[NickonWheels]

Hmm... I do understand ORTS diesel engine parameters and I´m indeed able to figure out all the necessary values in them; I just tried what happens when MaxDieselLevel is missing... Weird outcome, don´t know where the 5000 comes from, but that´s what this line is for.

You maybe meant to put MaxDieselLevel into the include file, which I would never do because for example not all SD40-2s have the same fuel capacity. The other lines like smoke magnitude can be deleted though...

[Lamplighter]

I don't attach much importance to include files. The .eng and .wag settings files are plain text. They take up no space. For better clarity I use all parameters together.

[steamer_ctn]

NickonWheels, on 18 December 2019 - 03:33 AM, said:

The only files I can offer you are about the London & Port Stanley diesels (which are the same files in content), others were modified with my huge collection of include files. Gerry made 176 files while I combined some and made new ones like the RSC-24 the new model by Pual Charland, having 164 files...
CANG12v1.eng

I have added some code to the latest unstable version to address this problem (I think). Basically it was an issue with the power and force values not being "correctly" initialised for the locomotive. Hopefully it should now work in the unstable version.

I think that I have identified some other issues with diesel configurations that I want to investigate further once I have some test models configured by some testers who are assisting me.

In regard to INC file, they should be carefully used, as there is a potential issue when BASIC and ADVANCED configurations are used within the ENG files. See this post for the relevant comments on data sequencing in OR. Incorrect sequencing of mixed configurations may cause errors.

[NickonWheels]

Thanks, Peter

Driving diesels with engine tab and traction curves for a while now I witnessed that with such engines the file MaxVelocity does´nt work properly anymore (not just in X1.3.1-107 version). My CN Ruel Sub engines got at least 115mph but MaxVelocity says 70mph as with most rather modern US diesels. There must be some code bug causing the traction curves to override the fuction of this crucial line.

Yes I tried and observed many ORTS shortcomings, which many of you might never had noticed before.
Nick

[steamer_ctn]

NickonWheels, on 20 December 2019 - 02:10 AM, said:

Driving diesels with engine tab and traction curves for a while now I witnessed that with such engines the file MaxVelocity does´nt work properly anymore (not just in X1.3.1-107 version). My CN Ruel Sub engines got at least 115mph but MaxVelocity says 70mph as with most rather modern US diesels. There must be some code bug causing the traction curves to override the fuction of this crucial line.

Yes I tried and observed many ORTS shortcomings, which many of you might never had noticed before.

As far as I can see in the code, MaxVelocity sets the motive force to zero for locomotives without traction curves defined. However I don't believe that this is the case in real life.

A properly defined traction curve would take the max velocity into account.

As suggested I won't be doing any more significant code changes until I have some well defined test models available to me that I can use to test performances against well defined test reports.

Thanks

[edwardk]

Are we certain that MaxVelocity() is being zeroed out? In the code, MaxVelocity() is read into a new variable called MaxSpeedMps. I was unable to locate a line that would zero out MaxSpeedMps. It may be possible that a new set of calculations is not using MaxSpeedMps.

[edwardk]

Check this out to see if this is the reason why the MaxVelocity() source is not working. Keep in mind that MaxSpeedMps is now representing MaxVelocity()

Peter, I know you saw this as well, but in my mind the two if statements using MaxSpeedMps are contradicting each other. You notice the original statement that is commented out where maxForceN is set to 0, but this statement is now used after a new calculation.

if (TractiveForceCurves == null)
                {
                    float maxForceN = MaxForceN * t * (1 - PowerReduction);
                    float maxPowerW = MaxPowerW * t * t * (1 - PowerReduction);

                    if (maxForceN * AbsWheelSpeedMpS > maxPowerW)
                        maxForceN = maxPowerW / AbsWheelSpeedMpS;
                    //if (AbsSpeedMpS > MaxSpeedMpS)
                    //    maxForceN = 0;
                    if (AbsSpeedMpS > MaxSpeedMpS - 0.05f)
                        maxForceN = 20 * (MaxSpeedMpS - AbsSpeedMpS) * maxForceN;
                    if (AbsSpeedMpS > (MaxSpeedMpS))
                        maxForceN = 0;
                    MotiveForceN = maxForceN;
                }

[steamer_ctn]

edwardk, on 21 December 2019 - 10:18 AM, said:

Peter, I know you saw this as well, but in my mind the two if statements using MaxSpeedMps are contradicting each other. You notice the original statement that is commented out where maxForceN is set to 0, but this statement is now used after a new calculation.

That is why I made the comment that I thought Motive Force was zeroed once the MaxVelocity had been exceeded. However it would need to be tested and confirmed.

[steamer_ctn]

As suggested earlier on in this thread, I wish to investigate aspects of the diesel locomotive code in some more detail. To do this I have created a test model, for comparison of code change results.

The locomotive selected is a BR unit which was the subject of a detailed test report, and this can be used to accurately configure the model, as well as compare the OR outcomes.

The model consists of a locomotive ( BR D16/2 #10203 ) and a set of cars ( Mark1 ), and the locomotive is set up with two configurations, ADVANCED and BASIC. For a general description of the difference between BASIC and ADVANCED configurations, refer to this page. As a demonstration, I have configured the BASIC model as a minimalistic version which only has enough parameters to get the model running. The ADVANCED version has all the relevant power/force tables modeled from the test report. (Note, these files should be considered a work in progress)

As part of the testing, it will be interesting to see the difference in performance between the BASIC and ADVANCED versions, and thus it is suggested that anybody wishing to run any tests should read the referenced test report to get an understanding of the locomotive and its performance in real life. One test might be to use the CTN test route, and run the train up the 1 in 80 gradient, based upon graph 11 in the report, a steady state speed of approx 30 mph should be achievable with a load of 286 tons uk.

This model only has a single prime mover, so I am considering also configuring a unit which also has a test report, and has two prime movers (BR Deltic) to see how it performs in OR.

[Gehe]

Hi All,

beside the issue discussed above I found a changed behaviour related to diesel performance in the newest OR version
27th December, X1.3.1-108-g85be7602 which I would like to add to this topic.

For diesel locos not using tractive force tables the motive force and power are derived from the max power and max force statements in the eng files.
In this new version it looks like that there is a new kind of power reduction. If you have 100% throttle you get just 78.4% of the max power to the wheels.
You can see this factor of 78.4% also in the extended F5 HUD (locomotive view) as a load factor.

I would like to know what is reason behind this new behaviour? There was no change in my eng files.

I believe this has nothing to do with the reduction factor of 0.98 which is used in OR generally for diesels;
also the model used for warming up of the traction motors should not be of any significant effect here since the locos were "cold".


Best Regards
Gehe