[scottb613]

Hi Folks,

Just one FYI about INCLUDE files I noticed after days of troubleshooting an issue - is if you don't have a [white space] on the last line of the INCLUDE - after the last parameter which is typically a close parens - it can mangle the calling ENG/WAG file and render it inoperable... I now finish all my INCLUDES with a [white space] then [newline]...

Regards,
Scott

[darwins]

Well Steamer_CTN put up a better chart than the one I messed up anyway.

The sections there are clearly labelled.

It is common for constant horsepower to make up around 50% of the chart - and most of the important working speed range. Hence why I think in power rather than force.


It is very hard to recreate that with ORTS tractive force curves - it is a matter of how much you want to let power vary - do you put a point every 10 mph or every 5 or every 1? The challenge of making a straight line out of curves!

On the other hand ORTS tractive force curves are brilliant for representing hydraulic transmissions - constant torque = constant force (more or less) all you need is one pair of points for each torque converter stage and you have a near perfect model for your loco output.

It takes only four pairs of points to represent the three camel humps of the Voith transmission.

[ErickC]

steamer_ctn, on 05 February 2020 - 07:30 PM, said:

To make sure that we are on the same page, what version of OR are you running?

I just upgraded to the latest versions of both XNA and Monogame on Monday to test a prototype locomotive built around the recently-added freight shape visibility parameters. I was having no issues before. Check your PMs for some test models.

On the subject of your sample file, I'm more than happy to reorganize my common files for future releases, my big concern now is that patching current ones is going to be a bit of an adventure if the problem persists, especially since one of my locomotive packs just got an update two weeks ago.

[istvanek]

Hello,

First of all I want to say big thank you for OR developers and content creators for improvements in Open Rails physic. The second goes specially to Gerry and Erick for they effort to provide accurate data.

I think that currently we have a problem with a different data formats OR expects for different input data configurations:

1) Simple MSTS input
2) MSTS input with diesel engine section present
3) diesel engine section with Traction Tab (or Traction Curves) present (does here MSTS input data really needed and used by OR?)

What is more, Peter introduced Advanced Physics and now some users can get really confused what data is used and how OR handles each parameter provided. Lack of documentation and explanations do not help (even for long existing features like ORTSDieselEngines Tab). I am not to blame developers as I know how huge effort they take to provide us new functions. Thanks to Elvas Tower we can give them a feedback but still in my opinion there is no clear way documented how to configure ours engine files with data we have.

IE DieselTorqueTab often confuses the one who is trying to configure his loco trying to fill DieselEngines section and there is no explanation what it actually means and when and how this data is used during the sim. Fabric data is hardly available if any. During my research I have found that mid RPM-speed engines (so the ones used in locomotives) are constant gross HP and constant gross Torque in given RPM (it is not so at automotive market where we have high RPM-speed engines). So if engine producer data is unavailable then we can easily calculate the torque which is constant in given RPM:

Torque (lb.in) = 63,025 x Power (HP) / Speed (RPM)

Power (HP) = Torque (lb.in) x Speed (RPM) / 63,025

Torque (N.m) = 9.5488 x Power (kW) / Speed (RPM)

Power (kW) = Torque (N.m) x Speed (RPM) / 9.5488

formulas from: WEN Technologies There is a calculator available too. Note that this is a gross engine torque and not torque to the rails as this vary from transmission and resistances.

But what is the impact of this tab to overall locomotive performance? I do not know :( Maybe Peter or Carlo can answer looking to the code. I have found that it certainly have an impact during starting a train (so at zero speed) but does it have any other?

What is more manual states we should fill this tab with torque numbers in Newtons. But the torque unit is Nm (Newton x meter). Is it a typo or there is an assumption that we have 1 meter arm?

And what about the other Diesel Engine Tab parameters? IE DieselPowerTab, is it used for calculations or is informative only? Running Erick GP9 I have found that engine load can be constantly over 100% in certain notches. So it seems that OR calculates net power and and wheel to rail force from other parameters independently from diesel engine power output defined by DieselEngines Tab. Does it? Or maybe it depends from engine setup (with or without Traction Tab)?

Ah, so many questions :)

Once again thank you efforts to improve Open Rails.

[NickonWheels]

Erick, according to Wikipedia the GP7/9 has 65000lbf starting tractive effort so their traction curves looks like following

ORTSMaxTractiveForceCurves (
0	(
0	0
0.89408	0
1.78816	0
2.90576	0
4.02336	0
5.36448	0
6.7056	0
8.27024	0
9.83488	0
11.62304	0
13.4112	0
15.42288	0
17.43456	0
19.66976	0
21.90496	0
24.36368	0
26.8224	0
29.50464	0
31.2927	0
31.2928	0
)
0.125	(
0	36141.800624
0.89408	36141.800624
1.78816	36141.800624
2.90576	22854.876559
4.02336	16506.299737
5.36448	12379.724803
6.7056	9903.779842
8.27024	8030.091764
9.83488	6752.577165
11.62304	5713.71914
13.4112	4951.889921
15.42288	4305.991236
17.43456	3809.146093
19.66976	3376.288583
21.90496	3031.769339
24.36368	2725.810966
26.8224	2475.944961
29.50464	2250.859055
31.2927	2122.245319
31.2928	0
)
0.25	(
0	72283.601248
0.89408	72283.601248
1.78816	72283.601248
2.90576	54487.901598
4.02336	39352.373376
5.36448	29514.280032
6.7056	23611.424026
8.27024	19144.397859
9.83488	16098.698199
11.62304	13621.975399
13.4112	11805.712013
15.42288	10265.836533
17.43456	9081.316933
19.66976	8049.3491
21.90496	7227.986947
24.36368	6498.557071
26.8224	5902.856006
29.50464	5366.232733
31.2927	5059.607031
31.2928	0
)
0.375	(
0	108425.401872
0.89408	108425.401872
1.78816	108425.401872
2.90576	93881.748669
4.02336	67803.48515
5.36448	50852.613862
6.7056	40682.09109
8.27024	32985.479262
9.83488	27737.789379
11.62304	23470.437167
13.4112	20341.045545
15.42288	17687.865691
17.43456	15646.958111
19.66976	13868.89469
21.90496	12453.701354
24.36368	11196.905805
26.8224	10170.522772
29.50464	9245.929793
31.2927	8717.618806
31.2928	0
)
0.5	(
0	144567.202496
0.89408	144567.202496
1.78816	144567.202496
2.90576	139753.082039
4.02336	100932.781473
5.36448	75699.586105
6.7056	60559.668884
8.27024	49102.43423
9.83488	41290.68333
11.62304	34938.27051
13.4112	30279.834442
15.42288	26330.290819
17.43456	23292.18034
19.66976	20645.341665
21.90496	18538.674148
24.36368	16667.798775
26.8224	15139.917221
29.50464	13763.56111
31.2927	12977.113374
31.2928	0
)
0.625	(
0	180709.00312
0.89408	180709.00312
1.78816	180709.00312
2.90576	180709.00312
4.02336	138158.637598
5.36448	103618.978198
6.7056	82895.182559
8.27024	67212.310183
9.83488	56519.442654
11.62304	47824.143784
13.4112	41447.591279
15.42288	36041.383721
17.43456	31882.762523
19.66976	28259.721327
21.90496	25376.076293
24.36368	22815.18786
26.8224	20723.79564
29.50464	18839.814218
31.2927	17763.31017
31.2928	0
)
0.75	(
0	216850.803744
0.89408	216850.803744
1.78816	216850.803744
2.90576	216850.803744
4.02336	179073.502842
5.36448	134305.127132
6.7056	107444.101705
8.27024	87116.83922
9.83488	73257.342072
11.62304	61986.981753
13.4112	53722.050853
15.42288	46714.826828
17.43456	41324.654502
19.66976	36628.671036
21.90496	32891.051542
24.36368	29571.771112
26.8224	26861.025426
29.50464	24419.114024
31.2927	23023.809655
31.2928	0
)
0.875	(
0	252992.604368
0.89408	252992.604368
1.78816	252992.604368
2.90576	252992.604368
4.02336	223371.474741
5.36448	167528.606056
6.7056	134022.884845
8.27024	108667.203928
9.83488	91379.239667
11.62304	77320.895103
13.4112	67011.442422
15.42288	58270.819498
17.43456	51547.263402
19.66976	45689.619833
21.90496	41027.413728
24.36368	36887.032526
26.8224	33505.721211
29.50464	30459.746556
31.2927	28719.281386
31.2928	0
)
1	(
0	289134.404992
0.89408	289134.404992
1.78816	289134.404992
2.90576	289134.404992
4.02336	270812.031836
5.36448	203109.023877
6.7056	162487.219101
8.27024	131746.393866
9.83488	110786.740296
11.62304	93742.626405
13.4112	81243.609551
15.42288	70646.617001
17.43456	62495.08427
19.66976	55393.370148
21.90496	49740.985439
24.36368	44721.252964
26.8224	40621.804775
29.50464	36928.913432
31.2927	34818.801075
31.2928	0
)
)

ORTSMaxTractiveForceCurves (
0	(
0	0
0.89408	0
1.78816	0
2.90576	0
4.02336	0
5.36448	0
6.7056	0
8.27024	0
9.83488	0
11.62304	0
13.4112	0
15.42288	0
17.43456	0
19.66976	0
21.90496	0
24.36368	0
26.8224	0
29.50464	0
31.2927	0
31.2928	0
)
0.125	(
0	36141.800624
0.89408	36141.800624
1.78816	36141.800624
2.90576	26356.752315
4.02336	19035.432227
5.36448	14276.57417
6.7056	11421.259336
8.27024	9260.480543
9.83488	7787.222275
11.62304	6589.188079
13.4112	5710.629668
15.42288	4965.764929
17.43456	4392.792052
19.66976	3893.611137
21.90496	3496.303878
24.36368	3143.465872
26.8224	2855.314834
29.50464	2595.740758
31.2927	2447.420536
31.2928	0
)
0.25	(
0	72283.601248
0.89408	72283.601248
1.78816	72283.601248
2.90576	63196.750635
4.02336	45642.097681
5.36448	34231.573261
6.7056	27385.258609
8.27024	22204.263737
9.83488	18671.767233
11.62304	15799.187659
13.4112	13692.629304
15.42288	11906.634178
17.43456	10532.791773
19.66976	9335.883617
21.90496	8383.242431
24.36368	7537.22714
26.8224	6846.314652
29.50464	6223.922411
31.2927	5868.288455
31.2928	0
)
0.375	(
0	108425.401872
0.89408	108425.401872
1.78816	108425.401872
2.90576	108425.401872
4.02336	78829.514347
5.36448	59122.13576
6.7056	47297.708608
8.27024	38349.493466
9.83488	32248.437687
11.62304	27287.139582
13.4112	23648.854304
15.42288	20564.221134
17.43456	18191.426388
19.66976	16124.218844
21.90496	14478.89039
24.36368	13017.717966
26.8224	11824.427152
29.50464	10749.479229
31.2927	10135.255662
31.2928	0
)
0.5	(
0	144567.202496
0.89408	144567.202496
1.78816	144567.202496
2.90576	144567.202496
4.02336	117501.291757
5.36448	88125.968818
6.7056	70500.775054
8.27024	57162.790585
9.83488	48068.710264
11.62304	40673.52407
13.4112	35250.387527
15.42288	30652.510893
17.43456	27115.682713
19.66976	24034.355132
21.90496	21581.869915
24.36368	19403.883042
26.8224	17625.193764
29.50464	16022.903421
31.2927	15107.357218
31.2928	0
)
0.625	(
0	180709.00312
0.89408	180709.00312
1.78816	180709.00312
2.90576	180709.00312
4.02336	160972.410395
5.36448	120729.307796
6.7056	96583.446237
8.27024	78310.902354
9.83488	65852.349707
11.62304	55721.218983
13.4112	48291.723119
15.42288	41992.802712
17.43456	37147.479322
19.66976	32926.174854
21.90496	29566.361093
24.36368	26582.599882
26.8224	24145.861559
29.50464	21950.783236
31.2927	20696.518903
31.2928	0
)
0.75	(
0	216850.803744
0.89408	216850.803744
1.78816	216850.803744
2.90576	216850.803744
4.02336	208763.776776
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6.7056	125258.266066
8.27024	101560.756269
9.83488	85403.363227
11.62304	72264.384269
13.4112	62629.133033
15.42288	54460.115681
17.43456	48176.256179
19.66976	42701.681613
21.90496	38344.367163
24.36368	34474.752128
26.8224	31314.566516
29.50464	28467.787742
31.2927	26841.142788
31.2928	0
)
0.875	(
0	252992.604368
0.89408	252992.604368
1.78816	252992.604368
2.90576	252992.604368
4.02336	252992.604368
5.36448	195387.13271
6.7056	156309.706168
8.27024	126737.599596
9.83488	106574.79966
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13.4112	78154.853084
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24.36368	43021.020046
26.8224	39077.426542
29.50464	35524.93322
31.2927	33495.044074
31.2928	0
)
1	(
0	289134.404992
0.89408	289134.404992
1.78816	289134.404992
2.90576	289134.404992
4.02336	289134.404992
5.36448	236960.527856
6.7056	189568.422285
8.27024	153704.126177
9.83488	129251.197013
11.62304	109366.397472
13.4112	94784.211143
15.42288	82421.053167
17.43456	72910.931648
19.66976	64625.598506
21.90496	58031.149679
24.36368	52174.795124
26.8224	47392.105571
29.50464	43083.732338
31.2927	40621.934588
31.2928	0
)
)

[istvanek]

NickonWheels, on 08 February 2020 - 09:15 AM, said:

Erick, according to Wikipedia the GP7/9 has 65000lbf starting tractive effort so their traction curves looks like following

Hi,
you have calculated this curves or you have prototypical data?

Artur

[NickonWheels]

istvanek, on 08 February 2020 - 09:51 AM, said:

Hi,
you have calculated this curves or you have prototypical data?

Artur

I calculated these with a program I developed for this purpose, it can also calculate fuel consumption and power settings.

[istvanek]

NickonWheels, on 08 February 2020 - 10:59 AM, said:

I calculated these with a program I developed for this purpose, it can also calculate fuel consumption and power settings.

That's interesting. What data do you use as an input data for yours calculations? Starting tractive effort, max power to rail, anything else? How you program determine output tractive effort curve shape for each notch position (prime mover rpm value)?

[NickonWheels]

istvanek, on 08 February 2020 - 12:29 PM, said:

That's interesting. What data do you use as an input data for yours calculations? Starting tractive effort, max power to rail, anything else? How you program determine output tractive effort curve shape for each notch position (prime mover rpm value)?

Yes, starting tractive effort, maximum engine power, min & max RPM and some data about the engine itself (for other calculations); the positioning of the notches is done by the revelation of idle rpm and maximum rpm, including power calculation for each notch. And this is not only possible with 8 notches, it works with any number of notches higher than 0, though train operations would fell quite bumpy whan having only idle and full power... Wheelslip not mentioning.

[istvanek]

NickonWheels, on 08 February 2020 - 01:15 PM, said:

Yes, starting tractive effort, maximum engine power, min & max RPM and some data about the engine itself (for other calculations); the positioning of the notches is done by the revelation of idle rpm and maximum rpm, including power calculation for each notch. And this is not only possible with 8 notches, it works with any number of notches higher than 0, though train operations would fell quite bumpy whan having only idle and full power... Wheelslip not mentioning.

Cool, this is what actually OR is doing with basic (without TE curves) eng file configuration. It constructs some kind of generic traction effort output basing on provided input data and physical calculations. And I believe that it is actually the thing Peter is working on now. Maybe you should cooperate :)

Artur