40Ft. TankCar Physics For Open Rails?

[marklester01]

I've found 30', recently 48'( really needed it,lol ), think I can find 57' ones, & will be able to do the 65' thanks to all those SLI Upgrade Kits, but what about 40' ?

[CSRX]

Tonnage ratings wise, depends on the car load itself.
majority of the time, the clay/limestone Slurry tanks are 30 tons empty, and have rigid couplers with very little slack action like you'd see with a cushion drawbar car. Loaded they can range from 125 tons to 143 tons. Tonnage ratings I base on the railroad I deal with, for example, VTR is restricted to 131 tons for their loaded cars (263k rating), meanwhile somewhere along the BNSF, I bump the load weight to 143 tons (286k capacity).


There are some other changes I make as well, but at the moment can't really share them, as I am not in front of my computer, to be able to open the wagon file and dive deeper.

[marklester01]

Thanks Shawn, I didn't think 40-48 would really matter, for The only 48 is on a Clay-Slurry one*. But, so far The only 40' Ones I've got available are Sulf.Acid.( if that makes any diff like Molten Sulf.etc. ).

[CSRX]

Thanks Shawn, I didn't think 40-48 would really matter, for The only 48 is on a Clay-Slurry one*. But, so far The only 40' Ones I've got available are Sulf.Acid.( if that makes any diff like Molten Sulf.etc. ).

Those two products can be just as heavy, and sloshy. Kind of wish that was something that we could get into ORTS. No matter how much brake you put in those cars, the liquid will rock that car for a bit. Super annoying actually..

acid tanks are typically between 28-32 tons empty, and 125-131 loaded. I haven't seen any of them at the 143 rating yet, and probably won't.
Same with the Molten Sulfur tanks.

I should release a file that has modern (2020-2023) based tonnage ratings for specific cars, but I'd be told they are wrong, so I don't bother..
even though, mind you, all are based off actual tonnage ratings I have from work, from the car waybills and train consist papers.

I got a wide range of them for autoracks, boxcars of different types and loads, log flats, centerbeams, tanks, chip cars, well cars, containers, etc.

[marklester01]

I'd love for you to do that! I get what you're saying( You Work for The Railroad though? ). How's Those Ton Numbers=/adjust to ORTS for The Tank car as a whole,lol?

[CSRX]

I've set up a notepad with US tons converted to metric tons which ORTS prefers. Done a few trial and errors along the way. Anyways..

Empty: for 30 tons I use : 27.2155
Loaded: for 123 tons I use: 111.5837 on some tanks such as Acid or Sulpher. Clay/Limestone I will normally use: 117.934 which equals to 130.


These all work, and will show appropriately in ORTS under the F5 info as 30 tons, 123 tons and 130 tons.

Like I said, I got a wide variety of tonnage ratings that I need to eventually label for various car types, and release it so others can have accurate tonnage ratings as well. Especially for Autoracks, Log Cars, Chip Cars, etc.

[marklester01]

Ok, so that was just for Clay-Slurry( on The SLI-TS ORTS Upgrades ), & yours ( IF others would so choose to use ) would be more up-to-date,..? Apparently it just matters on the .Mt-.LD Ratio( so to speak ), & The Adh,..wouldn't need adjusting? 40-48 maybe only 8feet difference, but apparently It's ALOT to consider. I'll be standing by. Where do those numbers go? ORTSDavis_A ( 1271.30 )
ORTSDavis_B ( 21.2244 )
ORTSDavis_C ( 1.461438 ) is what I copied for one from The Lone Clay-Slurry "Updater" On The CP_Mactier*.

[CSRX]

Adhesion I think I updated too, cannot remember.
don't know what those DavisA numbers are. I don't use those at all. I keep things simple under the weight section of the cars.

Edit:
Okay so diving into one of my tank cars used for clay slurry.

Loaded:
"Mass ( 127t )"
this equals out to around 140 total tons. Though, this is not the case for the specific car, so I need to change that as max capacity of the car is actually 263k or 131 tons.
Adhesion has been left the same as it originally came in from the CP MacTier original set.
Due note, I absolutely do not use any of these "updated" files you are referring to.

For the Empty car:
"Mass ( 27.2155t ) " which equals out to about 30 US tons.


If you downloaded any of my recent files, you will find that for gasoline/diesel fuel/fuel oil tanks, I used a loaded weight of "Mass ( 111.5837t )" which equals out to 123 tons. This has been pretty normal for the consist sheets I get at work for most, if not all fuel oil, gasoline, diesel fuel, and even ethanol tank cars, though take note that some ethanol cars can be up to as much as 135 tons.


The loaded Asphalt tankcars I did, are at a 127t mass, which equals to their typical 140 tons loaded capacity.

I've recently had noted that some of the cars that got updated to whatever physics someone chose to use, had to be deleted as it rendered the cars unrealistic and broken in the TSRE Consist Editor as well as ORTS. Since then, I have changed some to better match the recent car data physics from Trainsimulations, as they are much more spot on than these "physic updates".

However, also note, using the physics from Trainsimulations, with the updated tonnage ratings in the mass section, still holds the most realistic operations of railcars between sim and reality, this of course includes changes needed for the correct knuckle types on most rail cars, and derail factors in place. My recent freight packs actually reflect that, but keep in mind they work best in ORTS 1.5.1. Older versions and the MG versions of ORTS tend to make things funky and always showing cars either derailed or broken knuckles.

[pschlik]

Going to give my 2 cents here since I've been editing wagon files for a while now...I would greatly recommend setting the mass directly as US tons instead of needlessly converting to metric. Unit conversions lead to mistakes, and also to funky numbers with too many decimal places. For a 263K car, mass can be set as

mass ( 263000lb )

or

mass ( 131.5t-us )

If you enter the mass in pounds you can directly input the empty weight based on the texture of the train car (LT WT 60000 printed on a car means it weighs 60000 pounds empty, no need to convert that to anything else). Like Shawn has pointed out, loaded weights vary but the boring option is to add the LT WT and LD LMT weights, just assuming the car is completely full.

The Davis numbers all relate to drag force, which you'll want to set correctly to have a reasonable driving experience. The Davis_A and Davis_B numbers change with the car weight (Davis_C is aerodynamic drag, which doesn't need to be changed as weight changes) and can be calculated with the FCalc utility available on the file library here-it's fcalc.zip. Or just copy the numbers from a similar type of train car with a similar weight.

As for adhesion I don't think there's any reason to add adhesion to a wagon as OpenRails sets a default level of adhesion for all non-locomotives.

[marklester01]

I meant The Davis Thing by adhesion.

[CSRX]

I will say, I have seen several cars with the direct US tons, and ORTS doesn't render them properly from what I've experienced. If you put 140t-us, it will be an outrageous number in the sim. I did notice that with a lot of the MRL Mullan Pass cars, and I had to go through and fix them according with the "needlessly" converted numbers for them to act appropriately.




Here is a good example of that..

Rolling Stock Consist is the Mullan Pass BN 50 foot F plate boxcar, NVLW BR 73 foot centerbeam, and an unreleased NVLW clay slurry tank car.

You'll notice the tonnage ratings on the screen...
Boxcar at 151 tons is way over the limit. In the file itself it shows a mass of "141t-us"
Centerbeam shows 140 tons, in the file itself I have the mass set up as "127.006t"
tankcar shows 140 tons, in the file itself I have it set as "127t "

However I have seen other cars set up with a mass of "141t-us" and it loads fine. So it's a odd fluke where some times it works, sometimes it doesn't. It's why I stick with the metric tons conversion. It works best in my opinion, and I've been working with wagon and engine files since 2004, but didn't get into the fixing of tonnage ratings and other things until 2015-2016.

[marklester01]

See, Math's NOT My Strong-Point,lol! Yes, I've indeed seen your ORTS_Related .Wag Files in The Past*. Those "updater" Files do update The Older rolling MSTS Rolling Stock up to "Semi" Current ORTS Physics for SLI+Other Rolling Stock to TS( Up to a certain point/Route ), but just as you pointed out,..different versions cause things to function differently. 3 different Files had PS-2 Covered Hoppers( all are same body & size, just different packs/Routes ) & all 3 had different Physics. So Yes please, I'll( am sure others could use; always been such a great help ) need the files whenever they can be rendered up( & I mean for all ). Thanks.

[johnnyboy99]

I think we should get a checklist together for all the rolling stock types that have physics files for ORTS
I know certain cars probably don't have them yet, such as those 5 unit container spine cars used by TTX and CP Rail, flexi-vans, 40ft meat reefers, depressed center flatcars, dry ice reefers, etc.