V5.10 OR Physics files

[plainsman]

A major breakthrough in Open Rails specific physics. !!!
Joe Realmuto has created a new utility that will dramatically improve physics performance in Open Rails Simulator. This utility creates data that OR can exploit for more realistic performance. We can now model power limiting, defined power curves for each throttle position, and realistic tractive effort on heavy freight locomotives. I just uploaded a set of three files which will simply slip into the folder to replace the old MSTS files in two C33-7 and one C36-7 Burlington Northern Shop Rebuilds. NO CUT and Paste on these!! Just replace the old files (make a back up just in case!). You still need to use Shift plus X for sanding, but now you can climb those steep grades at realistic speeds and tractive effort.
PLEASE, comment as to the way these files feel in OR!! The feedback will really help, especially if there is an issue or problem we overlooked? I tested the files on Crawford Hill, and I went up with four C33-7 units pulling 105 loaded Bethgons, with a set of pushers trailing, at 10.2 mph. You still need Shift plus X to maintain sanding below 20 mph.
Excited!!!

[seagoon]

Good stuff, Bob!
I look forward to seeing the files appear in the library.

Might I be so bold as to suggest that, for those of us who may not have the locos for which you are making OR Dynamics (my copyright but you can use it if you wish ), you direct us to the appropriate loco file by mentioning the file name, if possible?

Cheers!
Bruce

[plainsman]

Hi Bruce,
The three files are:
c337bnsf.zip
bn5569u.zip
bnc367.zip
they are also listed in the readme file on V5.10OR Physics. If I remember correctly, the c337bnsf file has some errors in the old msts file with some units incorrect. All that gets repaired in these files. BTW, I managed to break a coupler with these files in testing. I set the train up on a steep grade, with the 4 locomotives over the crest of the hill, and released the brakes. When the train started rolling backwards, I applied some throttle and bang, broken coupler, the four locomotives suddenly were pulling easily with no train behind them. Most reasonable folks wouldn't try that and keep their job, so they don't break if they are not supposed to break. With the indestructible couplers used in MSTS, this will add a bit of new skill to the simulator, as you can't abuse the train anymore.
I am particularly fond of these units, as they were really often seen on the unit coal trains that ran through Hazard Nebraska, on their way from Crawford to Ravenna. The distinctive red numberboards set them apart. I moved to Nebraska in 1993, just as these were at their peak of operational effectiveness. They were very common until late 1995, as the comfort cabs started leading. It was not uncommon to see the C36-7 trailing a pair of SD60M on a merchandise freight through Minden Nebraska, even until 1997. About that time, these got moved out into pusher duty in the Rockies. A few made it down to the Ozarks, and for some reason were often seen on merchandise freights right through the end of the decade, in Branson Missouri. I think the slow speed of these trains made them useful, as the high horsepower Dash 9s were wasted on these low priority trains.
BTW, the SD60 Oakway units were very commonly seen with these units, but were inevitably trailing, as they seemed to have a problem with their front trucks in the lead.

[Gary54]

Hi Bob,

This is really exciting news. I have been using your ES44AC files on the NS East River route. I am running an empty coal train that includes 144 empty bethgons being pulled by an ES44AC followed by a D9-44CW (based on an observed consist on that route). The ruling grade on the westbound approach to Bluefield is 1.2% and I am sanding at and below 14 mph (dry track). No problems to speak of yet.

One question - should I be sanding at less than 14 mph if I'm not getting any wheel slip warnings? My intuition would be that given the potential damage to rails caused by sanding, automatic sanding would engage only when needed.

Gary

[plainsman]

That is true Gary, but if unstable wheelslip begins in OR, you never really recover fully, so you have to sand before it starts. If you are running without any wheelslip warnings without sand, you are OK. It seems to me, by the time i get the warning and react, I am already behind. I just look at shift X as turning on autosanding. In my mind, my virtual sand isn't running if not needed.?.

[seagoon]

Hi Bruce,
The three files are:
c337bnsf.zip
bn5569u.zip
bnc367.zip
they are also listed in the readme file on V5.10OR Physics. .........

Thanks, Bob.
Much obliged for that.
And also thank you for the additional info on the trains through that area.

Many moons ago - before the MSTS "Crawford Hill" - I did that route for Trainz (and then updated it for Tz2012 three years back).
It was an interesting and enjoyable experience. Researching the route was fascinating.

All the best,
Bruce

[Gary54]

Hi Bob,

I agree - the sand isn't running if it's not needed. In running the empty coal train that I mentioned yesterday, I was able to start without trouble (wheelslip warning) on low grades. However, eventually I started sanding and throttled down a notch and things ran without problems.

I have a questiuon regarding Sanding values used in the engines files of non-AC engines. The ORTS AC physics file assigns Sanding values of 22 mph. What value should be used on DC units? While I've been upgrading all of the AC units using your ORTS physics, the only changes I have been making to DC units includes the ORTS adhesion line and the modification of the Maxpower value. My impression was that the higher Sanding value used in the ORTS AC physics reflected the auto-sanding capabilities of the unit. Your description of the loaded BN loaded coal train on Crawford Hill suggests that sanding can begin at higher speeds.

Thanks very much,

Gary

[seagoon]

Well, whilst we are on the subject of sanding, here's an interesting thing which I've never seen before tonight: a warning message popped up, when I pressed 'X'...............

"Sanding Blocked".

Never seen that before!

Repeated presses of 'X' had no effect but after several minutes, when I tried again, sanding was successful.

And then it became blocked once again.

Is this something that the OR coders have snuck in or......?????

[cn bala]

Are you comfortable to change the line in eng file in WordPad? If yes, then go down to see the word with " Sanding " and change from 5MPH or other number to 50MPH. Then you are good to go with sanding in simulation.

John

[baldwin]

Sanding is blocked if the speed is above the sanding limit set in the eng file

[plainsman]

The sanding blocked question was already answered, but the suggestion to increase sanding speed, I would think 30 mph would be plenty, and even then that would only be needed with frosty rail. In North America, even frosty rail isn't quite the issue it is in Europe, where the guys writing the code are experienced. By the time you have 3 units with six axles weighing 415,000 pounds each unit, generating friction on the rail, it isn't as frosty on those back axles. OR has tended to be a bit emphasized in wheelslip, and it isn't as much of a problem over here (and also because of auto-sanding and other features we see more here than maybe in Europe)? At any rate, you need sand in OR much more than you did in MSTS. When we get auto-sanding everything will make a lot more sense, and we can take that line out or move it to the maximum speed, for units that have auto-sanding, but that is in the future.
I wanted to also explain, the first AC files were very different than what I am using now. Part of that comes from discussion I have had with Joe Realmuto about how best to write the adhesion line. For example, for an ES44AC, I wrote the line:
ORTSadhesion ( ORTSCurtius_Kniffler ( 9.2 41.8 0.173 0.7 ) )
now I am using:
ORTSadhesion ( ORTSCurtius_Kniffler ( 24.5 73.8 0.160 0.7 ) )
What we are doing now differently, on all future freight files the last two values will be constants, 0.160 and 0.7. The reason for this is that the value 0.160 only really becomes significant at very high speeds, higher than any freight is going to reach, so we can set that value to 0.160, and solve for the other two values. When you do that, we had to increase the value of both A & B terms to allow enough adhesion at minimum continuous speed, to reach the continuous tractive effort rating of the locomotive. I was waiting to rerelease the files, on getting Joe's power curve utility working under all versions of Excel. Joe wrote it under an older version and I have 2013, which does all the calculations just like Joe's, but won't create the table to paste into the file. I don't want to have to send a bunch of files to Joe to have him do a cut and paste of the table, so I was waiting for that issue to get resolved before putting out a set of V5.10OR AC files. Further, now that we are using power curves, we can enter full max power in the file, and the program will use appropriate transmission efficiency.
Another thing that is now very different, OR uses a different way to define the coupler action than MSTS. In discussion with the folks over at Elvas, I learned a few things we need to do differently. The new coupler line in the AC files would look like:
Coupling (
Type ( Automatic )
Spring (
Stiffness ( 7.5e3N/m 4.9e6N/m )
Damping ( 9.4e5N/m/s 3.5e6N/m/s )
Break ( 2.32e6N 2.41e6N )
r0 ( 0cm 11cm )
)

Velocity ( 0.14m/s )
)
Note a dramatic change in the r0 line, in OR that needs to always be 0. I also found some information that coupler strengths were increased on most AC units in 2014 to higher strength, so this line represents the "2014 standard". Since OR does not use the buffer data at all, I took that out.
Once Joe gets ready to put his spreadsheet utility out, I will redo the AC files to V5.10. Further down the road, we know that the dynamic braking action in OR isn't working correctly with these files. There was a bug in MSTS that required all the files have a very different way to write the performance data, so we will have to completely redo the dynamic section. Joe and I are working toward that goal down the road. The dynamics currently generate too much power at higher speeds. When we did the original dynamic package for MSTS, Joe and I had 12-20 actual dynamic curves from which we based each model (EMD works differently than GE, and some EMD are standard and others have an extended range). Then the power depends on the traction motor and number of powered axles for each unit. The V4.7 SD files have all SD40 with standard, and SD40-2 with extended range. The dynamic braking definition for an SD40 will be the same for an SD39 or an SD45, since the traction motors are the same. It will take a little work to get dynamics working as they should in OR.
BTW, many DC files will not need the complicated math process to determine the adhesion line as the conventional CK values allow enough room to reach their continuous tractive effort.

[apco25]

Bob, awesome work and news here. Will, at some point this become a drop in for RouteRiter like the older files? I have too much to be updating manually

[seagoon]

The sanding blocked question was already answered, ......... (followed by lots of very interesting info!)

Once again, Bob, my thanks for such an in-depth explanation - and also to the two preceding posts which explained why I was seeing that message.
The locos in question were, in fact, the C33 and C36, but your original models, not with the new dynamics.

So I am now downloading (zip!....there it is already) the new files and will be interested in seeing what happens now when I climb Crawford Hill with 100 laden cars in tow!

Bruce

[crstagg]

?????????? TWO files
Open Rails - Open Rails Misc.Open Rails 5.10OR Burlington Shop Rebuild .eng Files
[ Download | View ]
Name: bnc33andc36.zip
Size: 40,818 Date: 04-13-2015 Downloads: 38



Open Rails 5.10OR Burlington Shop Rebuild .eng Files. A new state of the art (4-11-2015) set of replacement .eng files to get realistic performance from the Burlington Alliance Shop Rebuilds, C33-7 and C36-7 in Open Rails. Modifications to .eng files by Joe Realmuto and Bob Boudoin.





And
Open Rails - Open Rails Misc.Open RAils 5.10OR Burlington Shop Rebuild .eng Files
[ Download | View ]
Name: v5_10orc33_c36physics.zip
Size: 40,473 Date: 04-13-2015 Downloads: 24




Open RAils 5.10OR Burlington Shop Rebuild .eng Files. A new state of the art (4-11-2015) set of replacement .eng files to get realistic performance from the Burlington Alliance Shop Rebuilds, C33-7 and C36-7 in Open Rails. Modifications to .eng files by Joe Realmuto and Bob Boudoin.



Same date. Seem to contain the same files.

[plainsman]

When I uploaded the files, the first time I got an error message that the upload failed?? I thought maybe the underscores in the file name were problematic, so I uploaded without them and got a message upload successful. Only one file (the one without underscores) should be in the library. I am sorry for the confusion, it told me it didn't work???