[scottb613]

Hi Folks,

I've been focused on working up a good physics file for an ORTS only Steam Locomotive... I can't seem to get the boiler to run out of steam - no matter what I do... There are only a few values that directly affect steam generation - so I can't see how I screwed this up...

I've played with the advanced ORTS features:

• ORTSBoilerEvaporationRate ( x )

Book Values:

• ORTSSteamBoilerType ( Superheated )
  
• BoilerVolume ( "666.5*(ft^3)" )
  
• ORTSEvaporationArea ( "3607*(ft^2)" )
  
• ORTSSuperheatArea ( "924*(ft^2)" )
  
• MaxBoilerPressure ( 220psi )

As a test I halved the values associated with steam generation (as set in attached ENG file):

• BoilerVolume ( "333.25*(ft^3)" )
  
• ORTSEvaporationArea ( "1803.5*(ft^2)" )
  
• ORTSSuperheatArea ( "462*(ft^2)" )

Nothing I do seems to affect boiler pressure - dramatically - I can run all day with the reverser and regulator wide open (even when the boiler values are halved) - set it and walk away - my steam pressure might drop from a start of 215 to 200 - but even while the steam usage is well into the RED - the boiler pressure starts climbing back up...

When I adjust the aforementioned parameters - it DOES change the point the HUD "Steam Usage" values turn yellow and red - so that aspect (steam generation vs steam usage) does appear to be working... It's just that the values have little or no effect on the boiler pressure...

So - as per Peter's very informative site - I attempted to turn on the "Steam Physics" logging feature to see what's actually happening here... Didn't we used to have a detailed HUD Screen for steam physics at one time ??? So I enabled ORTS logging - enabled Data Logger start logging with sim - enable Data Logger steam physics logging - and I get the nice CSV file - and it's populated with values every 5MPH - however - ALL the columns related to steam physics are blank ?

LOG's and ENG (set to 50% book steam values)
 OpenRailsDump.zip (8.4K)
Number of downloads: 263

Any help - GREATLY - appreciated - I've spent a great deal of time trying to get this to work...

I'll gladly send the full locomotive to anyone that wants to look at this in earnest...

Thanks...

Regards,
Scott

[scottb613]

Hi Folks,

Disregard my logging issue - I had an extra delimeter checked that screwed me up - my original problem still exists though... Going to collect more data...

Regards,
Scott

[darwins]

You have a loco with a huge boiler and a huge firebox. At 20 mph the steam consumption is 60 000 lb/hr - that looks like a rate of working that the loco could sustain for a very long time.

[scottb613]

Hi Folks,

Yeah - maybe it's me - LOL - I can't seem to get consistent results...

Here's several runs logged with the values set back to book - wish it would log every minute...

Same consist - same piece of track...

This is set as well - I'm assuming 10 is the lowest amount of steam produced...

• ORTSBoilerEvaporationRate ( 10 )

 OpenRailsDump (2).zip (1.82K)
Number of downloads: 279

Regards,
Scott

[darwins]

Hi Scott,

For real route testing of performance it would be really good if we could log things either every minute or by distance.

Anyway a quick look over your data (without having information about the performance of the real loco) suggests it is all fairly reasonable.

Getting 2 000 ihp from a steam consumption of 40 000 lb/hr seems about right. The boiler you have should easily sustain that as a steady state.

The largest of British locos could manage that sort of maximum output. With boilers far smaller than your loco (and hand firing!) they could not sustain it though.

Generally US locos had larger boilers and much larger grates in relation to cylinder size - which should mean that it is harder to run short of steam.
Though I think the flip side was dealing with lower quality fuel and longer runs.

ORTS only takes into account the calorific value of the fuel. Other factors might reduce the efficiency of combustion and require a larger firebox - things like size of coal and tendency to clinker.
Formation of ash and clinker might gradually reduce the efficiency of the firebox over time on a long trip.

Regards

Darwin

[steamer_ctn]

As Darwin has suggested this locomotive has a large steam evaporation area, and thus in terms of the power produced by the locomotive the steam produced by the boiler may not be the power limit, but rather the power produced in the cylinders may be the limiting factor. (See the brief explanation under IHP)

To prove the point, reduce the evaporation area to a value say of 1000sq ft and see what the impact is. Make sure that you run the locomotive at the fastest possible speed. For example running at 20mph will use far less steam then running at 50mph.

When testing a locomotive it is good to have in mind a realistic performance standard to test against. What is the standard that you have decided on?

[scottb613]

Hi Darwin/Peter,

Thanks so much for your time, patience, and insights - taking it all onboard...

Hah - figured out one issue that had me confused for a bit - driving around with my boiler pressure pegged at max - then after about 20 to 30 minutes of running it would just die and I couldn’t recover - time and time again - couldn’t figure it out... Ultimately - I think the “max coal per hour” figure I set was way too low - 5000 - up it to 18000 and the issue seems to have gone away - no obvious indications in ORTS to tell me the fire went out though... I guess my fireman just went on a very silent strike (LOL - like my wife when she gets angry) ?

I knocked 20% off the boiler and grate numbers - seems a bit more plausible... I used Peter's load estimator and I’ve been driving around with what your estimator provided for a max load - this locomotive - should be able to pull up a 1.1% grade and I still seem to have plenty of steam with the reduced values...

I tried hand firing as well - but with the information available in ORTS - it seems virtually impossible - we have no indication of how the fire is doing - as we did with the ideal fire mass parameters in MSTS... We really do need a Steam HUD with more information (only the info that would be available to the crew)… I'd love a color coded gauge to tell us how he fire is doing (too much or little air - fire mass from ideal - too much or little fuel)... I don’t think the current smoke color is an accurate representation - is it ?

Right or wrong - with MSTS - as a fireman - boiler pressure was a great indicator - and you could impact trends and influence the direction of the needle by how you controlled the train and regulated the fire... That doesn't seem to be happening here... If the needle is always pegged on max - it’s just a hard way to drive - I’m not saying what’s realistic - as I know you gentlemen know far more than I - on the topic...

Just so I’m clear - unless the value is outlined on your site - Peter - the values are ignored by ORTS ? Boiler effectivity - stuff like that ?

One other thing I've noticed - is most steam locomotives I drive seem way too slippery - now that I have correct Davis numbers - the drag on this locomotive seems right - this massive machine has friction - I'll need to rework the physics files on all those locomotives I routinely drive...

Hah - this is all great stuff - I'll never understand "diesel or toaster guys"...
:p

Here is where I'm at:

SIMISA@@@@@@@@@@JINX0D0t______

Comment ( ########## WAGON SECTION ########## )
Wagon ( 280consolidation 
	Type ( Engine ) 
	WagonShape ( 280consolidation.S ) 
	Size ( 3.26m 4.81m 13.35m )   
	Mass ( 154.85t )
	InertiaTensor ( Box ( 3.26m 4.81m 13.30m ) )
	WheelRadius ( 0.4572m )
	NumWheels (1)
	
Comment ( ##### COUPLING ##### )	
	Coupling ( 
		Type ( Bar )
		Spring ( 
			Stiffness ( 1.2e6N/m 1.2e6N/m ) 
			Damping ( 4.65e5N/m/s 4.65e5N/m/s ) 
			Break ( 1.8e7N 1.8e7N ) 
			r0 ( 0cm 5cm ) 
		) 
		CouplingHasRigidConnection ( 1 ) 
		Velocity ( 0.1m/s ) 
	) 
	Coupling ( 
		Type ( Automatic ) 
		Spring ( 
			Stiffness ( 5.0e5N/m 1.0e7N/m ) 
			Damping ( 1.6e6N/m/s 1.0e7N/m/s ) 
			Break ( 1.2e7N 1.2e7N ) 
			r0 ( 0cm 15cm ) 
		) 
		Velocity ( -0.1m/s ) 
	) 
	
Comment ( ##### ORTS FCALC ##### )
	ORTSBearingType ( Friction )
	ORTSDavis_A ( 3397.47lb )
	ORTSDavis_B ( 4.2570lbf/mph )
	ORTSDavis_C ( 0.240000lbf/mph^2 )
	
	CentreOfGravity ( 0m 2m 0m ) 
	ORTSTrackGauge ( 4ft 8.5in )
	ORTSRigidWheelbase( 17.0ft 5in )
	ORTSUnbalancedSuperelevation ( 6in )
	ORTSTrackSuperElevation ( 0.0 0.00 50.0 0.0 300.0 0.025 400.0 0.025 500.0 0.050 1000.0 0.075 2000.0 0.100 10000.0 0.100 )

Comment ( ##### BRAKES WAGON ##### )
	BrakeEquipmentType ( "Triple_valve, Auxilary_reservoir, Emergency_brake_reservoir, Handbrake" ) 
	BrakeSystemType ( "Air_single_pipe" ) 
	MaxBrakeForce ( 516.63kN )
	MaxHandbrakeForce ( 137.77kN ) 
	TripleValveRatio ( 2.5 ) 
	MaxApplicationRate ( 50 ) 
	MaxReleaseRate ( 50 ) 
	MaxAuxilaryChargingRate ( 20 ) 
	EmergencyResChargingRate ( 20 ) 
	EmergencyResCapacity ( 4.963ft^3 )
	EmergencyBrakeResMaxPressure ( 90 )
	BrakeCylinderPressureForMaxBrakeBrakeForce ( 50 )
	ORTSDirectAdmissionValve (0)
	ORTSAuxilaryResCapacity ( 4.963ft^3 )
	ORTSNumberBrakeCylinders ( 1 )
	ORTSBrakeCylinderSize ( 18in )
	ORTSBrakeShoeFriction ( 0.0 0.5 8.0 0.288 16.1 0.241 24.1 0.211 32.2 0.187 40.2 0.173 48.3 0.161 56.3 0.150 64.4 0.142 72.2 0.139 80.5 0.134 88.5 0.129 96.6 0.125 104.6 0.123 112.7 0.121)
	
Comment ( ##### LIGHTS ##### )
	Lights ( 2 
		Light ( 
			comment ( SPHERE OF LIGHT )
			Type ( 1 ) 
			Conditions ( 
				Headlight ( 3 ) 
				Unit ( 2 ) 
				TimeOfDay ( 2 ) 
			) 
			Cycle ( 0 ) 
			FadeIn ( 0.5 ) 
			FadeOut ( 0.5 ) 
			States ( 1 
				State ( 
					Duration ( 0.0 ) 
					LightColour ( DDF0E296 ) 
					Position ( 0.0 3.75 6.0 ) 
					Transition ( 0 ) 
					Radius ( 300.0 ) 
					Angle ( 25.0 ) 
				) 
			) 
		) 
		Light ( 
			comment ( HEAD LIGHT DISK )
			Type ( 0 ) 
			Conditions ( 
				Headlight ( 3 ) 
				Unit ( 2 ) 
			) 
			FadeIn ( 0.5 ) 
			FadeOut ( 0.5 ) 
			Cycle ( 0 ) 
			States ( 1 
				State ( 
					Duration ( 0.0 ) 
					LightColour ( DDF0E296 ) 
					Position ( 0 3.2 6.00 ) 
					Azimuth ( -5.0 0.0 5.0 ) 
					Transition ( 0 ) 
					Radius ( 0.8 ) 
				) 
			) 
		) 
	) 
	
Comment ( ##### MISC WAGON ##### )
	Sound ( "Mik-h-eng.sms" ) 
	FreightAnim ( crew.s 1 1 ) 
)

Comment ( ########## ENGINE SECTION ########## )
Engine ( 280consolidation 
	Wagon ( 280consolidation ) 
	Type ( Steam )  
	ORTSSteamLocomotiveType ( Simple )
	ORTSDriveWheelWeight ( 283800lb  )
	IsTenderRequired ( 1 ) 
	WheelRadius ( 0.775m )
	NumWheels ( 4 ) 

Comment ( ##### ORTS BOILER -20% ##### )
	ORTSSteamBoilerType ( Superheated )
	ORTSEvaporationArea ( "2885.6*(ft^2)" )
	ORTSSuperheatArea ( "739.2*(ft^2)" )
	MaxBoilerPressure ( 220psi )
	BoilerVolume ( "533.2*(ft^3)" )

Comment ( ##### ORTS BOILER - ADVANCED ##### )	
Comment	( ORTSBoilerEvaporationRate ( 10 ) )

Comment ( ##### ORTS CYLINDER ##### )
	NumCylinders ( 2 )
	CylinderDiameter ( 27in )	
	CylinderStroke ( 32in ) 
	ORTSCylinderEfficiencyRate ( 1.0 )
	
Comment ( ##### ORTS FIRE -20% ##### )
	ORTSFuelCalorific ( 12500btu/lb )
	ORTSGrateArea ( "80.0*(ft^2)" )

Comment ( ##### ORTS FUEL ##### )
	MaxTenderCoalMass ( 32000lb ) 
	MaxTenderWaterMass ( 125000lb )
	ORTSSteamFiremanMaxPossibleFiringRate ( 12000 lb/h )
	SteamFiremanIsMechanicalStoker ( 1.0 )

Comment ( ##### EFFECTS ##### )	
	Effects ( 
		SteamSpecialEffects ( 
			StackFX ( 	0 5.1 3.8
						0 1 0
						0.25
			) 
			WhistleFX ( -0.58 4.65 0
						0 1 0
						0.1
			) 
			SafetyValvesFX ( 	0 4.4 -1.2
								0 1 0
								0.1
			) 
			CylindersFX ( 		1.496 0.464 3.8
								1 0 -0.5
								0.15
			)
			CylindersFX ( 		-1.496 0.464 3.8
								-1 0 -0.5
								0.15
			) 

			Injectors1FX (		0.75 0.28 -6.25
								1 0 -0.5
								0.1
								
			)
			Injectors2FX (		-0.75 0.28 -6.25
								-1 0 -0.5
								0.1
								
			)
			GeneratorFX	( 	-0.7 4.4 -3.77
							0 1 0
							0.06 
			)
			GeneratorFX	( 	-0.7 4.4 -3.77
							0 1 0
							0.06 
			)
		) 
	) 
	
Comment ( ##### BRAKES - COMPRESSOR ##### )       
AirBrakesMainMaxAirPressure( 105.0 )
AirBrakesCompressorRestartPressure( 90.0 )
AirBrakesMainResVolume ( "28.93*(ft^3)" )
ORTSMainResChargingRate( 0.237 )
ORTSBrakePipeChargingRate ( 40.0 )
TrainPipeLeakRate (0.0833)
 
Comment ( ##### BRAKES - AUTOMATIC BRAKE - TRAIN ##### )   
TrainBrakesControllerMaxSystemPressure ( 70 )
TrainBrakesControllerMaxReleaseRate ( 5.0 )
TrainBrakesControllerMaxQuickReleaseRate ( 20.0 )
TrainBrakesControllerMaxApplicationRate ( 2.0 )
TrainBrakesControllerEmergencyApplicationRate ( 30.0 )
TrainBrakesControllerFullServicePressureDrop ( 25.0 )
TrainBrakesControllerMinPressureReduction ( 7.0 )

Comment ( ##### BRAKES - INDEPENDENT BRAKE - ENGINE/TENDER ##### )   
EngineBrakesControllerMaxSystemPressure ( 70 )
EngineBrakesControllerMaxReleaseRate ( 5.0 )
EngineBrakesControllerMaxQuickReleaseRate ( 20.0 )
EngineBrakesControllerMaxApplicationRate ( 2.0 )
EngineBrakesControllerEmergencyApplicationRate ( 30.0 )
EngineBrakesControllerFullServicePressureDrop ( 25.0 )
EngineBrakesControllerMinPressureReduction ( 7.0 )
	
Comment ( ##### PLAYER CONTROLS ##### )
	EngineControllers ( 
		Regulator ( 0 1 0.025 0 
			NumNotches ( 0 
			) 
		) 
		Cutoff ( -0.8 0.8 0.025 0 
			NumNotches ( 0 
			) 
		) 
		Brake_Train ( 0 1 0.025 0.6 
			NumNotches ( 5 
				Notch ( 0 0 TrainBrakesControllerReleaseStart ) 
				Notch ( 0.2 0 TrainBrakesControllerRunningStart ) 
				Notch ( 0.3 0 TrainBrakesControllerSelfLapStart ) 
				Notch ( 0.4 1 TrainBrakesControllerApplyStart ) 
				Notch ( 1 0 TrainBrakesControllerEmergencyStart ) 
			) 
		) 
		Brake_Engine ( 0 1 0.005 1 
			NumNotches ( 5
				Notch( 0.0 0 TrainBrakesControllerFullQuickReleaseStart )
				Notch( 0.25 0 TrainBrakesControllerRunningStart )
				Notch( 0.50 0 TrainBrakesControllerHoldStart )
				Notch( 0.75 0 TrainBrakesControllerFullServiceStart )
				Notch( 1.0 0 TrainBrakesControllerEmergencyStart )
			)
		)
		FireDoor ( 0 1 1 0 
			NumNotches ( 0 
			) 
		) 
		Sanding ( 0 1 0 ) 
		Blower ( 0 1 0.1 0.1 
			NumNotches ( 0 
			) 
		) 
		HeatingTap ( 0 1 0.025 0 
			NumNotches ( 0 
			) 
		) 
		Shovel ( 0 1 0.1 0 
			NumNotches ( 0 
			) 
		) 
		DampersFront ( 0 1 0.1 1 
			NumNotches ( 0 
			) 
		) 
		DampersBack ( 0 1 0.1 0 
			NumNotches ( 0 
			) 
		) 
		Injector1Steam ( 0 1 0 ) 
		Injector2Steam ( 0 1 0 ) 
		Injector1Water ( 0 1 0.2 0 
			NumNotches ( 0 
			) 
		) 
		Injector2Water ( 0 1 0.2 0 
			NumNotches ( 0 
			) 
		) 
		CylinderCocks ( 0 1 0 ) 
		Whistle ( 0 1 0 ) 
		BellToggle ( 0 1 0 ) 
		SmallEjectorOrCompressor ( 0 1 1 ) 
		HeadLights ( 0 1 0 ) 
	)
	
Comment ( ##### MISC ENGINE ##### )
	Sound ( "Mik-h-cab.sms" ) 
	Name ( "Wrx LHR 2-8-0 Consolidation" ) 
	CabView ( sps_700.cvf ) 
	HeadOut ( 1.95 3.5 -6.2 )
	Description ( "The description of the engine that the user will see.\n"+
        " \n" ) 
	EngineOperatingProcedures ( "The operating procedures for the engine.\n"+
        " \n" ) 
)

Regards,
Scott

[scottb613]

steamer_ctn, on 23 March 2019 - 07:04 PM, said:

As Darwin has suggested this locomotive has a large steam evaporation area, and thus in terms of the power produced by the locomotive the steam produced by the boiler may not be the power limit, but rather the power produced in the cylinders may be the limiting factor. (See the brief explanation under IHP)

To prove the point, reduce the evaporation area to a value say of 1000sq ft and see what the impact is. Make sure that you run the locomotive at the fastest possible speed. For example running at 20mph will use far less steam then running at 50mph.

When testing a locomotive it is good to have in mind a realistic performance standard to test against. What is the standard that you have decided on?

Hi Peter,

Sorry - not sure what you meant about standard - I have a PDF with basic performance numbers - but I don’t have any standard...

Regards,
Scott

[copperpen]

Take a look at http://www.coalstone...eam-set/#boiler in particular the ORTSBoilerEfficiency section. Using that parameter you can keep the normal grate, superheater and evap surface figures. The boiler efficiency curve will limit how much heat is put into the boiler by the fire. Using this it is possible to make an engine behave very differently than it would without the curve in place.


It is possible to write an efficiency curve that does affect boiler pressure if the engine is driven hard. I am currently fiddling with one that will not allow me to drive for too long using 45% cutoff and high throttle settings before the boiler pressure goes into freefall. It drops from 220 to 129 in just a couple of minutes once the grate limit has been exceeded for a few minutes and takes quite a while to recover.

[Lindsayts]

A loco of the size specified in the ENG file will have a drawbar HP in the region of 3 to 4000 HP at 50mph, with a steam consumption of around 15lbs per BHP, this figure will vary depending on when the loco was built. Between the 1920's and 1940's american locos improved markedly in eficiency through better pipe work and cylinder design.

Lindsay