Update on the steamers

[dtrainBNSF1]

Have you seen this from Great Northerner? It might help you with future scenarios.

viewtopic.php?f=20&t=13736

I've got it already. It's really interesting.

I'm already planning for the next mod's scenarios (if it turns out people like the scenarios)

[dtrainBNSF1]

Okay guys, 2 things that I would appreciate your help on.

1) The Challenger mod seems to have become unresponsive on my end. Not sure why. It started a couple of months ago and no matter how I've changed the sim file nothing works. I've redownloaded and reapplied my own mod from the library and again nothing works. The loco moves and there's power, but the steam usage rate soars above 45mph for some reason. I've reduced the effectivity line, I've adjusted and re-adjusted the max output lines, I've reconfigured the exhaust limit, I've reduced the steam usage scalers for CutoffSteamUsageScalar,SpeedSteamUsageScaler, and SteamUsageScaler to .1 each and reduced the BasicSteamUsage to 200 and still when the loco hits 45mph steam usage soars even at 10% cutoff, blower open and dampers open, at ideal fuel mass and the brake handle in running position. I've removed the loco from my library and then verified the game cache to start from the ground up and still it does the same thing. This is the only loco that behaves like this.
What I need from you is to let me know if the Challenger is acting the same way on your guys' end (modified or unmodified). If anybody has any suggestions as to how to solve this issue I'm all ears because I'm stumped after working on this for several months; I can't think of anything else to do with it.

2) The Berkshire has a problem with the brakes; sometimes the brakes release completely to 90psi and sometimes the only release to 88psi, maybe lower. This is causing all sorts of problems on my own personal test runs because that extra 2-or-so psi does make a difference with a heavy train on a steep grade. I have no idea where to begin with brake data. Is anyone else experiencing this, and if so is there anyone out there who knows how to work with brakes who can work on the Berkshire's brake system?

Any help/advice would be appreciated.

[TheOldDessauer]

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[dtrainBNSF1]

This has happened to me as well; I noticed it at first because the smoke emitter fixes stopped working during some of Elphaba's Workshop scenarios for the F.E.F. where the Challenger and Big Boy are used as "supporting actors". I had to uninstall and reinstall the mod to get the emitters working again. However, as the engines were "scenery objects" in the scenario I wasn't alerted to the performance issue. I will boot up and run the Challenger over Sherman Hill to see If I have the same issue with performance. This is weird. ...

P.S. I also have the same issue where I use RW Tools to fiddle with emitters in the Pennsy K4, and the "sinking engineer fix" on the GS-4s. After fixing them with RW Tools, they will be fine. However, if I shut of the game and computer and then come back the next day and play, the emitters and the engineers are reset to "factory specs". All of the Bak files are there, they are just not responding. Very weird.

Agreed. Very weird. On my end it started one night while modding the Challenger again. I was getting ready for another test run when the scenario wouldn't boot, saying that it failed to load the Challenger's engine units due to "modified stock". Naturally the loco stopped rendering in-game, like I had tried to edit a read-only loco like the SD70M. I ran my backup and from then on the Challenger became unresponsive to anything I did. Like I said, this is the only loco this has happened with.

[TheOldDessauer]

u

[dtrainBNSF1]

Okay: I ran the Challenger with a reefer block and caboose, about 4270 tons Eastbound from Laramie to Cheyenne. Train accelerated slowly but steadily. I had no trouble keeping boiler pressure up at 280 most of the way. Once I got to Dale and the grade dropped from .8% to .4% things got weird. As my speed picked up from 38 to 40+ mph, boiler pressure started to drop rapidly; I was having trouble keeping it at 240-250 and only using about 38-40% reverser. Also, the locomotive ran out of water? Tender had 13,000+ gallons left in it and F4 menu said that I had .82 water level in boiler so, what gives?

P.S. Come to think of it, shouldn't I have had a lot more water than that in the tender after having only gone half way across Sherman Hill, or is that normal water usage for your mod?

That sounds like what's going on over here on my end; approaching 40mph I can't maintain steam pressure.

As far as water usage, it sounds like what I was doing before everything went bad.

[dtrainBNSF1]

I had an epiphany when I woke up this morning! There may be a problem with the simulation folder, but that problem may not exist in other simulation files. It's something I've discovered experimenting with some diesel locomotives after watching FanRailer's video all about diesel simulation modification. Some diesels don't render in-game if you edit their simulation file. I figured out that if you take the simulation file from another more co-operative diesel, create a new folder (which I call Simulation2), place the co-operative diesel's simulation file into this new folder, modify as usual, then go to the diesel's engine file and re-route the path of the simulation blueprint so that instead of "..\..\Simulation\.." it reads "..\..\Simulation2\.." that the diesel then works with correct physics.

Simply put, it's a heart transplant for a simulated locomotive.

SO if this works for "bad" diesels, perhaps it will work for the Challenger. I'll take the simulation file from a loco with a simulation file that I know works, place it in the Challenger's directory in a new folder called Simulation 2, edit like normal, reroute the engine files so that it reads the new simulation folder, and theoretically it should work.

I'm busy this weekend, so I might not be able to get to doing this until sometime next week (which btw is the last week of my summer course ).

If anybody else thinks of anything else I could try, please comment.

[TheOldDessauer]

u

[dtrainBNSF1]

A strange thing about the Challenger water usage: When I need to fill up the boiler, I use the HUD. The boiler fills, I turn of the water on HUD and ....water keeps coming out of the tender. I've tried the manual shut-off for the Live steam injector (I) and the Exhuast injector (O), but nether one works. The water just keeps running out of the tender and I can't shut it off.

I've noticed that on the Big Boy as well. Not really sure what to make of that...

Anyhow after a day of investigating, testing and more number crunching I am happy to report that the Challenger is now behaving more or less as it should behave. It turned out to be less complicated then I thought. There's an extra sim file on the simulation folder called Challenger Simulation Extra that I've ignored up until now and when I looked into both that particular sim file and the engine files I noticed that the rear unit (the one the player sits in) references the Extra file. I re-routed the path of the blueprint so that it ignores the Extra file and references the "regular" sim file. Still needs a bit of fine-tuning but it's much better now. Due to the change in the simulation file, the cylinder cocks not only open but the valve is now animated like it should be.

I got tired of the Big Boy not having any sounds besides the default Black 5/S&DJRR 7F chuff, so I copied all of the Challenger sound files over to the Big Boy, did some reconfiguring in the proxyxml files and in the engine files and now the Big Boy sounds like a completely different engine. I changed the whistle to the Big Boy whistle found here: http://www.railworksamerica.com/index.p ... =25:sounds

Needless to say it's now really fun to drive the Big Boy Both engines are going through test runs over Sherman Hill with tonnage to get some things fine-tuned.

These mods will be released later, but they won't be the next mods I release. The next mod will either be the K4s or the Cab Forward, whichever I finish first. The Cab Forward is a little closer to being done than the K4s.

Question for the admins: If I want to update something I've already submitted to the library instead of uploading an entirely new item, how do I go about it? I've repositioned the driver figure in the GS-4 so that he's not dangling through the floor and I would rather just update the GS-4 mod that's already in the library rather than submit a whole new item into the library.

[Chacal]

Question for the admins: If I want to update something I've already submitted to the library instead of uploading an entirely new item, how do I go about it? I've repositioned the driver figure in the GS-4 so that he's not dangling through the floor and I would rather just update the GS-4 mod that's already in the library rather than submit a whole new item into the library.

If you make the new zip file available to me I can swap it out in the library quickly, unless Bob prefers a different process.

[dimovski]

Hello!

On the danger of embarassing myself, without reading this thread, I'd like to ask you a question:

As I am doing the very same thing as you (I started exactly a year ago, in August '14), I hope that we can profit from our mutual knowledge. I'm currently in the process of modifying the War Department 2-8-0, and I'm pretty much stuck at the cutoff-to-TE, and speed-to-TE charts. My problem is, that I do not know if RailWorks uses indicated tractive effort/power figures, which it then adjusts, taking into account resistance losses in the present conditions the engine faces, or if it uses readied drawbar figures?

As the difference is rather miniscule for the only engine I've modified before (UP 9000, and boy is it a joy to drive!), the question never arose until now.

Thanks in advance!


Regards,
dimovski

[dtrainBNSF1]

Hello!

On the danger of embarassing myself, without reading this thread, I'd like to ask you a question:

As I am doing the very same thing as you (I started exactly a year ago, in August '14), I hope that we can profit from our mutual knowledge. I'm currently in the process of modifying the War Department 2-8-0, and I'm pretty much stuck at the cutoff-to-TE, and speed-to-TE charts. My problem is, that I do not know if RailWorks uses indicated tractive effort/power figures, which it then adjusts, taking into account resistance losses in the present conditions the engine faces, or if it uses readied drawbar figures?

As the difference is rather miniscule for the only engine I've modified before (UP 9000, and boy is it a joy to drive!), the question never arose until now.

Thanks in advance!


Regards,
dimovski

I'll answer as best as I can.

From my experience, the sim reads the figures directly from the te vs speed and te vs cutoff files. The loco performs the way you program it to act. The sim calculates the tractive effort in this process:
1)It starts with the base tractive effort at 0mph
2)As speed increases, the sim reduces tractive effort based on the percentages you put into the t.e. vs speed file
3)It then takes that figure and adjusts it based on the percentages used in the t.e. vs cutoff file.

For example with a Big Boy that I've been adjusting for quite some time now: It's base t.e. is 135.375 in the simulation file. I've programmed the Big Boy to maintain full tractive effort up to 15mph, at which it drops from 1 to .999. Then it steadily drops until 35mph where t.e. drops to .995. At 40mph It drops to .985. From there I construct an exponential function to give me a curve from that point to the loco's top speed (80mph), which I've programmed to be .725 (that's what Mrennie used for his FEF 3 at the top speed of 140mph). So at 80mph just based on the t.e. vs speed file the Big Boy produces 98146.875lbf (or 98.146875k-lbf).

From there, the speed testing begins. In the first speed tests, I leave cylinder effectivity at 1 to determine at what cutoff the loco can hit and maintain 80mph. Once I figure that out, I take the value that's there and place it in the 10% cutoff spot. For the Big Boy I determined that to hit and maintain 80mph I needed my cutoff to produce 49% tractive effort at 10% cutoff. So for the Big Boy traveling at 80mph the loco will use 49% of the 98146.875lbf, or 48091.96875lbf. I then repeat the speed tests, all the while increasing cylinder effectivity until the loco's ability to produce steam is exceeded at 80mph at 10% cutoff, and just barely exceeded at that matter.

Mrennie if you're reading this and if you feel like you need to add anything to this conversation or if I've misspoken feel free to interject.

[dimovski]

I've found an answer to my question litteraly 20 minutes before I was typing this, and before I saw your comment!

There's always something like a "wagon file" coming with steam locomotives, and there you're supposed to input a rolling friction coefficient together with a drag coefficient.

In my book, that reads as if RailWorks is doing the Indicated-to-Drawbar transgression itself.

(Ofcourse, just how well that works is another question... Now I have the honour of creating partial Indicated T.E. to accomodate for roller bearings, rotary cams and lightweight rods! Woo...hoo... [Or I could just bring both coefficients down to zero, but that should kill the way RailWorks makes wheelslip work...]


Anyway, my procedure differs a bit... As I don't really use anecdotal evidence. To be honest, the idea that a Big Boy can have a full 1 in the speed-vs-te chart at 15mph is to me. Ofcourse I do not wish to criticise you, we obviously have a different approach towards such stuff.

I usually do something in the lines of this...

...and adjust accordingly.


But I do have some more questions...

If I say that the ideal fire mass is 913lb, would I get 2/3rds steam raised at 608lb? What does the grate limit do? I've seen figures well above 3000, where 150lb/sqft of grate area are pretty much the norm, after that one is essentially blowing his fire out of the chimney. Is the blast exponent the same thing as a blast discharge coefficient? Or maybe the discharge coefficient? Does volume mean the volume of the boiler in cubic feet? How to determine the superheater and drafting effect values? Does length refer to boiler length? Would that, in case of, e.g., the K4, be from the end of the Belpaire firebox all the way to the beginning of the smokebox "collar"? Num Strokes should be set at 2, regardless of the number of cylinders, right? 3 out of 4 values for the blower are rather confusing aswell...


God, that's a lot of questions! Seems like I've forgotten a fair bit since last year...

[dtrainBNSF1]

If you think what I've done with the Big Boy is crazy, wait until you see what I've done to the Berks over the last couple of months And that's after e-mailing the FWRHS about 765.

The fact that 8Fs had only 53-54% tractive effort available at 25mph is for me, so we're equal there.

Just remember: the locos I've modded are products of the superpower era, its main theme being "power at speed". These engines could move long, heavy trains at a good clip (Big Boys were meant to move 3000-ton trains at a sustained speed of 60mph once beyond the mountains; Union Pacific had to adjust its tonnage rating of the locomotive so many times that by the end of their careers they were pulling nearly 8000-ton trains over the Wasatch Range). Maximum tractive effort was reached at 10mph, maximum horsepower at 35mph. I work with the sources I've got, mostly from steamlocomotive.com or wikipedia (I don't prefer using wikipedia, but whatever useful information is there I gladly glean). Plus the Big Boy mod I'm revising is still technically WIP - I'm still making adjustments.

Anywho, so with what you asked:
1) I don't mess with the rolling friction coefficient or the drag coefficient as I don't know how to compute those values, or if the way you'd calculate those in real life applies to how they figure them in Railworks. I work with what I know.

2)Modding steam locos in Railworks is largely a "black art"; while we can figure amounts like steaming rate and the superheater's ability to produce steam, several other figures come from lots of trial-and-error.

3) As far as ideal firemass, all I can say is that most of the time I don't need my firemass up there unless I'm hauling heavy tonnage over a long grade. With light passenger trains, light or heavy grade, having a smaller firemass should be adequate to maintain track speed and build steam (If you've got more fire than what you need, you'll build too much steam and blow it out of the safety valves, wasting the coal/oil and water needed to make it). That being said, I don't know if it's an exact 1:1 ratio of firemass/steaming rate. You'll have to figure that out over test runs.

4) Grate limit, according to the developer docs, is the amount of coal/oil burnt in an hour (lbs/hr).

5 )I don't know what the blast discharge coefficient is. I can tell you what the blast exponent is and you can figure it out from there: blast exponent, according to the developer docs again:

"Exhaust steam is released from the cylinders, via the blast-pipe located inside the smokebox.
Aimed up the chimney, the jet of steam blasting up through the smoke-box draws air
through the fire and along the boiler tubes and out the chimney. This parameter simulates
the efficiency of the Blast Pipe and impacts the Firebox Temperature"

6) Yes, volume is measured in cubic feet. HOWEVER this figure does not always follow the prototypical measurement of the real-life boiler, as Mrennie discovered while working on the FEF-3. You may have to increase this value to a larger-than-life figure.

7) For the superheater, use this formula: 1+(superheater area/Heating surface [tubes and flues])
Drafting effect: this is determined by trial-and-error until it "feels" right.

8) Length refers to boiler length and affects how the water behaves in the boiler on grades. Again may or may not follow to real-life figures. Adjust until it seems right to you.

9) Yep, number of strokes should always be 2; it's not like modern electric engines with fancy 4-stroke technology.

10) I'm confused by the blower values as well. I see trends as I inspect the files, and so I leave those be.

I'm still learning this as I go along; that's why I've got 2-3 versions of the same mod either released or in development I'm by no means an expert.

[dimovski]

Well, good we met, then!

I did do some homework about the 2 friction coefficients in the "wagon" file, and found out that:

Rolling friction coefficient is essentially what it is. If you move it to .999 the loco will sort of move at 0.5mph (okay, with a 1000 ton train in the front, but after 5 minutes and no acceleration... um, you get the point), but the wheelslip mechanics haven't been compromised.


Now, as the Davis equation is in the form of R=A+B*V+C*V^2, I think C can be ruled out as a drag coefficient. A is a constant but becomes insignificant rather soon, it seems, and B is a coefficient. This means that B and C can & should be easy to simulate in RailWorks without significant hassle, maybe only a slight adjustment for A is needed.

This gets more interesting by every day.




Something interesting I found out about wheelslip is that it works rather well on even track, if you use 1.0 for dry rails adheasion. Yes, with a heavy train you have to sand until you're really moving (10-15mph), but then it should be fine. The only thing left to check is grades... I have that terrible feeling that won't work out as well...



About the 8F having low TE at 25mph... Pulling 1000 tons on level track at 41mph is well in the capability of her. Which is quite impressive, considering the meager power output of 1462/1553/1650hp (OpenRails/Adjusted OpenRails/From a Turkish datasheet...), at a critical speed (after which maximum power drops) of 36.7mph. Not to mention the terrible terrible grate area of 30 square feet and a barely-noticable superheater of 0.18*1690 square feet... And did I mention that British firemen were "only" allowed to shovel 3000lb per hour?



PS:If you want help with your K4, this might be useful:
http://prrthsdiscussionweb30239.yuku.co ... cZSu_ntlBc
I believe evaporation rates and horsepower are discussed here.
http://5at.co.uk/index.php/references-a ... tware.html
If you download "Perform", it has a few inputs for american steamers (most notably an ATSF 4-8-4 and the PRR K4).
Once you've downloaded it, pick the K4, put cover temp to 180, change the discharge coefficient to 0,99 (",", not ".") [0.99 for standard exhausts, 0.9 for Kylchap, double-chimney or LeMaitre systems], now pick a constant speed, vary the cutoffs => cutoff-vs-TE chart. Constant cutoff, varying speed => speed-vs-TE chart.