Open Rails Brakes - Standard Vacuum Brake Parameters

Aim - this section describes the basic standard physics parameters required to correctly define a vacuum brake in Open Rails Train Simulator.

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Index

Wagon Brake Information

Locomotive Brake Information - General

Locomotive Brake Controller Information

Locomotive Brake Control Valve Information


Note: The default unit of measure (UoM) shown in the "Recommended Input Units" column is the UoM value that OR assumes if no UoM is included in the parameter statement.

ParameterENG or WAGDescriptionRecommended Input UnitsSuggested settingsNew or ExistingTypical Examples
Wagon Brake Information
This section describe the parameters defining the brake equipment fitted to the wagon, carriage, locomotive or tender. In the case of locomotives it appears in the WAG section of the ENG file.
BrakeEquipmentType ( x ) WAG Describes the type of brake equipment fitted to the wagon. Text (Multiple values can be specified) handbrake - a handbrake is fitted.
vacuum_brake - a vacuum brake is fitted.
Existing BrakeEquipmentType( "handbrake, vacuum_brake" )
BrakeSystemType ( x )WAGDescribes the type of brake system fitted to the wagon.TextAir_single_pipe - One pipe controls and supplies the air brakes.
Vacuum_single_pipe - One pipe is used to supply and control the air brakes.
Vacuum_twin_pipe - Two pipes are used. One controls the vacuum brakes, the other supply the vacuum reservior.
Vacuum_piped - The vehcile has no powered brakes. It only passes on the train pipe pressure for vacuum brakes.
ExistingBrakeSystemType ( "Vacuum_single_pipe" )
MaxBrakeForce ( x )WAGThe maximum braking force that is applied to the wagon wheel, includes the coefficient of friction for the brakeshoe.Force - N, kN, lbf
Default - Newtons
As per wagon specifications (if unknown see brake force calculator)ExistingMaxBrakeForce ( 92.153kN )
MaxHandbrakeForce ( x )WAGThe maximum force that is applied to the wagon wheel by the handbrake.Force - N, kN, lbf
Default - Newtons
As per wagon specifications (if unknown see brake force calculator)ExistingMaxHandbrakeForce ( 24.574kN )
ORTSBrakeShoeFriction ( x y )WAGThe coefficient of friction for the brakeshoe acting upon the wheel.x = Factor
y = Speed - kmh
As per brakeshoe specifications.
Note: The corresponding MaxBrakeForce value should be calculated with a coefficient value equal to the zero kmh vale of this curve.
NewORTSBrakeShoeFriction ( 0.0 0.49 ........ 104.6 0.288)
MaxReleaseRate ( x )WAGMaximum rate that the brake cylinder can drop pressure.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications. Typically brake systems can exahust the air in the brake cylinder within seconds, so high values are not unusual.ExistingMaxReleaseRate ( 50.0 )
MaxApplicationRate ( x )WAGMaximum rate that the brake cylinder can drop pressure.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications. Typically the brake cylinder will equalize with the auxilary reservoir within seconds, so high values are not unusual.ExistingMaxApplicationRate ( 50.0 )
BrakePipeVolume ( x )WAGVolume of brake pipe on wagon, including an allowance for brake hose connections between cars.VolumeDefaultFT3 - ft^3, in^3, m^3, l, g-uk, g-us
Default - ft^3
As per brake system specifications (the brake force calculator can assist in calculating this value).NewBrakePipeVolume ( 0.307ft^3 )
ORTSDirectAdmissionValve ( x )WAGCar has direct admission valves fittedIntegerAs per brake system specifications.
0 = not fitted,
1 = fitted
NewORTSDirectAdmissionValve ( 0 )
ORTSAuxilaryResCapacity ( x )WAGVolume of vacuum reservoirVolumeDefaultFT3 - ft^3, in^3, m^3, l, g-uk, g-us
Default - ft^3
As per brake system specifications.NewORTSAuxilaryResCapacity ( 20.0ft^3 )
ORTSNumberBrakeCylinders ( x )WAGNumber of Brake Cylinders on vehicle.IntegerAs per brake system specifications.ExistingORTSNumberBrakeCylinders ( 1 )
ORTSBrakeCylinderSize ( x )WAGDiameter of brake cylinders fitted to vehicleDistance - m, cm, mm, km, in, ft, in/2
Default - m
As per brake system specifications.NewORTSBrakeCylinderSize ( 18in )
Locomotive Brake Information - General
This section describe the parameters which define the brakes fitted to the locomotive. It appears in the ENG section of the ENG file.
VacuumBrakesMinBoilerPressureMaxVacuum ( x )ENGBoiler pressure when maximum vacuum for the small ejector is produced.Pressure - psi, kPa, bar, inHg
Default - psi
As per brake system specifications.ExistingVacuumBrakesMinBoilerPressureMaxVacuum ( 110.0 )
ORTSBrakePipeChargingRate ( x )ENGCharging rate for brake pipe, influences the pressure gradient, or how fast the air can travel to the end of the train.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications.
x > 1000, disables the function. This value can also be set through the option menu.
NewORTSBrakePipeChargingRate ( 40.0InHg/s )
TrainPipeLeakRate ( x )ENGLeakage rate for brake pipe, influences the pressure maintained in brake pipe. Leaking brake pipes can apply brakes.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications.ExistingTrainPipeLeakRate ( 0.0833InHg/s )
ORTSBrakePipeTimeFactor ( x )ENGInfluences the time for brake pressure changes to propogate through the train brake pipe along the length of the train.Time - s, m, h
Default - s
As per train brake system specifications.NewORTSBrakePipeTimeFactor ( 0.003 )
ORTSBrakeServiceTimeFactor ( x )ENGInfluences the time for the brake pipe pressure to drop and equate to the equalising reservoir pressure under normal operation.Time - s, m, h
Default - s
As per train brake system specifications.NewORTSBrakeServiceTimeFactor ( 1.009 )
ORTSBrakeEmergencyTimeFactor ( x )ENGInfluences the time for the brake pipe pressure to drop and equate to the equalising reservoir pressure under emergency operation.Time - s, m, h
Default - s
As per train brake system specifications.NewORTSBrakeEmergencyTimeFactor ( 0.1 )
ORTSBrakePipeDischargeTimeMult ( x )ENGControls propagation decrease time along train pipe as vacuum is destroyed, ie when brakes appliedFactorAs per train brake system specifications.NewORTSBrakePipeDischargeTimeMult ( 1.5 )
BrakesTrainBrakeType ( x )ENGIndicates type of train brake implemented.set to "vacuum_single_pipe_eq" or "vacuum_single_pipe" as appropriateAs per train brake system specifications.ExistingBrakesTrainBrakeType ( "vacuum_single_pipe_eq" )
VacuumBrakesSmallEjectorUsageRate ( x )ENGThe rate that the small ejector uses steam from the boiler when it is on. Referenced to 120psi steam pressure. (Steam locomotives only).MassRateDefaultLBpH - lb/hr
Default - lb/h
As per train brake system specifications.ExistingVacuumBrakesSmallEjectorUsageRate ( 300.0 )
VacuumBrakesLargeEjectorUsageRate ( x )ENGThe rate that the large ejector uses steam from the boiler when it is on. Referenced to 120psi steam pressure. (Steam locomotives only).MassRateDefaultLBpH - lb/hr
Default - lb/h
As per train brake system specifications.ExistingVacuumBrakesLargeEjectorUsageRate ( 650.0 )
VacuumBrakesHasVacuumPump ( x )ENGA vacuum pump or exhauster is fitted to the locomotiveInteger -
0 = No, 1 = Yes
Default - No
As per train brake system specifications.ExistingVacuumBrakesHasVacuumPump ( 0 )
ORTSVacuumBrakesMainResVolume ( x )ENGThe volume of the main vacuum brake reservoirVolumeDefaultFT3 - ft^3, in^3, m^3, l, g-uk, g-us
Default - ft^3
As per train brake system specifications.NewORTSVacuumBrakesMainResVolume ( 200.0 )
ORTSVacuumBrakesMainResMaxVacuum ( x )ENGThe maximum vacuum in the main vacuum brake reservoir. When this pressure is reached the exhauster will automatically stop running.Pressure - psi, kPa, bar, inHg
Default - psi
As per train brake system specifications.NewORTSVacuumBrakesMainResMaxVacuum ( 23.0InHg/s )
ORTSVacuumBrakesExhausterRestartVacuum ( x )ENGThe rate that the large ejector uses steam from the boiler when it is on. Referenced to 120psi steam pressure. (Steam locomotives only).Pressure - psi, kPa, bar, inHg
Default - psi
As per train brake system specifications.NewORTSVacuumBrakesExhausterRestartVacuum ( 21.0InHg/s )
ORTSVacuumBrakesMainResChargingRate ( x )ENGThe rate at which the main vacuum reservoir charges at.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default
As per train brake system specifications.NewORTSVacuumBrakesMainResChargingRate ( 0.2 )
Locomotive Brake Controller Information
This section describe the parameters defining the brake control equipment for the automatic (train brake) and independent (engine) brake. These parameters control the pressure in the brake pipe, which inturn operates the triple valve located on the wagon. They appear in the ENG section of the ENG file. Only the parameters for the automatic brake are shown below, but by substituting the word "Engine" for "Train" at the beginning of each parameter the independent brake can be defined with the same type of parameters.
TrainBrakesController MaxSystemPressure ( x )ENGMaximum pressure that the train brake pipe will operate at for the train brake system.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications.ExistingTrainBrakesController MaxSystemPressure ( 70 )
TrainBrakesController MaxReleaseRate ( x )ENGMaximum rate the train brake controller will increase air in the train pipe, under normal brake release.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications.
(Only required if Equalising Reservoir fitted to brake system)
ExistingTrainBrakesController MaxReleaseRate ( 5.0 )
TrainBrakesController MaxApplicationRate( x )ENGMaximum rate the train brake controller will release air from the train pipe, under normal brake application.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications.
(Only required if Equalising Reservoir fitted to brake system)
ExistingTrainBrakesController MaxApplicationRate ( 2.0 )
TrainBrakesController EmergencyApplicationRate( x )ENGMaximum rate the train brake controller will release air from the train pipe, under emergency brake application.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications.
(Only required if Equalising Reservoir fitted to brake system)
ExistingTrainBrakesController EmergencyApplicationRate ( 30.0 )
TrainBrakesController FullServicePressureDrop ( x )ENGPressure drop resulting from a full service application of the train brake controller.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications.ExistingTrainBrakesController FullServicePressureDrop ( 25.0 )
Locomotive Brake Control Valve Information
This section describes some of the parameters used to define the brake control valve used by the locomotive driver. They appear in the ENG section of the ENG file. This statement includes a 'brakecontroller' for each notch position on the brake control valve. For asn indication of the type of brakecontrollers to use for different brake valves refer to the brakecontrollers page.
ControlName ( w x y z ) ENGDescribes a notched control valve.MulitpliersAs per brake system specifications.
w - minimum value of valve
x - maximum value of valve
y - step value of valve
z - default value (setting this values determines the starting position of the brakes)
ExistingBrake_Train ( 0 1 0.01 0.25

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