diesel electric locomotive .eng file in MSTS format (GE_V4.93, v4_7sd, v47gp, v493al, v48ac and others). I would like to be able to write accurate OR format files to model all these units. I don't know if anyone is yet creating the file format (and what you need to write the files in that format) so I can explore better matching the capabilities of the new files to the actual prototype performance? Are there any OR .eng file editing papers around?
Bob

[cn bala]

My best bet is that you would have to go over to other forum, Elvas Tower if you are a member otherwise have to register to become a member of that forum. There are several messages related to Open Rails there.

John

[baldwin]

Hi Bob
I do know that there are a number of MSTS parameters that OR does not use, NumWheels is one of them. You might well get a better response over at Elvas where most if not all of the devs hang out. Having used your physics in OR, I can say they do perform pretty much the same as MSTS.

The actual adhesion model can be tweaked in the OR options menu ranging from almost impossible to drive up to stick like glue.

PS: If you have not already done so, http://openrails.org/ is the official site. Have a look on there for the manual, or if you have downloaded any updates recently, I think there is a version included there.

[plainsman]

Thanks guys, I did post a couple of threads over in Elvas Tower already, but I thought I would see if anyone over here was creating OR format files. Thanks, and I will await replies over there.
Bob

[OTTODAD]

Hi Bob !

Dekosoft have started releasing new versions of their locos, coded specifically for use by ORTS.

You could get the Pro version of the one below and learn something from looking at the code of the files used by it ?

This is more of interest to those who drive locos from inside their cabs.

I am a tracks and scenery fan and prefer to drive trains from outside their cabs to see much of what good scenic routes have to show and am less concerned with locos physics !

[crstagg]

Bob,

One of the features of the language used to code ORTS is the new Parameter "Include". It can be used in ENG files similar to aliasing Cabs and Sounds. Example: If one was creating a set of GP-9 engines all using the same Lighting, instead of writing a Lights section in one ENG file and then copying it and inserting it X number of times in each of the other ENG files, one could create a Include file named for instance "GP-9-Lights.INC" and place it in a "Common" folder in the Trainset. Then in each ENG file just place a single line in all the ENG files the place in of the lighting section something like "Include ( ..\\Common.Lights\\GP-9-Lights.INC )"

The other feature is having within the engine or wagon folder a sub folder named OpenRails which could contain a second ENG/WAG file that would only be read by ORTS with parameters that would supersede the ones in the original ENG/WAG file or additional Parameters that are unique to ORTS.

See section 8.14 in the ORTS Manual.

[plainsman]

Thanks Charles! Sounds like I need to find the ORTS Manual.
Bob

[crstagg]

Thanks Charles! Sounds like I need to find the ORTS Manual.
Bob

I just noticed that the one at http://www.openrails.org/learn/manual-and-tutorials/ is still the 10 Feb version. Latest is 1 March. I get it via SVN not sure where other "public" downloads are. I posted on ET that it did not have the latest.

One change in the 1 March ver was that the Sound line in the example 3dCab section was removed. See http://www.elvastower.com/forums/ind...ab-sound-line/

You might want to look at other topics in the OR Discussion forum on ET. I recently posted a question on the ENG Buffer section.

[tbundy1982]

I've been dabbling with some engine files that have OR specific settings and additions. It started with trying to get my Monon BLW payware to stop smoking badly. I have studied the forums, manuals and internet for info, as well as guess & check testing. I don't believe I have a full understanding of it all yet but I'm getting there.

The method that I have used so far is to create a new folder named OpenRails inside the locomotive's folder and copy all the .eng files to it. Then I go through and change all the info to suit that particular locomotive. I understand the reasoning for the Include( feature but I'll wait til the fiddling and testing is done. I actually replace over 50% of the figures in most eng files.

Other than scouring internet search engines for specific data, the operating manuals at the Fallen Flags site have a wealth of information.

Some data is hard to find (i.e. brake stuff ) and I've had to just guess based upon my own experience and check with as many sources as I can locate. I'm not sure how much of the wagon brake section has to do with player operation, but it seemed to be in control of the trailing units in MSTS. I don't think I've found the right combination of figures to "boxcar" a trailing locomotive and have it react the same as the leading unit.

Here's a good question: does anyone know how to make tractive force curves for locomotives? That seems to be a well-defined way of controlling power. I have had to settle for Throttle-RPM and RPM-Watts tabs and they work pretty well. I detailed a PC E7 and got the 2 separate engines going and contributing their own horsepower.
I don't know if there is a method to link engines with particle emitters yet. My own wishful thinking would suggest that by linking particle emitters to engines, we could then have an E-unit engine file with, say, 4 engines: 2 standard 12-567 diesel-gen sets emitting their exhaust out of 1-4 stacks per engine, plus 2 steam generators emitting exhaust from the roof and steam from the designated areas. It would actually be nice to have a way to link particle emitters to passenger and freight cars as well.

It's been a fun learning experience, but tedious just the same.

Tyler

[scottb613]

Hi Folks,

I think the latest version of the manual is located here:

http://bazaar.launchpad.net/~twpol/or/trunk/files/head:/Documentation/

[ericson38]

We have loco simulators where I work (just train handling with less than MSTS video visualizations, but with real control stands. I have developed several freight and passenger locomotive speed-tractive effort curves, in excel, that the SW team loads into what we call locosim. I can post a spreadsheet for a P-42 speed-tractive effort if that is what you are refering to.

[UP_4848_Thunder]

I have experimented quite the number of ORTS new eng. parameters along with other MSTS parameters but still await more to be made, along with other info seeking on some of these new parameters. I have been under the braking, traction, fuel an rpm desk lately an so far satisfied with what has come.

Since I put custom traction curve building to a pause due to some findings that traction curves go up too fast (as there is no delay run up traction time parameter readings in ORTS yet like MSTS) than my rpms change rate that they tend to get stuck an produce no more power... realistic for those that open the throttle too fast to much blowing a piston making smoke stay thick but I think a delay traction time parameter is needed especially for my GE's because even a soft gradual throttle can blow it depending on throttle percentage. RPM's do get stuck because the traction curves force exceed the actual max prime mover throttle HP at a speed setting if you set the curves beyond a point or do not have enough smooth speed curves. Most of my EMD curves work well with this due to their fast change rates.

The thing that interested me in the curves an without the curves is a ORTS parameter along in conjunction with even a MSTS parameter that can help realism for DC traction, timing an burning out motors where you are going to have to let them cool idle or a lower throttle settings if you want to gain some traction efficiency. Dynamic braking setting experiments are interesting too.

[plainsman]

Let me explain how to create Tractive Effort curves. I am going to use some simple examples as some units get more complicated, but we will start with a simple first generation diesel. The key relationship here is [Power=Force*Speed], where power is the power at the rail. More specifically then Force(pounds)=Power(hp)*Transmission Efficiency*375/Speed(mph). Now a few caveats, this works well over the common operating range, but has problems at the slow and fast end of the curve. Also, this applies to DC locomotives, AC is more complicated. The problem at the high speed end, is generators tend to run out of voltage, and thus transmission efficiency drops. Also, at the low speed end, transmission efficiency tends to drop. Fortunately, these don't really create a lot of a problem for the following reasons. At slow speeds, you have the final two data points already defined, The adhesion limited tractive effort is flat over the speed range, and the tractive effort at minimum continuous speed is published (you can get those points from the V4.7 to V4.93 files in the library for almost anything out there). At the high speed end, the tractive effort error will not make much difference, as there are so many complicating factors the program can't model that come into play (for example, car shape and arrangement can significantly alter the train resistance at high speeds, and wind and bearing wear and wheel diameter all may overpower the error in transmission efficiency at higher speeds, thus any errors at the high speed end won't matter much, especially for freight locomotives. Now this first curve will apply to notch 8 (full throttle). I will start a new thread with a specific example.

[UP_4848_Thunder]

Ok so it should be way bigger or lower than this with lower curves deep away from the actual power an throttle percentage?

ORTSMaxTractiveForceCurves (
0 ( 0.76 0.85 2.0 0 )
0.105 (
0 92484
3.7 92484
4.42 67724.17
8.9408 11184.6
11.176 8947.7
13.4112 7456.4
17.8816 5592.3
22.352 4473.8
26.8224 3728.2
31.2928 3195.6
33.528 2982.5
33.6 0
)
0.224 (
0 197299.2
3.7 197299.2
4.42 144478.24
8.9408 111846.8
11.176 84940.1
13.4112 74564.5
17.8816 55923.4
22.352 44738.7
26.8224 37282.2
31.2928 31956.2
33.528 29825.8
)
0.386 (
0 339988
3.7 339988
4.42 248966.96
8.9408 228279.3
13.4112 152186.2
17.8816 114139.6
22.352 91311.7
26.8224 76093.1
31.2928 65222.6
33.528 60874.4
)
0.496 (
0 403753.9
3.7 403753.9
4.42 319916
8.9408 269662.6
13.4112 179775.1
17.8816 134831.3
22.352 107865.0
26.8224 89887.5
31.2928 77046.4
33.528 71910.0
)
0.595 (
0 524076
3.7 524076
4.42 383770.32
8.9408 308026.1
13.4112 205350.7
17.8816 154013.0
22.352 123210.4
26.8224 102675.3
31.2928 88007.4
33.528 82140.3
)
0.702 (
0 618321.6
3.7 618321.6
4.42 452784.38
8.9408 322901.7
13.4112 215267.8
17.8816 161450.8
22.352 129160.7
26.8224 107633.9
31.2928 92257.6
33.528 86107.1
)
0.844 (
0 743395.2
3.7 743395.2
4.42 544373.36
8.9408 331290.2
13.4112 220860.1
17.8816 165645.1
22.352 132516.1
26.8224 110430.0
31.2928 94654.3
33.528 88344.0
)
1 (
0 880800
3.7 880800
4.42 644992.13
8.9408 333180.4
13.4112 222120.3
17.8816 166590.2
22.352 133272.1
26.8224 111060.1
31.2928 95194.4
33.528 88848.1
)
)
)

Or even

ORTSMaxTractiveForceCurves (
0 ( 0.67 0.85 2 0 )
0.063 (
0 53525.43
5.2 53525.43
5.3 43997.31
8.9408 19585.12
11.176 17448
13.4112 12315
15.6464 10462.9
17.8816 8680
20.1168 7468
22.352 6499
26.8224 5270
31.2928 5231
32.3 0
)
0.120 (
0 101953.2
5.2 101953.2
5.3 83804.4
8.9408 46765.2
11.176 37012
13.4112 30510
15.6464 25865
17.8816 22382
20.1168 19673
22.352 17506
26.8224 14255
31.2928 11932
32.3 0
)
0.250 (
0 212402.5
5.2 212402.5
5.3 174592.5
8.9408 140612.0
11.176 108489
13.4112 87074
15.6464 71778
17.8816 59306
20.1168 51383
22.352 44244
26.8224 33537
31.2928 25889
32.3 0
)
0.340 (
0 288867.4
5.2 288867.4
5.3 237445.8
8.9408 210397
11.176 167917
13.4112 139598
15.6464 119369
17.8816 105098
20.1168 92398
22.352 82958
26.8224 69799
31.2928 58684
32.3 0
)
0.553 (
0 469834.33
5.2 469834.33
5.3 386198.61
8.9408 286900
11.176 229030
13.4112 190600
15.6464 163021
17.8816 144450
20.1168 128350
22.352 115560
26.8224 96300
31.2928 825
)
0.700 (
0 594727
5.2 594727
5.3 488859
8.9408 317546
11.176 253547
13.4112 211030
15.6464 180534
17.8816 159773
20.1168 141970
22.352 127818
26.8224 106515
31.2928 91298
32.3 0
)
0.860 (
0 730664.6
5.2 730664.6
5.3 600598.2
8.9408 326046
11.176 260168
13.4112 216697
15.6464 185263
17.8816 164023
20.1168 145649
22.352 131218
26.8224 109348
31.2928 93727
32.3 0
)
1 (
0 849610
5.2 849610
5.3 698370
8.9408 327948
11.176 261511
13.4112 217965
15.6464 186222
17.8816 164974
20.1168 146395
22.352 131979
26.8224 109982
31.2928 94270
32.3 0 42
32.3 0
)
)
)

[plainsman]

For first generation diesel locomotives, transmission efficiency generally runs from 80-85%. So lets take an EMD FT unit with 1,000 kW or 1340 gross horsepower and create a curve at notch 8. To begin, the unit has an adhesion limited tractive effort of about 41,475 pounds. This is determined by weight and adhesion, and is essentially independent of power it would be the same if the unit had 250HP or 6000HP. As the speed increases, the tractive effort is limited by the ability of the traction motors to absorb amperage, and thus the minimum continuous speed (again only on DC units is this the limiting factor). For a FT, this is 33,000 pounds of force at a minimum continuous speed of 11 mph. (This is for a freight geared unit with a 65 mph top speed). You will note, this is less than the calculated TE at 11 mph, as transmission efficiency drops near the MCS. At 20 mph we have Force= [(1340*0.80*375)/20]= 20,100 pounds. At 30 mph, [(1340*0.80*375)/30= 13400 pounds. At 40 mph, 10050 pounds, At 50 mph, 8040 pounds. At 60 mph, 6,700 pounds, and at 65 mph about 6180 pounds although actual will be a little less at 65 mph. This is all at full throttle. Now to generate the curve for notch 7, you have to know the power supplied at that notch. MSTS incorrectly drops the power linearly with each notch. In reality the power increases exponentially for simple cases like EMD without turbos and many Alco and GE units, but gets more complicated for turbocharged EMD units especially. If you search the threads, you will find a few actual power vs. notch threads from actual observed data. Simply take the observed percentage of power at that notch, times the full power and plug it into the equation for each speed.