Suggestion by a newcomer – NumWheels-Adheasion-slippery

At the risk of being shot down in flames, I'd like to offer a few suggestions as regards some settings vis-a-vis steam power in the sim.Let me start by saying that I have spent quite a number of years researching the technical side of railroading, especially US "modern" steam.In my railroad library, I have four particular books, which I consider to be the the four gospels of steam railroading:1)The Steam Locomotive
by Ralph P. Johnson, Chief Engineer
Baldwin Locomotive Works (1942)2)A Practical Evaluation of Railroad Motive Power
by Paul W. Kiefer, Chief Engineer, Motive Power and Rolling Stock
New York Central System (1948)3)The Steam Locomotive in America
by Alfred W. Bruce, Asst. V.P.Engineering, Steam Locomotive Design
American Locomotive Company (1952)4)The Red Devil and Other Tales from the Steam Age
David Wardale (1998)As soon as I got MSTS, I set about to determine how realistically various units perform. It became clear to me that diesel and electric power can be very easily tweaked to perform quite predictably and prototypically, especially if you apply the well thought out and executed physics revisions of Bob Boudoin and Joseph Realmuto, and others.Steam, on the other hand proved a huge disappointment. I downloaded (while salivating in anticipation) the UP Steam Pack, and then watched in disappointment as 844 slipped furiously with a "soft touch" on the controls, and a light consist well within her design capabilities.I searched the web in vain for a fix that was both effective and within the bounds of reality. I tried some fixes and rejected others as purely ridiculous ( "set the following adhesion parameters 2 2 2 0" ). None gave the desired results.Suddenly I had a thought. What if instead of wheels, axles etc., for NumWheels, I plugged in the raw percentages for weight on unpowered wheels, and drivers. Example:*****Wagon ( FEF-3_UP_1
comment( 4-8-4 FEF-3 Steamer )
Type ( Engine )
WagonShape ( FEF-3_UP_1.s ) Jump down Mass ( 222.58t )
#( Total Engine is 376.75t, 830,600 lbs with the Tender 2/3 loaded )
#( Total Engine is 222.58t, 490,700 lbs without the Tender )
#( Total weight on Drivers is 122.61t, 270,300lbs )

Jump down #( this is for the Wagon section, the first NumWheels parameter, % total weight on engine and trailing trucks 222400/490700= 0.449 ) Numwheels (0.449) #( this is for the Engine section, the second NumWheels parameter, % total weight on drivers 270300/490700= 0.551 ) Numwheels (0.551)*****I restarted the simulator and no more "slippery sister". She walked right off with the short train I had on her drawbar.OK, the acid test. I had previously loaded Test Track route from the file library here. The route has a 15 mile, gradeless speed loop and three grades for testing MSTS trains. The grades are 1.8%, 2.83% and 6.1% (the original figures in the download appear to have some "rough" math. Mine were verified taking measurements in Route Editor.)Next, I worked up an adjusted tonnage rating for the old girl and sent her up the 1.8%. Up she went, at a very prototypical 8 MPH.Will she slip now? Yes, when conditions warrant. Too much power in tunnels, in rain or snow and she'll lose it. but properly run she'll pull like God and ALCO intended.Let me know what you think. I've made other discoveries, but this is enough for now.I'm still trying to work out the high end performance, oil (coal) and water use etc. She runs too fast "as is / out of the box" with any given load. Up to about 10-12 MPH, the cylinders are the limiting factor, so the drag test above is valid. It's the balance between boiler and cylinders that needs to be put right, to develop the proper HP at speed (4700 IHP according to UP tests with a dynamometer car). Regards.............

Regards,
Nick

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RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, KeltikSylk, Sep-27-04, 01:35 PM, (1) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, plainsman, Sep-27-04, 01:58 PM, (2) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, KeltikSylk, Sep-27-04, 04:47 PM, (6) RE: Suggestion by a newcomer--NumWheels-Adheasion-slip, chucksc, Sep-27-04, 11:36 PM, (8) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, KeltikSylk, Sep-29-04, 08:44 AM, (19) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, plainsman, Sep-29-04, 12:21 PM, (20) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Yankee15, Sep-27-04, 02:28 PM, (3) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, johnf, Sep-27-04, 03:23 PM, (4) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Yankee15, Sep-27-04, 04:09 PM, (5) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, black5, Sep-27-04, 08:24 PM, (7) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Yankee15, Sep-28-04, 04:01 AM, (9) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Roman, Sep-28-04, 09:25 AM, (10) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, scottb613, Sep-28-04, 11:02 AM, (11) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, baldwin, Sep-28-04, 05:21 PM, (16) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, GaryG, Sep-28-04, 12:47 PM, (12) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, plainsman, Sep-28-04, 01:26 PM, (13) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, henry3, Sep-28-04, 02:32 PM, (14) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, GaryG, Sep-28-04, 02:41 PM, (15) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Yankee15, Sep-28-04, 06:12 PM, (17) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, crick14a, Sep-29-04, 03:49 AM, (18) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Bill Hobbs, Sep-29-04, 05:05 PM, (21) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, crick14a, Sep-30-04, 02:29 AM, (23) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, supergoods, Sep-30-04, 06:43 AM, (24) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Roman, Oct-01-04, 10:27 AM, (27) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, crick14a, Oct-03-04, 05:32 AM, (28) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Bill Hobbs, Oct-03-04, 09:27 AM, (29) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, chucksc, Oct-03-04, 10:39 AM, (30) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Bill Hobbs, Oct-04-04, 11:55 PM, (35) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, crick14a, Oct-03-04, 05:09 PM, (31) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Bill Hobbs, Oct-03-04, 08:42 PM, (32) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, crick14a, Oct-04-04, 03:23 AM, (33) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, plainsman, Oct-04-04, 03:45 AM, (34) RE: Suggestion by a newcomer--NumWheels-Adheasion-slipp, Bill Hobbs, Oct-05-04, 00:02 AM, (36) Some ideas from past forum discussions, Bill Hobbs, Sep-29-04, 10:55 PM, (22) RE: Some ideas from past forum discussions, scottb613, Sep-30-04, 08:33 AM, (25) RE: Some ideas from past forum discussions, crick14a, Sep-30-04, 11:05 AM, (26) RE: Some ideas from past forum discussions, supergoods, Oct-06-04, 10:08 AM, (37) RE: Some ideas from past forum discussions, crick14a, Oct-06-04, 12:59 PM, (38) RE: Some ideas from past forum discussions, supergoods, Oct-08-04, 12:36 PM, (42) RE: Some ideas from past forum discussions, crick14a, Oct-09-04, 01:00 AM, (43) RE: Some ideas from past forum discussions, Roman, Oct-06-04, 05:12 PM, (39) RE: Some ideas from past forum discussions, kenya, Oct-06-04, 06:00 PM, (40) RE: Some ideas from past forum discussions, Roman, Oct-06-04, 06:21 PM, (41)

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I know I've read repeatedly that the "quantities" in the ENG files were not straight forward values, but some sort of factor that Cujo used. So your idea sounds feasible enough to me...Let me make sure I'm following what you are saying. For Engine parameters you take the total locomotive weight/weight on drivers = percent weight on drivers. In your case .551 or a little over 55%
If I subtract this from 100% it gives me the Wagon parameter, nearly 45%The actual number of axles (or wheels) has no bearing on the factors.Would this work on electrics and diesels? Frank MusickMoving America into the 19th Century!

www.kelticsylk.com

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LAST EDITED ON Sep-27-04 AT 02:13 PM (EDT)

"Would this work on electrics and diesels?"
NO!!! (emphasis added out of panic not anger) We already have the diesel and electric model working as it should.
"As soon as I got MSTS, I set about to determine how realistically various units perform. It became clear to me that diesel and electric power can be very easily tweaked to perform quite predictably and prototypically, especially if you apply the well thought out and executed physics revisions of Bob Boudoin and Joseph Realmuto, and others."
Let me explain the panic. There are numerous ways the adhesion and numwheels lines can be set up to work reasonably well together in the diesel and electric model. The only caviate is that the way V4.5 and V4.7 handles numwheels gives the best sanding values. If we go to something else, we loose the optimum sanding adhesion. Now another problem, is I have done a LOT of work to get the files set up properly for the present adhesion/numwheels integration. If we change that, then I have to go back and redo spreadsheets and other calculations, a LOT more work for no benefit.
Bob

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Bob,
Didn't mean to hit any buttons. I was only interested in how this might effect the big articulated electics and diesels I've been building.I'm really not familiar with the work you and Joe have done, though I am going to make a point to check it out. Chuck Zeilor has been doing all that work. I'm just beginning to understand some portions of the ENG file parameters and don't know enough to contest anything anyone's done.Frank MusickMoving America into the 19th Century!

www.kelticsylk.com

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Frank Electrics work sorta just like the diesels, but with the addition of a short time overload capacity the diesels don't have (e.g. the AEM7 is really 4.5k hp or so but can deliver 7khp for a "short time" while a Diesel is strictly limited to what the prime mover can produce)!
Bob, Joe Realmutto and I spent ages debugging that...
Look at the AEM7/ALP44 physics for that (and yes we owe you an update to those also... Along with the GG1s and EP5s)
The primary problem with articulated 2 or 3 part engines (Steam, Electric or Diesel) is that other than the primary "driven" unit MSTS uses a very simplified (did I mention simplified) physics model that only parses about 1/3 of the code the "driven" unit does...
That means you have to look at them "in toto" in order to get proper performance.... The problems with the UP package were due to us going down a "wrong path" on how to do that in reaction the suggestions of a few of our users that seemed extremely practical until we actually did/tested them and the problems did not become apparant until after we released them and people used them in other than our test configuration (In other words I/We screwed up)... We will release updates to fix that... BTW, HAC Clitheroe has been ill and so that sort of thing is stuck in his hopper.... Also Phil Moberg has been ill also and that is why the EP4/EF3 is stuck along with the Washboard EMUs.....Chuck Schneider
Chief Cook, Bottle Washer and (Virtual) CEO

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Bob,
Went looking for your stuff and found a lot of it, but it still begs a couple of questions for me...All the physics seem to be for A-1-A, B, and C running gear on diesels. In the case of "heavy" electrics and diesels, with 4 powered axles or more, do I just change the number of wheels?And does "wheel" in an engine file mean the same thing as axles?Frank MusickMoving America into the 19th Century!

www.kelticsylk.com

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LAST EDITED ON Sep-29-04 AT 12:23 PM (EDT)

Hi Frank,
For the diesel and electric model, NumWheels has NOTHING to do with the number of wheels, no matter if there are 17 wheels, it does not matter. It is simply a factor (a divisor) which integrates with the adhesion line and the sanding value to give proper adhesion.
Lets look a little closer:
Adheasion ( 0.29 0.53 2.0 0 )
Is the adhesion line from a GP38-2 (would be the same for any GP(x)-2 or SD(x)-2).
NumWheels ( 4 )
This is the second NumWheels. You will note that the second NumWheels is 4 on all locomotives 3 wheels or 27 wheels, it does not matter. The third value in the adhesion line is 2.0 unless one or more axles is unpowered. Then that is reduced to account for the difference. The ratio of third value to NumWheels must be 2/4 to get sanding adhesion correct. I don't have time now to go any further, but would be happy to explain more later.
Bob Boudoin

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You are reading that correctly. I'd not mess with Bob's work on diesels and electrics. I would not presume to question his work.I have tested his engines on the test track grades and speed loops and they are dead-on-balls-accurate (technical term from the movie "My Cousin Vinnie".)The only change I had to make, (and he specifically addresses it in the readme doc) is to coupler strength. MSTS cannot handle the standard Type E coupler strength of 500.000 lbs. The engine kept parting from the train.My suggestion appears to work, but I'm not proposing it be made a standard. Try it and see how you like it. Make a backup of the original loco, in case you determine that I'm "all wet" ( ie: not superheated).

Regards,
Nick

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This is a very interesting and novel approach, as the goal is to achieve accurate performance rather than accurate figures in the eng file, something I always advocated. So I have a few questions.Did you alter any other figures in the eng file?
Have you tried this on anouther Steamer? I know that 800 class is well documented and makes an obvious choice.keep at it, fresh ideas are always welcome

john fowlis
CPHS

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LAST EDITED ON Sep-27-04 AT 04:50 PM (EDT)

I have applied the same approach, to the Challenger and Big Boy engines with equally good results. Ditto with TA's ESE J3a Streamlined Hudson, and 3DTS's AT&SF 3751. I have been monkeying around to one degree or another with all of the engines, attempting to apply real world numbers and make them work. I have William Kratville's books on all three engines and they have technical data of all kinds.Evaporation and fuel data is plugged into all three engines, directly from test results printed in the books, even to the degree that I have changed the "coal" parameters on the oil burners to correct for Bunker C fuel oil instead of Hanna and Rock Springs, WY coal. Hanna and Rock Springs were where the two company owned mines for UP stoker coal were located.Bunker C (#6 Heavy Fuel Oil) weighs 8.1 lbs/gal and has a calorific value of 17,500 Btu/lb vs. UP standard steam coal which yielded 11,300 Btu/lb.I am working on getting the engines to consume the proper quantities of coal (or oil) and water, for the work performed. This is tricky, as the game was evidently designed for the small non-US engines supplied with it. Steam at 140 psi has vastly different properties than at 300, or 280 psi.One real stand-out screw-up--it appears that the game registers a gallon of water as 10lbs instead of the actual 8.34lbs, so you have to set up the parameters for the water in the tender as 250,000lbs to have the sim display 25,000 gals. If you enter the correct weight of 208,500lbs the sim shows 20850 gals in the tender. Of course that screws up the water rate of the engine and makes it that much more difficult to get the engine to "drink" properly.As you can see, I am hardcore. I can't even enjoy the game until I make it do what I want it to.But there is fun in crunching the numbers too.It's like pitting myself against the sim at the primal level.If and when I solve these issues, I will publish the results on this forum.

Regards,
Nick

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Interesting topic...I too like to get as 'real' as possible and look forward to trying out your 'discoveries'..all input is welcome..!!!
Don't forget that the gallons are UK ones which are 1.22 bigger than US gallons...!!
Can't quite understand why the volume of water affects- "the water rate of the engine and makes it that much more difficult to get the engine to "drink" properly."- ..????
There are lots of good info from similarly minded people on UKtrainsim.com (Physics section of the Forum) on steam usage.coal burnage.evaporation.etc etc...!!
Thanks again for the info..keep it up..Georges

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LAST EDITED ON Sep-28-04 AT 04:06 AM (EDT)

>Interesting topic...I too like to get as 'real' as possible
>and look forward to trying out your 'discoveries'..all input
>is welcome..!!!
>Don't forget that the gallons are UK ones which are 1.22
>bigger than US gallons...!!
>Can't quite understand why the volume of water affects- "the
>water rate of the engine and makes it that much more
>difficult to get the engine to "drink" properly."- ..????
>There are lots of good info from similarly minded people on
>UKtrainsim.com (Physics section of the Forum) on steam
>usage.coal burnage.evaporation.etc etc...!!
>Thanks again for the info..keep it up..
>
>
>
>Georges Thank you so very much for making me aware of the gallon issue.What I meant was, for every 8.34 pounds of steam used I had expected to see a gallon of water disappear from my tender. But if they are using Imperial gallons, I can not plug real life steam lbs/hr values in the locomotive and have the gallon figure in the tender reflect US gal/hr usage.If Big Boy is climbing a sustained grade of 2.2% (1 in 45), such as on Cajon Pass, at a speed of 15 MPH, at 70% cutoff she's using 22 lbs of steam for every revolution of her drive wheels. Withe the engine operating at 74.15 RPM that's a water rate of 97875 lbs/hr, excluding aux. steam usage. That's 11736 US gallons, but only 9619 Imperial gallons. Big difference there. If I want to see the gallons per mile figure in the tender reflect the real thing, I'll have to make the engine consume 20% more steam. That means bumping the CylinderVolume up by 20% for example.

Regards,
Nick

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I think Kuju uses the metric system as a default. And metric systems are by nature strictly decimal ( 10, 100, 1000 etc ) So, I assume it is best to convert your prototype american or imperial values to the according metric units ( liter/ cubic meters or kg / tons ) and provide those metric params to the eng/wag file. This will avoid unnecessary side effects.( as the gallon/lbs mentioned above )Roman

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Hi Nick...Great stuff - and - it is sorely needed... I was always hoping someone would do the work on steam engine physics - the way Bob did it for Diesels...Have you looked at Anrdre Mings - North Arkansas 4-6-0's... I like the physics on these locomotives... They seem well done - however - I am no expert...I would like to attempt to improve my steam locomotives as well... Would you - maybe - be able to list the mods you made for various loco's... I would love to give them a go... Maybe you could be the "Plainsman" of steam... Lastly - have you looked at the new Cab Forwards... The wheels never slip - no matter how hard you "gun" it... I think they probably should slip in some situations...I like'm as prototypical as possible...Thanks,
Scott

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You could try using this line CylinderEffectivity instead of increasing the cylinder volume. It may however have a knock-on effect elsewhere. One thing to remember with the steam eng file is that no parameter relating to fuel/water can be taken alone, there are usually two or three more linked to it, some not very obvious.Beer is not a matter of life and death. It is much more serious than that.
mervyn.

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LAST EDITED ON Sep-28-04 AT 12:48 PM (EDT)

HiGreat observation and well thought out as a steam solution.I notice it's already been shot down as a solution for diesel and electrics. My thought is it actually might be a solution for any loco that has unpowered axles, steam, diesel or electric.There were a few loco models built with unpowered axles, both electric and diesel. One diesel that comes to mind is EMD's GMD1 which was built for light rail and had six wheel trucks but the center axle was unpowered; there was also one of the earlier EMD passenger locos that I think had an unpowered center axle also. There were also many electric locos with unpowered axles, the GG1 comes to mind.Perhaps with this percentage of weight method and a few other adjustments we might just end up with locos that mimic the real thing a bit closer. Isn't this what we're after, behaving like the prototype under as many conditions as possible?GaryG

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Hi Gary,
I beg you not to get this going this way!!! The answer for diesels and electrics with unpowered axles can much more easily be addressed in the third value of the adhesion line. If you start messing with numwheels, you will mess up the sanding adhesion. It will also require a complete overhaul of all the adhesion values. This would create a lot more work for something that can be handled easily in the other manner, and without wrecking the sanding adhesion. It seems to me that KUJU had different resources writing the diesel and electric physics work from those that did the steam work. I don't think some of the data is used in the same way. So what would work for steam wouldn't create reality in diesels. We already have the tools to get even A1A EMD E units performing very realistically in the simulator. Let's not muck the diesel and electric model up with unnecessary methods.
Bob

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Agreed wholeheartedly!Henry

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Hi BobIn my note I did have some "mights" and "perhapses" (is that a word?). I wasn't saying to use the percentage method, just suggesting it might be an alternate solution in some cases.I realize you and others have done much research into this area and have helped make MSTS more realistic. I know much time has been invested in looking for solutions to the many MSTS shortcomings.With all this said, I'm just suggesting we should at least allow for the fact that perhaps a better solution to any problem could be found. I'm not trying to start a flame war in any way, I'm just saying we should all try to keep an open mind to the possibility that an improved solution might be discovered. If someone wants to spend time researching and proving the results this method might give, we shouldn't immediately discourage that person. We need to encourage experimentation to be able to perhaps continue improving the way our trains and equipment behave.GaryG

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LAST EDITED ON Sep-28-04 AT 08:31 PM (EDT)

I'm sorry for causing you angst, Bob.I didn't realize a small suggestion would cause a revolt.I'll state this again for the record:I WOULD NOT MESS WITH BOB'S STANDARDS.
I DO NOT PRESUME TO QUESTION HIS WORK.I have tested his engines on the test track grades and speed loops and they are dead-on-balls-accurate
Thanks again for all your fine work Bob.

Regards,
Nick

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NickWelcome to the clubBelow some points of interest for you........Missing parameters and they do work all can be found in the loadstr file in ffedit utils folder"BoilerRadius")"CriticalBlowbackLevel")"SteamMaxWaterHeightMultiple")
"SteamPrimingPowerLossProportion")
"SteamPrimingWaterUsageIncreaseProportion")
"SteamPrimingInjectorsFailAtLevel")
"SteamPrimingReductionWithCylinderCocksOpen")"SteamFiremanConditionLossRateConstant")
"SteamFiremanConditionGainRateConstant")
"SteamFiremanEnergyLossRateConstant")
"SteamFiremanEnergyGainRateConstant")
"SteamFiremanMaxConstantFiringRate")
"SteamFiremanMaxPossibleFiringRate")
"SteamFiremanEnergyUsedPerPoundOfCoal")
"SteamFiremanIsMechanicalStoker")"SteamOilBurnerMinBurnRate")
"SteamOilBurnerMaxBurnRate")
"SteamOilBurnerControlExponent")
"SteamOilBurnerSteamFromOnePoundOfOilBurnt")"SteamOilBurnerMaxRateOfTempChange")
"SteamOilBurnerEfficiencyExponent")
"SteamOilBurnerMinBurnerTemperature")
"SteamOilBurnerMaxBurnerTemperature")"SteamOilBurnerTemperatureChnageExponent")
"SteamOilBurnerSteamGenerationExponent")
"SteamOilBurnerSmokeForOnePoundOfOil")
"SteamOilBurnerSteamFuelType")"Firebox")If you can give out of the books you have, anything relating to the oil burning sections it would be much appreciatedRegards, Rick

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I tried to make the oil-burner parameters work well over a year ago--without success. The locomotive steamed, but seemed to be following some default assumptions about the fire behavior. If you can supply an example of a set of variables that will work, I believe I have enough info available to create a decent representation of an oil-burner.

Bill Hobbs

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BillWe probably came up with the same results then, but if you have anything as good as the other info you have put forward please do
anything relating to these questions below the Exponent does not
matter to much.I think technically there should be nowt in the box to begin with
or very little anyway here in the UK we never had that many Oil run
engines around so info on the subject is very limited if any at all.Regards, Rick"SteamOilBurnerMinBurnRate")
"SteamOilBurnerMaxBurnRate")
"SteamOilBurnerControlExponent")
"SteamOilBurnerSteamFromOnePoundOfOilBurnt")"SteamOilBurnerMaxRateOfTempChange")
"SteamOilBurnerEfficiencyExponent")
"SteamOilBurnerMinBurnerTemperature")
"SteamOilBurnerMaxBurnerTemperature")"SteamOilBurnerTemperatureChnageExponent")
"SteamOilBurnerSteamGenerationExponent")
"SteamOilBurnerSmokeForOnePoundOfOil")
"SteamOilBurnerSteamFuelType")

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I have been experimenting with the effect of some of the unused parameters for some time.I agree with Rick that they do all work in some way, however I have a suspision that they are somewhat of a developers notebook and the effect intended may have been modified by later hard coding in the final program.One commonly used pair of parameters where this occurs are the two hand firing parameters:SteamFiremanMaxConstantFiringRate ( 3000 )
SteamFiremanMaxPossibleFiringRate( 6000 )The presumed intent of this is to limit the overall firing rate to 3000 while allowing the actual firing rate to be as high as 6000 for short periods.What actually happened is that the hard coding took the higher value (In this case 6000) and then fired at the short period rate of about 1.8*6000, or 10800 which is way beyond normal human capability.When I removed the MaxPossible parameter, I started to get an actual maximum firing rate of 1.8*3000, or 5400.This is just an example of what may happen and I would advocate using these parameters only with a great deal of caution and testing to make sure they do in fact do what they appear to do

Supergoods

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You can't do an oil burner or a coal dust burner close to prototype.( or at least I#am not able to do this ) Kuju did not realize the differences. Both of them don't have a burning rate during idle time (up to a certain time, I know). They have a much faster 'firing-rate responsivenes', which can be workarounded to a certain degree by boiler responsivness, you can't simulate the usage of steam for firing (this affects stoker firing as well), the fire does not get worse over time. They interact different to the blower. And worse, no adequate sound and missing triggers for doing a good one.
Roman

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Would still be appreciated if anyone had any of the figures/values
requested in a different part of this thread........Rick

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Rick,
If you are referring to the oil-burner info, I do have some info you might find useful. I've not been online for a while do to other obligations. I thought an "empty nest" would create more free time, but just the opposite has happened.

Bill Hobbs

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> I thought an "empty nest"
>would create more free time, but just the opposite has
>happened. Hey Bill you ain't seen nutten yet!
Wait til the grandkids start arriving...
You'll have even less free time....
lol!
Chuck Schneider
Chief Cook, Bottle Washer and (Virtual) CEO

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Chuck,
My goal is to have retired, sold the house, bought an RV, and headed west into the sunset leaving no forwarding address before that happens. I also want one of those bumper stickers for the RV that says "I'm spending my kids inheritance".

Bill Hobbs

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BillIf you have anything relating to the parameters mentioned earlier
in the tread you could put up would be appreciated, as I said afore
oil burning stats are very limited for steam in UK if any at all
not much in any of the books I have on locomotives....Rick

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Nick,
First thing is that the BTU rating for oil can be assumed to be around 17,000 BTUs per lb. If you have seen my spreadsheet for Fuel and Water Factors (misc section of the library), it was created for 13,000 BTU coal. So the burn rates can be reduced by 13/17 to come up with an appropriate rate of fuel consumption.
The first difficulty I found with TrainSim was that I couldn't get any useful results without specifying an IdealFireMass. I didn't have any luck setting it to zero, but it might be worth another try. Oil burners don't have a firemass, just different rates of firing. The MinBurn and MaxBurn variables were intended to set up the minimum flow of oil needed to keep the fire burning and the max feed rate for the loco. You can try setting these so the upper end will be sufficient to generate the lbs of steam you need for your boiler throughput (based off the BoilerOutput variable). The lower end can be set to anything you think might be useful for testing to see if there is any change. It might realistically be as little as 4 - 5 lbs of oil per sq ft of grate area.
Another problem I didn't have any luck with was attempting to fire with the firebox door closed -- the same problem we have simulating a stoker.
In real life, oil burns hotter than coal and the rate of heat exchange is greater (also the rate of damage to the firebox walls). For temp, the max temp that TrainSim allows is 1000C. A range between 500 - 1000 might be good to test with, to see if anything ever changes.
I initially tried setting all the exponent and rate-of-change fields to 1.
I never knew what to do with the "SteamOilBurnerFuelType" variable, so I tried putting it in with no values, just the parens. Who knows, it might be looking for something like "oil", or "1" or "0".
Let me know if you have any more luck than I did. Its been over a year since I tried and I can't recall everything I tried, but I did work for two evenings trying various combinations.

Bill Hobbs

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LAST EDITED ON Oct-04-04 AT 03:34 AM (EDT)

BillYes I grabbed your info ages ago as soon as it was put up.Ideal fire mass well although it's only vapor there has to be something there in the 1st place anything you come up with
on the subject will be interesting.Some thing below for you to consider something that was 1st show
on this forum many many moons ago but not understood why it was solook at these set of start parameters below I shall explain...
comment(fire temp, fire mass, water mass, boiler pressure,
water level, tender_water_mass, tender_coal_mass,
smoke_quantity, fire_condition, coal quality )
EngineVariables( 800 1400 2362 180 0.75 30000 200 13440 1 0.75 )I found as I said before, that the figure 200 on the right of center
represents not the full tender amount of coal/fuel but the amount
that has not yet being fully burnt i.e. 200lbs so I'm saying that
there is a starting mass of 1400lbs but 200lbs has not yet been fully ignited therefore smoke is seen at the start and this will give you the proper combustion effect of a good color emission from the chimney and not clouds of black that in real terms was
wasteful, buy increasing the figure or lowering it will effect the
start emission, the tech docs for this parameter say figure should
be between 0 and 1 the lower the figure less steam produced, in my
opinion this is incorrect and it should be between 0 and what ever
how many lbs of fuel just added to the fire mass for you to start off
with, if left at 0 you will have the 1400lbs of fully burnt through
fuel in the box and no smoke from the chimney/stack at all put the tender coal mass in and the fire in realty goes out, you will find
now in manual and auto firing that the chimney/stack will clear and
darken as it should do in normal running.I reckon Kuju got the smoke_quantity and tender_coal_mass, comment around the wrong way by the way Ian ( Supergoods ) agrees with me on this.Try it Bill, see the difference it makes...........Rick

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Hi Bill,
Did you try a value like 2.5 or 0.8 for IdealFireMass? The program may have trouble with 0, and it is a finite number, maybe even 75?
For SteamOilBurnerFuelType ( 1 ) I would suggest this switch.
Hope this helps,
Bob

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Bob,
This discussion has inspired me to give it another try. Perhaps I'll have some time tomorrow night. It would be nice if an oil burner could be made to work.
This evening I've been working some on a non-virtual model loco that has some binding in its mechanism. My guess is that there is too much play in some of the bolster frames. I've been trying to solder shims on the edges. Used to be easier to do when I could see small stuff better. At the rate things are going, I'll soon be able to only see to work on the full sized ones.

Bill Hobbs

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Nick,
Welcome to the world of trying to make TrainSim steamers more realistic. Your reference library will serve you well as you try to piece things together. Let me review a number of useful things that have been pointed out on this forum in the past that you may not yet be aware of:
(1) Kuju missed the fact that steam locos are reciprocating cylinder engines. Th get proper steam usage, double the actual cylinder size.
(2) Kuju assumes a fixed density for steam, regardless of pressure of level of superheat. Using the CylinderEffectivity variable, which acts as a simple multiplier for the amount of steam flowing through the cylinder, you can modify the density to at least equal that of the density at the loco's maximum boiler pressure. Some time ago I published a table with values for the CylinderEffectivity variable and other variables as well, including CoalBurnage. They are available in the library, I think in the Misc section.
(3) If you have not yet downloaded a copy of F_Calc 2.0, do so. Joesph Realmuto has figured out how to get the proper "check mark" shaped resistance curve that takes the high starting resistance into account.
(4) Basic Coal Burnage. My references say that a loco simmering without exhaust or blower draft will burn 10 - 12 lbs of coal per sq ft of grate area per hour. If you know the approximate or actual grate area for your loco, this value is easy to peg realistically.
(5) IdealFireMass. Hand fired locos tended to keep a fire thickness of 8 - 12 inches while stoker fired locos had 4 - 6 inches. Assuming coal to weigh 40lbs per cubic foot, you can easily determine a number for the type of loco you are setting up. When working the loco lightly, I have found that one can easily let the fire mass drift down to 75% of the ideal mass without compromising steaming ability while reducing pop-off waste.
(6) To more realistically simulate the steam generation effects of working with and without draft, try setting DraftEffectivity to about 1.25 - 1.3 and BlastEffect to about .5. This will closely replicate the boiler efficiency curves that you find in Bruce, Wardale, and Johnson.
(7) Kuju's cylinder performance is too efficient. The curve follows the isothermic expansion curve and does not take account of backpressure, compression, loss of heat through the walls, etc. into account. I haven't found any remedy for this.
(8) Adhesion. Joe Realmuto has provided a very useful analysis of Kuju's treatment of adhesion. You can find his analyses by doing a search on this forum. Basically he shows that Kuju uses the total loco weight, rather than adhesive weight, in its calculation, and that NumWheels functions as a divisor. So it doesn't really matter what value you use for NumWheels as far as adhesion goes. What really matters is how you determine what the maximum tractive force under each of the conditions will be. There has been a long discussion on this forum about what values to use in determining how much of the loco's maximum tractive force can be translated into horizontal motion. While the theoretical coefficient of adhesion for steel on steel is 25%, sanded rail makes a little higher number possible and normal rail conditions are probably not ideal, so the coefficient for normal rail will be less than 25%.
There is plenty more that I cannot think of at this time but this should be sufficient to generate a few comments.

Bill Hobbs

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LAST EDITED ON Sep-30-04 AT 09:18 AM (EDT)

Hi...It seems like we have a few great looking steamers in the pipe... The SF Northern - the SP cab Forwards - and - it also looks like there is an SP Consolidation in the works - over at 3dTrainStuff...OK - while I am a "newb" at playing around with physics - I would very much like realistic physics with my steam engines - therefore - I have been following this thread with great interest...#gulp - i think this is the deep end of the pool - #So - with my 18 page print out of the TA Mountain in hand...I chose this "eng" file first - since it seems to handle pretty realistically - wheels seem to slip when they should - power seems believable - etc... My question: is this a relatively good "eng" file ??? I would like to see an example of one that is done well... If this one is not - are there any steam loco out there - that behaves with - what this group would term "realistic physics" ???Thanks,
Scott

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I have just got hold of the 3DTS Cabforward locomotive, 1st thing
I noticed was, and this is nothing to do with the 3DTS chaps when
going up the grade the water rises when in reality it should fall
in the glass or in the Cabforward case the figures representing the
water level, one of the quirks in the physics.........Rick

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Rick,An easy test on the boiler level apparantly working backwards would be to run a conventional steamer tender first on a train and see if the same thing happens.

Supergoods

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I got that feeling the same result will be seen Ian.........Rick

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I do not have the cab forward, however out of interest I tested the following theory on a conventional steam locomotive.If you change the .eng file parameter BoilerLength from a positive to a negative value, this reverses the gauge and lets the sim process the gauge values as if it were in the smoke box, thus giving a correct result in the cab forward.I suspect there will probably be some other parameters that may require this also to get proper action in a layout Kuju never dreamed about.

Supergoods

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Good one Ian that'll make 3DTS day...........Rick

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'...so the coefficient for normal rail will be less than 25%....'
~20% for 2 Cylinder engines < 3 Cylinder engines < 25%.
The reciprocating steam cylinders do not develop a constant force like electric engines, so 2 cylinder engines have less tractive effort as a comparable 3 cylinder engine of the same layout and weight. ( or in other words the 3cylinders are easiyer to control if the wheel-spin limit is reached ) But maintainance and the cranked driver axle are the pitfall. UP 9000s are prominent examples of that design.

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This is all very good info for this Christmas I will be getting some tools for MSTS and C&O 614 is high on my list of things to do on my Christmas break from school I know it will not be finished but I can start it.
But my question is Yankee15 what do you think of the SP&S700 in the file Library with a consist of prototypical type weight and length it climbs up MSTS'S junk Marias Pass at a slow speed without stopping so is this loco set up for the real physics or is it wrong to?

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Every loco which can climb Kujus Marias pass with a prototypical consist has wrong physics.
Large steamer can only manage somewhat limited grades. Not out of a lack of power but due to boiler design. The BigBoy was build for maximum grades of ~ 2.2%. Kuju and Marias3.1 use steeper grades.

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