Is anyone writing OR format .eng files?

[Bananarama]

Best news in quite a while.

Models are done, but I'm still tinkering with mapping. These are pretty heavy units at 41k or so (primary LOD), so I'm unsure how they'll come together in Gmax for final export (they're in 3DS Max ATM).

Just trying to get my head around the 3D cab definitions, so that puts me in the same basic boat as Bob with his physics.

[baldwin]

Bob

I have been looking at the OR code and find that the eng file information is read by 5 different files. Adhesion looks to be either MSTS, modified, or Curtius-Kniffler. If ORTSCurtiusKniffler lines are present these will be used instead of the old MSTS lines. Same applies to friction. If ORTSDavis lines are present these will be used instead of the MSTS friction statement. Far as these traction curves go, I have not used them much, but cannot see much difference between using them and not using them.

The rest of the eng file is pretty much used as is where required. However, in OR couplers can use real world data as the "Cutbank Syndrome" does not exist there.

[plainsman]

Hi Baldwin,
OK, so if I want to input Curtius-Kniffler data into the program, where for example do I input {adhesion coefficient max dry} = (7.56/(v+44))+0.163? Also, is there any setting for automated sanding. Most modern wheelslip systems use auto sanding.

[plainsman]

Hi UP Thunder,
I wanted to explain why I appeared to ignore the SD70M data you posted. As you set up the curves, it is essentially an exponential throttle. EMD turbo 645 and newer turbo units all have a mechanical boost through notch 5, then switch to exhaust driven turbo in Notch 6. The power curve in all of these is NOT exponential, the slope is less steep up through notch 5, a swail at notch 6 and a steep increase in 7 and 8. The SD70M unlike the SD60 has a computer controlled spinup feature in notch 6, so for a brief time the throttle over advances in notch 6 until the turbo boost spins up, where it drops back down. This makes the SD70M power curve model extremely complicated.

[baldwin]

According to the manual section 8.1.3 dealing with diesel adhesion the parameter is added as ORTSadhesion ( ORTSCurtius_Kniffler ( A B C D) ) where A B and C are the adhesion coefficients and D is always 0.7.

For example ORTSadhesion ( ORTSCurtius_Kniffler ( 7.5 44 0.161 0.7 ) ) and it is placed in the Wagon section of the file.

The manual gives a bit more detail as to how these figures are used.

Automated sanding is not implemented yet. We have lost Matej to his real world projects for the foreseeable future as far as coding goes and we do not yet have anyone to take up the slack in the diesel physics department, particularly adhesion, so we have to work with what we have for now.