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Hello!
Would anyone be able to identify or share examples of working twin pipe air brakes for reference? I have attempted to follow the various guides here and at the CTN website to set up my braking systems but notice an inconsistency with what I imagine would be prototypical behavior. The auxiliary reservoir never seems used in a twin pipe system. All braking pressure change seems to come from the brake pipe. The auxilliary remains fully charged all the time even during emergency braking. Is this expected / prototypical?
Changing the system to single pipe seems to then apply accordingly, with the brake pipe and auxlliary dropping pressure together....
Working Air Twin Pipe Brake Examples
Looking for examples
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#1
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Posted 06 September 2020 - 01:53 AM
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Posted 06 September 2020 - 05:38 AM
With a twin pipe system, one pipe is Brake pipe reservoir, one pipe is the brake pipe.
When brakes are applied, only the brake pipe will be reduced, and the aux reservoir is fed from the brake pipe reservior pipe.
When brakes are applied, only the brake pipe will be reduced, and the aux reservoir is fed from the brake pipe reservior pipe.
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Posted 07 September 2020 - 11:24 AM
Yes I just realized that after posting. I had my main reservoir set much higher than the brake line (as prototypical on the Indian system I am modeling) hence never saw the auxiliary pressure ever change as it follows the brake line pressure.
The Indian railways braking system has the brake line set at 70psi, the auxiliary and feed line set at 84 psi, while the main reservoir is at 130psi. Would a configuration like this be able to be simulated in open rails?
The Indian railways braking system has the brake line set at 70psi, the auxiliary and feed line set at 84 psi, while the main reservoir is at 130psi. Would a configuration like this be able to be simulated in open rails?
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Posted 07 September 2020 - 12:19 PM
Hello,
At the moment you can set brake pipe at 70 psi and reservoir pipe at 84 psi - but only with the main reservoir also at 84 psi.
Alternatively you can set brake pipe at 70 psi and main reservoir at 130 psi - but then the reservoir pipe would also be at 130 psi.
To date there is no "reducing valve" between the main reservoir and the reservoir pipe in Open Rails - so you will probably need to fake the reading on one of the cab gauges for the moment.
Similarly it is not possible at the moment to "overcharge" the air brake pipe in an air brake system.
Here is a working example of a twin pipe brake system.
(1) in the wagon section
(2) In the engine section:
(3) The engine controllers (This is an older type like the Westinghouse controllers of 1960s to 1980s):
At the moment you can set brake pipe at 70 psi and reservoir pipe at 84 psi - but only with the main reservoir also at 84 psi.
Alternatively you can set brake pipe at 70 psi and main reservoir at 130 psi - but then the reservoir pipe would also be at 130 psi.
To date there is no "reducing valve" between the main reservoir and the reservoir pipe in Open Rails - so you will probably need to fake the reading on one of the cab gauges for the moment.
Similarly it is not possible at the moment to "overcharge" the air brake pipe in an air brake system.
Here is a working example of a twin pipe brake system.
(1) in the wagon section
Comment ( ******************************* Brakes *********************************************
Included in this section - Type, Force, Reservoir, Applicatiion, Release. etc
************************************************************************************ )
BrakeEquipmentType ( Distributor, Auxilary_reservoir, Handbrake )
BrakeSystemType( Air_twin_pipe )
MaxBrakeForce ( 297kN ) Comment ( brake @ 82.5% WWO, coefficient of friction 0.50 )
MaxHandbrakeForce ( 70kN )
EmergencyResVolumeMultiplier ( 1.0 )
TripleValveRatio ( 2.5 )
MaxReleaseRate ( 9.0psi/s ) Comment ( * Locomotive brake cylinder 68 to 5 psi in 7.8s air passenger mode * )
MaxApplicationRate ( 20.0psi/s ) Comment ( * Locomotive brake cylinder 0 to 70 psi in 3.5s in air passenger mode * )
MaxAuxilaryChargingRate ( 20.0 )
EmergencyResChargingRate ( 20.0 )
BrakeCylinderPressureForMaxBrakeBrakeForce ( 70.0 )
EmergencyResCapacity ( 2.064ft^3 )
BrakePipeVolume ( 0.43ft^3 )
ORTSBrakeShoeFriction ( 0.0 0.50 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 ( Cast Iron Brakeshoes )(2) In the engine section:
Comment (*************************** Brake System *********************************************
Included in this section - Compressor, Reservoir, Application rates, etc
**************************************************************************************)
Comment ( *** Braking system *** )
BrakesEngineBrakeType( "Air_twin_pipe" )
BrakesTrainBrakeType( "Air_twin_pipe" )
BrakesEngineControllers( "Independent, Train" )
Comment ( == Compressor, Reservoir and General == )
AirBrakesMainMaxAirPressure( 90 )
AirBrakesCompressorRestartPressure( 75 )
ORTSBrakePipeChargingRate ( 300 )
AirBrakesMainResVolume( 35ft^3 )
ORTSMainResChargingRate ( 0.575 )
TrainPipeLeakRate ( 0.0833 )
Comment ( == Automatic Brake valve - Train == )
TrainBrakesControllerMaxSystemPressure( 5.0bar )
TrainBrakesControllerMaxQuickReleaseRate( 46psi/s )
TrainBrakesControllerMaxReleaseRate( 46psi/s )
TrainBrakesControllerMaxApplicationRate( 4.2psi/s )
TrainBrakesControllerEmergencyApplicationRate( 60psi/s )
TrainBrakesControllerFullServicePressureDrop( 24 )
TrainBrakesControllerMinPressureReduction( 6 )
ORTSDoesBrakeCutPower ( 1 )
ORTSBrakeCutsPowerAtBrakePipePressure ( 46psi )
ORTSBrakeRestoresPowerAtBrakePipePressure ( 60psi )
Comment ( == Independent Brake valve - Engine )
EngineBrakesControllerMaxSystemPressure( 70 )
EngineBrakesControllerMaxReleaseRate( 10 )
EngineBrakesControllerMaxApplicationRate( 10 )
EngineBrakesControllerFullServicePressureDrop( 1.65bar )
EngineBrakesControllerMinPressureReduction( 0.40bar )(3) The engine controllers (This is an older type like the Westinghouse controllers of 1960s to 1980s):
Brake_Train ( 0 1 0.1 0.2 NumNotches ( 4 Notch ( 0.0 0 TrainBrakesControllerFullQuickReleaseStart ) Comment ( RELEASE - sprung position - overcharges train pipe ) Notch ( 0.1 0 TrainBrakesControllerReleaseStart ) Comment ( RUNNING ) Notch ( 0.2 1 TrainBrakesControllerContinuousServiceStart ) Notch ( 1.0 0 TrainBrakesControllerEmergencyStart ))) Comment ( add ANTI SLIP brake ) Brake_Engine ( 0 1 0.1 0.0 NumNotches( 1 Notch( 0 1 EngineBrakesControllerContinuousServiceStart ) ) )
#5
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Posted 07 September 2020 - 12:43 PM
No Triple Valve, Darwins?
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Posted 07 September 2020 - 08:48 PM
Distributor serves the function of triple valve in modern air brake system - hence
TripleValveRatio ( 2.5 )
The HuD will show the triple valve (distributor) as Release, Apply, Emergency...
TripleValveRatio ( 2.5 )
The HuD will show the triple valve (distributor) as Release, Apply, Emergency...
#7
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Posted 08 September 2020 - 01:23 AM
ahh.... now everything makes sense! I've been wondering about this for two years :sweatingbullets:
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Posted 08 September 2020 - 01:57 AM
This is an example of a more modern stepped brake controller
Ignore the fact that it says 'EP' as this controller works fine for regular twin pipe air brakes (as well as for EP type brakes).
The engine section that goes with this one:
A bit like your request - this loco should have 140 psi in the main reservoir, but only 100 max in the reservoir pipe.
Brake_Train ( 0 1.0 0.01 0.2 NumNotches ( 9 Notch ( 0 0 TrainBrakesControllerFullQuickReleaseStart ) Comment ( REL - Release = Should overcharge ATP to 5.40 bar ) Notch ( 0.01 0 TrainBrakesControllerReleaseStart ) Comment ( RUN - Running = 5.00 bar ) Notch ( 0.02 0 TrainBrakesControllerEPApplyStart ) Comment ( 1 INIL - Initial = 4.60 bar ) Notch ( 0.16 0 TrainBrakesControllerEPApplyStart ) Comment ( 2 = 4.35 bar ) Notch ( 0.40 0 TrainBrakesControllerEPApplyStart ) Comment ( 3 = 4.10 bar ) Notch ( 0.65 0 TrainBrakesControllerEPApplyStart ) Comment ( 4 = 3.85 bar ) Notch ( 0.80 0 TrainBrakesControllerEPApplyStart ) Comment ( 5 = 3.60 bar ) Notch ( 0.99 0 TrainBrakesControllerEPApplyStart ) Comment ( 6 FULL SERV - Full Service = 3.35 bar ) Notch ( 1.00 0 TrainBrakesControllerEmergencyStart )Comment ( EMGCY - Emergency ))) Brake_Engine ( 0 1 0.3 0 NumNotches ( 3 Notch ( 0 0 EngineBrakesControllerReleaseStart ) Notch ( 0.3 0 EngineBrakesControllerHoldStart ) Notch ( 0.6 0 EngineBrakesControllerFullServiceStart )))
Ignore the fact that it says 'EP' as this controller works fine for regular twin pipe air brakes (as well as for EP type brakes).
The engine section that goes with this one:
Comment ( *** Braking system *** )
BrakesEngineBrakeType( "Air_twin_pipe" )
BrakesTrainBrakeType( "Air_twin_pipe" )
BrakesEngineControllers( "Independent, Train, Blended" )
Comment ( == Compressor, Reservoir and General == )
AirBrakesMainMaxAirPressure( 140 ) Comment ( Max pressure in MR pipe should be 100 psi )
AirBrakesCompressorRestartPressure( 118 )
ORTSBrakePipeChargingRate ( 300 )
AirBrakesMainResVolume( 35ft^3 )
ORTSMainResChargingRate ( 0.575 )
TrainPipeLeakRate ( 0.0833 )
Comment ( == Automatic Brake valve - Train == )
TrainBrakesControllerMaxSystemPressure( 5.0bar )
TrainBrakesControllerMaxQuickReleaseRate( 46psi/s ) Comment (* 0 to 70 psi in 1.5s in air passenger mode *)
TrainBrakesControllerMaxReleaseRate( 46psi/s ) Comment (* 0 to 70 psi in 1.5s in air passenger mode *)
TrainBrakesControllerMaxApplicationRate( 4.2psi/s ) Comment (* 70 to 45 psi in 6.0s in air passenger mode *)
TrainBrakesControllerEmergencyApplicationRate( 60psi/s ) Comment (* 70 to 0 psi in 3.5s in air passenger mode *)
TrainBrakesControllerFullServicePressureDrop( 24 )
TrainBrakesControllerMinPressureReduction( 6 )
ORTSDoesBrakeCutPower ( 1 )
ORTSBrakeCutsPowerAtBrakePipePressure ( 46psi )
ORTSBrakeRestoresPowerAtBrakePipePressure ( 60psi )
DynamicBrakesMaximumForce( 120kN )
DynamicBrakesCutInSpeed( 25 )
DynamicBrakesMaxAirBrakePressure ( 72.5 )
DynamicBrakesDelayTimeBeforeEngaging ( 1 )
DynamicBrakesNumberOfControllerNotches( 10 )
DynamicBrakeHasAutoBailOff( 1 )
ORTSDynamicBrakeBlendingForceMatch ( 1 )
Comment ( == Independent Brake valve - Engine )
EngineBrakesControllerMaxSystemPressure( 70 )
EngineBrakesControllerMaxReleaseRate( 10 )
EngineBrakesControllerMaxApplicationRate( 10 )
EngineBrakesControllerFullServicePressureDrop( 1.65bar )
EngineBrakesControllerMinPressureReduction( 0.40bar )A bit like your request - this loco should have 140 psi in the main reservoir, but only 100 max in the reservoir pipe.
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Posted 17 September 2020 - 03:42 AM
darwins, on 08 September 2020 - 01:57 AM, said:
This is an example of a more modern stepped brake controller
Ignore the fact that it says 'EP' as this controller works fine for regular twin pipe air brakes (as well as for EP type brakes).
The engine section that goes with this one:
A bit like your request - this loco should have 140 psi in the main reservoir, but only 100 max in the reservoir pipe.
Brake_Train ( 0 1.0 0.01 0.2 NumNotches ( 9 Notch ( 0 0 TrainBrakesControllerFullQuickReleaseStart ) Comment ( REL - Release = Should overcharge ATP to 5.40 bar ) Notch ( 0.01 0 TrainBrakesControllerReleaseStart ) Comment ( RUN - Running = 5.00 bar ) Notch ( 0.02 0 TrainBrakesControllerEPApplyStart ) Comment ( 1 INIL - Initial = 4.60 bar ) Notch ( 0.16 0 TrainBrakesControllerEPApplyStart ) Comment ( 2 = 4.35 bar ) Notch ( 0.40 0 TrainBrakesControllerEPApplyStart ) Comment ( 3 = 4.10 bar ) Notch ( 0.65 0 TrainBrakesControllerEPApplyStart ) Comment ( 4 = 3.85 bar ) Notch ( 0.80 0 TrainBrakesControllerEPApplyStart ) Comment ( 5 = 3.60 bar ) Notch ( 0.99 0 TrainBrakesControllerEPApplyStart ) Comment ( 6 FULL SERV - Full Service = 3.35 bar ) Notch ( 1.00 0 TrainBrakesControllerEmergencyStart )Comment ( EMGCY - Emergency ))) Brake_Engine ( 0 1 0.3 0 NumNotches ( 3 Notch ( 0 0 EngineBrakesControllerReleaseStart ) Notch ( 0.3 0 EngineBrakesControllerHoldStart ) Notch ( 0.6 0 EngineBrakesControllerFullServiceStart )))
Ignore the fact that it says 'EP' as this controller works fine for regular twin pipe air brakes (as well as for EP type brakes).
The engine section that goes with this one:
Comment ( *** Braking system *** )
BrakesEngineBrakeType( "Air_twin_pipe" )
BrakesTrainBrakeType( "Air_twin_pipe" )
BrakesEngineControllers( "Independent, Train, Blended" )
Comment ( == Compressor, Reservoir and General == )
AirBrakesMainMaxAirPressure( 140 ) Comment ( Max pressure in MR pipe should be 100 psi )
AirBrakesCompressorRestartPressure( 118 )
ORTSBrakePipeChargingRate ( 300 )
AirBrakesMainResVolume( 35ft^3 )
ORTSMainResChargingRate ( 0.575 )
TrainPipeLeakRate ( 0.0833 )
Comment ( == Automatic Brake valve - Train == )
TrainBrakesControllerMaxSystemPressure( 5.0bar )
TrainBrakesControllerMaxQuickReleaseRate( 46psi/s ) Comment (* 0 to 70 psi in 1.5s in air passenger mode *)
TrainBrakesControllerMaxReleaseRate( 46psi/s ) Comment (* 0 to 70 psi in 1.5s in air passenger mode *)
TrainBrakesControllerMaxApplicationRate( 4.2psi/s ) Comment (* 70 to 45 psi in 6.0s in air passenger mode *)
TrainBrakesControllerEmergencyApplicationRate( 60psi/s ) Comment (* 70 to 0 psi in 3.5s in air passenger mode *)
TrainBrakesControllerFullServicePressureDrop( 24 )
TrainBrakesControllerMinPressureReduction( 6 )
ORTSDoesBrakeCutPower ( 1 )
ORTSBrakeCutsPowerAtBrakePipePressure ( 46psi )
ORTSBrakeRestoresPowerAtBrakePipePressure ( 60psi )
DynamicBrakesMaximumForce( 120kN )
DynamicBrakesCutInSpeed( 25 )
DynamicBrakesMaxAirBrakePressure ( 72.5 )
DynamicBrakesDelayTimeBeforeEngaging ( 1 )
DynamicBrakesNumberOfControllerNotches( 10 )
DynamicBrakeHasAutoBailOff( 1 )
ORTSDynamicBrakeBlendingForceMatch ( 1 )
Comment ( == Independent Brake valve - Engine )
EngineBrakesControllerMaxSystemPressure( 70 )
EngineBrakesControllerMaxReleaseRate( 10 )
EngineBrakesControllerMaxApplicationRate( 10 )
EngineBrakesControllerFullServicePressureDrop( 1.65bar )
EngineBrakesControllerMinPressureReduction( 0.40bar )A bit like your request - this loco should have 140 psi in the main reservoir, but only 100 max in the reservoir pipe.
Excellent stuff, thank you very much for sharing your examples! I have already set up the brakes as earlier mentioned (main res @ 130 psi, brake pipe/Aux @ 70psi), which works fine other than the Aux practically never dropping in pressure due to the higher than prototypical feed pipe.
I guess thats a restriction to live with til any further improvements on the brake code are implemented.
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Posted 25 April 2022 - 03:25 AM
I'd also like to share my current set up:
Comment (*** CP2600 Braking system ***) BrakesEngineBrakeType ( "Air_twin_pipe" ) BrakesTrainBrakeType ( "Air_twin_pipe" ) BrakesEngineControllers ( "Independent, Train, Hand" ) BrakeCutsPowerAtBrakeCylinderPressure ( 4.8bar ) #( 69.618psi ) ORTSBrakeRestoresPowerAtBrakePipePressure ( 5bar ) #( 72.518psi ) ORTSDoesBrakeCutPower ( 1 ) Comment (*** Compressor, Reservoir and General ***) AirBrakesMainMaxAirPressure ( 8.5bar ) #( 123.282psi verificado em manual de conducao ) AirBrakesCompressorRestartPressure ( 7.5bar ) #( 108.778psi verificado em manual de conducao ) AirBrakesMainResVolume ( 1000l ) #( 35---17.657ft^3 ) ORTSBrakePipeChargingRate ( 20.684bar/s ) #( 300---40.611psi ) ORTSMainResChargingRate ( 0.047bar/s ) #( 0.682psi/s ) TrainPipeLeakRate ( 0.005bar/s ) #( 0.0725psi/s valor na CG costuma ser 0,3 bar/mn. Valor na CP deve ser 0,15 bar/min ) ORTSBrakePipeTimeFactor ( 0.003 ) ORTSBrakeServiceTimeFactor ( 1.009s ) ORTSBrakeEmergencyTimeFactor ( 0.100s ) ORTSBrakeCutsPowerAtBrakePipePressure ( 3.17bar ) #( 46psi ) ORTSBrakeRestoresPowerAtBrakePipePressure ( 4.13bar ) #( 60psi ) Comment (*** Automatic Brake valve - Train ***) TrainBrakesControllerMaxSystemPressure ( 5.0bar ) #( 72.518psi ) TrainBrakesControllerMaxReleaseRate ( 3.172bar/s ) #( 46---6.092psi/s ) TrainBrakesControllerMaxQuickReleaseRate ( 3.172bar/s ) #( 46---6.092psi/s ) TrainBrakesControllerMaxApplicationRate ( 0.29bar/s ) #( 4.2---12.473psi/s ) TrainBrakesControllerEmergencyApplicationRate ( 4.137bar/s ) #( 60----24.946psi/s ) TrainBrakesControllerFullServicePressureDrop ( 1.8bar ) #( 26.107psi ) TrainBrakesControllerMinPressureReduction ( 0.4bar ) #( 5.802psi ) ORTSTrainBrakesControllerMaxOverchargePressure ( 5.4bar ) Comment (Maximum overcharge) ORTSTrainBrakesControllerOverchargeEliminationRate ( 0.0027bar/s ) Comment (The leakage rate that drops to 5 bar in 150s) Comment (*** Independent Brake valve - Engine ***) EngineBrakesControllerMaxSystemPressure ( 5.0bar ) #( 72.518psi ) EngineBrakesControllerMaxReleaseRate ( 0.69bar/s ) #( 10---6.092psi/s ) EngineBrakesControllerMaxQuickReleaseRate ( 0.84bar/s ) #( 12.14psi/s ) EngineBrakesControllerMaxApplicationRate ( 0.69bar/s ) #( 10---12.473psi/s ) EngineBrakesControllerEmergencyApplicationRate ( 1.72bar/s ) #( 24.946psi/s ) EngineBrakesControllerFullServicePressureDrop ( 2.0bar ) #( 26.107psi ) EngineBrakesControllerMinPressureReduction ( 0.4bar ) #( 5.802psi )
Brake_Train ( 0 1 0.025 1 NumNotches ( 3 Notch ( 0.0 0 TrainBrakesControllerReleaseStart ) Notch ( 0.1 1 TrainBrakesControllerContinuousServiceStart ) Notch ( 1.0 0 TrainBrakesControllerFullServiceStart ) ) ) Brake_Engine ( 0 1 0.025 0.5 NumNotches ( 3 Notch( 0.0 0 EngineBrakesControllerReleaseStart ) Notch( 0.1 1 EngineBrakesControllerContinuousServiceStart ) Notch( 1.0 0 EngineBrakesControllerFullServiceStart ) ) ) Brake_Hand ( 0 1 0.0125 0 NumNotches( 0 ) )