[copperpen]

Far as I am aware, the Numwheels is currently only valid for steam locomotive adhesion. One thing that is not clear however is what this actually is, the number of driven wheels, or the number of driven axles.

[ATW]

I think someone should try a long heavy train with a diesel where if it starts slipping at high Throttle positions like Run 8 looking at Force Information.... next with that same diesel leader go into eng file changing Num Wheels to 0 an repeat the process watching a change.

[Hobo]

Doesn't the Numwheels entry in steam or diesel means axles as any documentation out there on MSTS states . We've used that quite successfully for steam and diesel for 15 years so why would it be doubtful now . Is Or different from MSTS in this respect , because the item on test units at Newcastle uses those parameters on their 6 driven axle diesel test unit . Has something been changed since then ?

[copperpen]

In MSTS the NumWheels was meant to be either wheels or axles, but in fact was neither. The one on the engine section was a divisor for the adhesion line and the one in the wagon section was supposed to do the same for braking, but never did anything except act as another divisor for the engine adhesion. All I am seeking is wheels or axles for that figure in OR.

[steamer_ctn]

copperpen, on 11 June 2016 - 11:26 AM, said:

In MSTS the NumWheels was meant to be either wheels or axles, but in fact was neither. The one on the engine section was a divisor for the adhesion line and the one in the wagon section was supposed to do the same for braking, but never did anything except act as another divisor for the engine adhesion. All I am seeking is wheels or axles for that figure in OR.

As suggested the NumWheels parameter has negligible effect on the OR diesel adhesion model, and it is used in the steam model.

As has also been suggested it indicates the number of axles, not the number of wheels.

[copperpen]

Thanks for the clarification Peter.

[Kazareh]

disc, on 28 April 2016 - 08:25 AM, said:

Advanced adhesion simulation has problems, but the developer of that code, left the project more than one year ago, and it seems noone understands the math in axle.cs.

Truth be told, maybe you guys should set a standard with your coders that the code they write -has- to be more or less universally understasndable? I keep hearing that you guys 'Don't understand how this string of code works', and as an open-source sim that rather defeats the purpose, not to mention causes issues such as this.. I'd rather the size of the program be a bit beefier and prevent issues like this, honestly...

[copperpen]

I believe we are now working towards that standard, but the adhesion code is a couple of years old now. Steps are being made in the right direction, but it all takes time. Steam is fairly well advanced and it should be possible to take that work and apply it to diesels and electrics once we know it works properly.

[steamer_ctn]

The current advanced adhesion model uses the full mass of the locomotive as the "adhesive weight", which is not always correct.

#3561 now allows for the specification of the locomotive drive wheel weight to be defined in the engine section of the ENG file.

The relevant statement is:

ORTSDriveWheelWeight ( 109.5t-uk  ) Comment (Weight on all drive wheels)

The test model from earlier in the thread has been updated to allow for this change.

[ATW]

I like this new addition as your test unit is using about %82 of it's weight for the drive wheel weight. But if all the axles were powered it would maybe be about %92?

How is Drive Wheel Weight really calculated vs max Tractive Effort vs number of Axles?