[steamer_ctn]

PerryPlatypus, on 10 January 2020 - 11:02 AM, said:

By the way, if you want another issue to get angry about, I think OR's handling of adhesion in snow/rain with the "Advanced Adhesion Model" is a problem that causes even more dramatic variations from reality, but unfortunately it too is a topic that is extremely hard to find good scholarly data on, especially related to modern heavy-haul freight operations... The problem is such that on an upcoming payware route release, we are going to have to stipulate to users that for snow and rain activities to work, they must use the default adhesion correction factor of 135% (or whatever it is), because using the "realistic" correction factor of 100% makes it physically impossible to run prototypical (certain tonnage and locomotives) heavy trains up mountain grades in the snow...

Can you provide some more detail on the trains that you are trying to run up the hill, and what is happening?

Locomotive types, tonnage, grade, etc?

Thanks

[PerryPlatypus]

steamer_ctn, on 11 January 2020 - 12:13 PM, said:

Can you provide some more detail on the trains that you are trying to run up the hill, and what is happening?

Locomotive types, tonnage, grade, etc?

Thanks

Hi Peter,

Feel free to PM me or start a separate thread on the below if we don't want to pollute this thread with the discussion.

An example consist below, which can go up the steady 2.2% grade of Mullan Pass in real life at a steady 10 to 12 MPH during rain or snowfall.

Consist: A 125-car coal train configured as follows: 3 x ES44AC, 78 loaded coal cars (286,000 lbs each), 4 x SD70ACe mid-train (I have seen either 4 or 5 mid-train units in snow), 47 more loaded coal cars (286,000 lbs each), 1 x ES44AC on rear.

When I try to run this consist in OR during snowfall, it slips like crazy, cannot keep moving (quickly stalls out if I get a run at the hill at the bottom of the grade). I believe we are using realistic Curtius Kniffler adhesion numbers, because in clear weather we get spot-on starting and "continuous" tractive effort and very realistic speed compared to reality, but I'm curious to see the results you can get. Getting going from a stop on the grade is essentially impossible, and even keeping moving if you get a run at the hill seems impossible for me. Again, using 100% correction factor for adhesion, and adhesion proportional to snow/rain/fog turned ON.

[steamer_ctn]

Hi Sean,


Thanks I will PM you.

[NickonWheels]

Updates on the subject...

I deleted ORTSFriction and am currently shifting everything done so far into the usual MSTSWagon file. From the first look I think that the old parts of the code (meaning the equation with ORTSBearingType) would still work outside of the new part in making, hopefully it then works too as it requires more lines in the wagon section to work; for the moment these being the three Davis lines plus ORTSStandstillFriction and ORTSMergeSpeed. I will get further onto describing this when I got it done for the moment.

[NickonWheels]

After much reshuffling it still does not work, ORTS always reverts to the old equation. Is there anyone who can describe to me what is wrong here?

Maybe it works when kicking out the current code section but then the addition of mine would not be eligable for anything useful...

[NickonWheels]

Weird!
I tested the code uploaded here with the Ruel Sub, ES44s and the built-in graincars and... Something strange is going on. The engines still work as they use the old equation, even the third one I converted with the new lines (but does not work for some reason); the wicked thing is that the graincars using the three Davis lines and bearing type (like the first two diesels) now show zero friction at all times! Though I have not changed anything in the old section...

It´s fair to say that ORTS looks more and more hopeless from the 'coding and actually make it work as intended' point of view. You can´t imagine how frustrating this is...

[Csantucci]

Hi Nick,
I had a short look at your code. You might have made an error in this line

if (IsDavisFriction || IsORTSFriction == false)    // If Davis parameters are not defined in WAG file, then use default methods

In the original code there was

            if (IsDavisFriction == false)    // If Davis parameters are not defined in WAG file, then use default methods

Are you sure that your if clause is correct? Your if clause becomes true if IsDavisFriction is true or if IsORTSFriction is false. Maybe you wanted it true if IsDavisFriction is false or IsIRTSFriction is false? In such case your clause must be

if (IsDavisFriction == false || IsORTSFriction == false)    // If Davis parameters are not defined in WAG file, then use default methods

or, in a more compact way

if (!IsDavisFriction || !IsORTSFriction)    // If Davis parameters are not defined in WAG file, then use default methods

[NickonWheels]

if ( !IsDavisFriction|| !IsORTSFriction )

This is meant to use the old MSTS friction setting if DavisFriction and ORTSFriction are both not in use. The real problem is that DavisFriction (the older part partly using ORTSBearingType) is still used instead of ORTSFriction even when the two new lines are present in the wagon section of the .eng/wag file. For unknown reason the new chunkof code is bypassed as ORTS seemingly does not know the new lines although they are defined just as the lines used in the current model.

// wag file data
        public string MainShapeFileName;
        public string FreightShapeFileName;
        public float FreightAnimMaxLevelM;
        public float FreightAnimMinLevelM;
        public float FreightAnimFlag = 1;   // if absent or >= 0 causes the freightanim to drop in tenders
        public string Cab3DShapeFileName; // 3DCab view shape file name
        public string InteriorShapeFileName; // passenger view shape file name
        public string MainSoundFileName;
        public string InteriorSoundFileName;
        public string Cab3DSoundFileName;
        public float ExternalSoundPassThruPercent = -1;
        public float WheelRadiusM = 1;          // provide some defaults in case it's missing from the wag
        protected float StaticFrictionFactorN;    // factor to multiply friction by to determine static or starting friction - will vary depending upon whether roller or friction bearing
        float FrictionLowSpeedN; // Davis low speed value 0 - 5 mph
        float FrictionBelowMergeSpeedN; // Davis low speed value for defined speed
        public float Friction0N;        // static friction
        protected float Friction5N;               // Friction at 5mph
        public float StandstillFrictionN;
        public float MergeSpeedFrictionN;
        public float MergeSpeedMpS;
        public float DavisAN;           // davis equation constant
        public float DavisBNSpM;        // davis equation constant for speed
        public float DavisCNSSpMM;      // davis equation constant for speed squared
        public float DavisDragConstant; // Drag coefficient for wagon
        public float WagonFrontalAreaM2; // Frontal area of wagon
        public float TrailLocoResistanceFactor; // Factor to reduce base and wind resistance if locomotive is not leading - based upon original Davis drag coefficients

[Csantucci]

Sorry, but I don't follow you. What do you want that the mentioned if clause does?

[NickonWheels]

Quote

What do you want that the mentioned if clause does?

It´s supposed that ORTS goes back to the MSTS friction section if neither of ORTSDavis_A, ORTSDavis_B, ORTSDavis_C, ORTSBearingType, ORTSStandstillFriction or ORTSMergeSpeed is used in the wagon section.