[vince]

scottb613, on 20 February 2015 - 10:26 AM, said:

Hi Folks,

First off - appreciate all the input...
:naughty:

Seems like we have two different opinions voiced...

1) My freight car physics might be messed up - and - that could very be... I believe I got them with Bob Bodoin with his "Plainsman" blessing... LOL - but - it wouldn't be the first time I've messed something up...

2) The other is the forces might be a bit out of whack on ORTS...

I have no way of knowing which is the case...

I did try upgrading the brakes to the Pro Cast Iron version included with Route Righter - and - same deal - 1% brake on a 2.4% grade is like throwing out a boat anchor...

These are the values I updated and my full WAG file is attached...

        Comment ( 70t railcar  Cast Iron Brake Shoe Equipped Max Braking values by Bill Prieger.  Additional
        braking parameters contributed by Jean-Louis Chauvin.  "Percentage Braking" theory provided generously by Rich Evarts. )
    BrakeEquipmentType( "Handbrake, Triple_valve, Auxilary_reservoir, Emergency_brake_reservoir" )
    BrakeSystemType( "Air_single_pipe" )
    MaxBrakeForce( 0.1346kN )

    MaxHandbrakeForce( 30.2kN )
    NumberOfHandbrakeLeverSteps( 100 )

    EmergencyBrakeResMaxPressure( 90 )
    TripleValveRatio( 2.5 )
    MaxReleaseRate( 1.86 )
    MaxApplicationRate( 0.9 )
    MaxAuxilaryChargingRate( 1.684 )
    EmergencyResCapacity( 2.604 )
    EmergencyResChargingRate( 1.684 )
    BrakeCylinderPressureForMaxBrakeBrakeForce( .50 )

WrxPRR1hop55-LD.wag

Regards,
Scott

BrakeCylinderPressureForMaxBrakeBrakeForce( .50 ) seems a bit off as that value '.50' gets you full brake force with _any _ application.

Darn pesky decimal points! :rolleyes:

vince

[markus_GE]

That´s also one of the things that are NOT right with the template files I used in Route Riter, and that also Scott must have applied to his WAG(s) in question.

Cheers, Markus

[scottb613]

Morn'n Folks,

Thanks for all the additional help - I did fix the decimal - but - my cars still stop on a dime... I also tried different locomotives - no change - - - however - - - when I changed out Coal Hoppers for Dick Cowen's - the train behaved normally on the hill... So whatever issue is definitely my Coal Hopper - although - it still doesn't explain why my car behaves "normally" in MSTS... This seems to prove it's not a localized setting issue in ORTS either...

I've done a stare and compare on the two WAG files - my PRR set and Dick Cowen's LN set...


LN WORKING HOPPER

	Friction (
		528.4N/m/s		-0.10		 1.6mph		1.437N/m/s		1.900
		5.1N/rad/s		  1		-1rad/s		    0			  1
		)
	FreightAnim ( "2B-H-Coal.s" 1 1 )
	
	BrakeEquipmentType ( "Handbrake, Triple_valve, Emergency_brake_reservoir, Auxilary_reservoir" )
	BrakeSystemType ( "Air_single_pipe" )
	MaxHandbrakeForce ( 23.6kN )
	NumberOfHandbrakeLeverSteps ( 100 )
	TripleValveRatio ( 2.5 )
	EmergencyResCapacity ( 2.0631 )
	EmergencyResVolumeMultiplier ( 1.461 )
	EmergencyBrakeResMaxPressure ( 90 )
	EmergencyResChargingRate ( 0.23 )
	MaxAuxilaryChargingRate ( 0.23 )
	MaxBrakeForce ( 20.0kN )
	BrakeCylinderPressureForMaxBrakeBrakeForce ( 50 )
	MaxApplicationRate ( 0.49 )
	MaxReleaseRate ( 0.93 )

PRR BROKEN HOPPER - ORIGINAL "PLAINSMAN"

    Friction (
        100N/m/s        1        -1mph        0        1
        5.1N/rad/s        1        -1rad/s        0        1
    )
 
 
    )
 
    BrakeEquipmentType( "Handbrake, Triple_valve, Auxilary_reservoir, Emergency_brake_reservoir" )
    BrakeSystemType( "Air_single_pipe" )
    MaxBrakeForce( 50kN )
 
    MaxHandbrakeForce( 35kN )
    NumberOfHandbrakeLeverSteps( 100 )
 
    TripleValveRatio( 2.5 )
    MaxReleaseRate( 15 )
    MaxApplicationRate( 25 )
    MaxAuxilaryChargingRate( 5 )
    EmergencyResCapacity( 7 )
    EmergencyResChargingRate( 5 )
    EmergencyBrakeResMaxPressure( 90 )
    BrakeCylinderPressureForMaxBrakeBrakeForce( 50 )

PRR BROKEN HOPPER - ROUTE RITER MODS

    Friction (
        100N/m/s        1        -1mph        0        1
        5.1N/rad/s        1        -1rad/s        0        1
    )
 
 
    )
 
    Comment ( 70t railcar  Cast Iron Brake Shoe Equipped Max Braking values by Bill Prieger.  Additional braking parameters contributed by Jean-Louis Chauvin.  "Percentage Braking" theory provided generously by Rich Evarts. )
	
    BrakeEquipmentType( "Handbrake, Triple_valve, Auxilary_reservoir, Emergency_brake_reservoir" )
    BrakeSystemType( "Air_single_pipe" )
    MaxBrakeForce( 0.1346kN )

    MaxHandbrakeForce( 30.2kN )
    NumberOfHandbrakeLeverSteps( 100 )

    EmergencyBrakeResMaxPressure( 90 )
    TripleValveRatio( 2.5 )
    MaxReleaseRate( 1.86 )
    MaxApplicationRate( 0.9 )
    MaxAuxilaryChargingRate( 1.684 )
    EmergencyResCapacity( 2.604 )
    EmergencyResChargingRate( 1.684 )
    BrakeCylinderPressureForMaxBrakeBrakeForce( 50 )

I also took values out of ORTS with both trains.


LN WORKING CONSIST INFO


PRR BROKEN CONSIST INFO





LN WORKING BRAKE INFO


PRR BROKEN BRAKE INFO





LN WORKING FORCE INFO


PRR BROKEN FORCE INFO





Now the most obviously different suspect value between the two WAG files is MaxBrakeForce which was mentioned previously to check...

LN Working: MaxBrakeForce ( 20.0kN )
PRR Broken: MaxBrakeForce( 0.1346kN )

The other interesting screens to note are the "FORCE" screens..

LN Working: 24% Brake = 2434 lbf per car
PRR Broken: 01% Brake = 4892 lbf per car

Is the MaxBrakeForce out to lunch ? My original "Plainsman" version had closer values but still didn't work ?

Thanks...

Regards,
Scott

[copperpen]

The Pro templates that come with Route Riter are specifically developed for running in MSTS, where for some unknown and arcane reason they actually work. I modify mine by moving the decimal point two places right in MaxBrakeForce and BrakeCylinderPressureForMaxBrakeBrakeForce . This works quite well in practice as the Pro force figures are lower than standard anyway.

Looking at the PRR BROKEN HOPPER original the MaxBrakeForce is too high. The PRR BROKEN HOPPER Route Riter mod version has the MaxBrakeForce way too low and in fact should be running down hill out of control unless the engine MaxBrakeForce is far too high. AAR figures are 50% to 65% of locomotive gross weight for MaxBrakeForce at 50PSI. A 6 axle engine would probably attract the higher value, so the F3 would be looking at a MaxBrakeForce of around 50Kn. With the hoppers set at 14kN you might be somewhere in the ballpark with slowing the train instead of stopping it on the hill. You will definitely need more than a 1% set with those figures. If the train gets away, then adjust the locomotive MaxBrakeForce up a wee bit and try again.

[Genma Saotome]

copperpen, on 21 February 2015 - 10:37 AM, said:

The Pro templates that come with Route Riter are specifically developed for running in MSTS, where for some unknown and arcane reason they actually work.

Lots of controlled testing for results.

Shouldn't the same values come closer in OR to being right than they are at present? No code to follow, I know, but something isn't right.

[Lindsayts]

copperpen, on 21 February 2015 - 10:37 AM, said:

The Pro templates that come with Route Riter are specifically developed for running in MSTS, where for some unknown and arcane reason they actually work. I modify mine by moving the decimal point two places right in MaxBrakeForce and BrakeCylinderPressureForMaxBrakeBrakeForce . This works quite well in practice as the Pro force figures are lower than standard anyway.

Looking at the PRR BROKEN HOPPER original the MaxBrakeForce is too high. The PRR BROKEN HOPPER Route Riter mod version has the MaxBrakeForce way too low and in fact should be running down hill out of control unless the engine MaxBrakeForce is far too high. AAR figures are 50% to 65% of locomotive gross weight for MaxBrakeForce at 50PSI. A 6 axle engine would probably attract the higher value, so the F3 would be looking at a MaxBrakeForce of around 50Kn. With the hoppers set at 14kN you might be somewhere in the ballpark with slowing the train instead of stopping it on the hill. You will definitely need more than a 1% set with those figures. If the train gets away, then adjust the locomotive MaxBrakeForce up a wee bit and try again.

One has to be carefull here, in locomotive specs as specifed usually for machines of USA origin,there are ____TWO_____ Maxbrakeforce figures, the ones thats specfied as a percentage of locomotive weight is the total CYLINDER force on the brake shoes.

As specfied in other posts the total brake force for standard rail vehicles cannot far excide 10 percent of the axle load, IMPORTANT NOTE, THIS MEANS YOU. This is not some arbitrary figure plucked out of the air, its limitation enforced by nature and as Dr Feynman said, NATURE CANNOT BE FOOLED.

Most hoppers as they vary so much in weight are fitted with a device in the brake system that senses weight and the hopper switchs to a higher brake force when loaded so such vehicles ALWAYS require to wag files with differing brake forces. For 100ton hopper a Max brake force of say 50Kn when loaded and say 10Kn or less unloaded.

Lindsay

[Genma Saotome]

Here is an early perspective on the issue dating from 1918. Pay no attention to the page that you land on... it's the search string that got me to the book... scroll down about 34-35 pages).

Their take on it was all MaxBrakeForce() should be computed on the basis of the empty car, thereby ensuring the wheels would not slide. The rule of thumb was 70% of the empty car weight was what you should aim for.

Of course later studies took a different perspective but it is interesting to see that even 100 years ago the basic problem of braking was understood... but how to get the optimal answer was still elusive.

There are some formulas present comparing different kinds of brake show applications... the text begins on page 96 with diagrams and formulas following. It might be worthwhile to examine.

[Genma Saotome]

I came across something else of interest: For a train it's steel wheels on steel rails. For comparing braking performance to an automobile his is roughly equivalent to ordinary rubber tires on ice. No wonder it takes so long for them to stop.

[scottb613]

Hi Folks,

I am using the same locomotive and both the working and broken consists... In addition when I switched from BLW F9's to 3DT F9's there was no real discernible change - the working stayed working and the broken stayed broken...

Yeah - with the value set so low - I don't understand why the braking force was more than double at a fraction of the brake setting... Maybe the extremely small number is doing something wacky...

It seems while both BLW engines in my test are F9's - they have slightly different braking values set.

ENGINE 1

    BrakeEquipmentType ( "Triple_valve, Auxilary_reservoir, Emergency_brake_reservoir" )

    BrakeSystemType ( "Air_single_pipe" )
    MaxBrakeForce ( 195.43kN )

    TripleValveRatio ( 2.5 )
    MaxReleaseRate ( 1.9 )
    MaxApplicationRate ( 0.95 )
    MaxAuxilaryChargingRate ( 0.842 )
    EmergencyResCapacity ( 4.1262 )
    EmergencyResChargingRate ( 0.842 )
    EmergencyResVolumeMultiplier ( 1.461 )
    EmergencyBrakeResMaxPressure ( 90 )
    BrakeCylinderPressureForMaxBrakeBrakeForce ( 70 )

ENGINE 2

    BrakeEquipmentType ( "Triple_valve, Auxilary_reservoir, Emergency_brake_reservoir" )

    BrakeSystemType ( "Air_single_pipe" )
    MaxBrakeForce ( 195.43kN )

    TripleValveRatio ( 2.5 )
    MaxReleaseRate ( 0.93 )
    MaxApplicationRate ( 0.45 )
    MaxAuxilaryChargingRate ( 0.842 )
    EmergencyResCapacity ( 2.604 )
    EmergencyResChargingRate ( 0.842 )
    EmergencyBrakeResMaxPressure ( 90 )
    BrakeCylinderPressureForMaxBrakeBrakeForce ( 70 )

Also - here is the actual locomotive pack if anyone is interested - it's free...

http://www.valleypas...les/L&NFree.htm

Regards,
Scott

[copperpen]

The MaxBrakeForce line for those is way to high according to the v4.5 physics set by Bob Boudoin. He rates the F3A at 45kN which is pretty close to my suggested 50kN. F9 in v4.8 physics set is 45.9kN MaxBrakeforce.