Open Rails Brakes - Standard Air Brake Parameters

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

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Index

Wagon Brake Information

Locomotive Brake Information - Compressor, Reservoir and 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.
retainer_3_position - a 3 position retaining valve is fitted.
retainer_4_position - a 4 position retaining valve is fitted. This meant for freight wagons only. Only a either a 3 or 4 position retainer is meant to be selected.
vacuum_brake - a vacuum brake is fitted.
triple_valve - a standard triple valve is fitted.
graduated_release_triple_valve - a triple valve that permits partial releasing of the brakes.
ep_brake - an electrically control brake system is fitted. Release and application of the brakes are independently controlled.
ecp_brake - Same as "ep_brake".
auxilary_reservoir - air tank used for normal service brake applications. This is required for all brake systems.
emergency_brake_reservoir - air tank used for emergency applications. This is optional.
distributor - electronic or computer controller on the vehicle that can be set to independently control any parameter of the braking system.
Existing BrakeEquipmentType( "Triple_valve, Auxilary_reservoir" )
BrakeSystemType ( x )WAGDescribes the type of brake system fitted to the wagon.TextAir_single_pipe - One pipe controls and supplies the air brakes.
Air_twin_pipe - Two pipes are used. One to control the brakes, the other to charge the reserviors.
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.
ECP - The brakes are controlled by a computer or complex elctrical control system.
EP - The brakes are a combination of standard air brakes and electrical control signals.
Air_piped - The vehcile has no powered brakes. It only passes on the train pipe pressure for air brakes.
Vacuum_piped - The vehcile has no powered brakes. It only passes on the train pipe pressure for vacuum brakes.
ExistingBrakeSystemType ( "Air_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)
EmergencyRes VolumeMultiplier ( x )WAGRatio of emergency reservoir compare to auxiliary reservoir. (R = EmerRes / AuxRes)MultiplierAs per brake system specifications.ExistingEmergencyRes VolumeMultiplier ( 1.0 )
TripleValveRatio ( x )WAGRatio of the brake cylinder and the auxilary reservoir volumes.MultiplierAs per brake system specifications. Typically on most braking systems this is 2.5.ExistingTripleValveRatio ( 2.5 )
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 )
MaxAuxilaryChargingRate ( x )WAGMaximum rate that the auxiliary resevoir can be refilled at.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications. Typically the auxiliary reservoir will equalize with the main reservoir, within seconds.ExistingMaxAuxilaryChargingRate ( 20.0 )
EmergencyResChargingRate ( x )WAGMaximum rate that the emergency resevoir can be refilled at.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications. Typically the emergency reservoir will equalize with the main reservoir, within seconds.ExistingEmergencyResChargingRate ( 20.0 )
EmergencyResCapacity ( x )WAGVolume of emergency reservoir.VolumeDefaultFT3 - ft^3, in^3, m^3, l, g-uk, g-us
Default - ft^3
As per brake system specifications. (Note this parameter is required, as the auxilairy reservoir volume is calculated form it. To calculate the size of the auxilairy reservoir, firts calculate the size of the brake cylinder first)ExistingEmergencyResCapacity ( 1.792ft^3 )
BrakeCylinderPressureFor MaxBrakeBrakeForce ( x )WAGPressure needed in the brake cylinder for maximum braking force.Pressure - psi, kPa, bar, inHg
Default - psi
As per brake system specifications.ExistingBrakeCylinderPressureFor MaxBrakeBrakeForce ( 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 )
ORTSBrakeShoeFriction ( x, y )WAGCoefficient of friction for brakeshoe.x = speed in kph
y = brakeshoe friction
As per brake system specifications.New ORTSBrakeShoeFriction ( 0.0 0.49 ....... 104.6 0.288)
Locomotive Brake Information - Compressor, Reservoir and General
This section describe the parameters which define the compressor and main reservoir fitted to the locomotive. It appears in the ENG section of the ENG file.
AirBrakesMainMaxAir Pressure ( x )ENGMaximum air pressure in the main air brake reservoir. When this pressure is reached the compressor will automatically stop running.Pressure - psi, kPa, bar, inHg
Default - psi
As per brake system specifications.ExistingAirBrakesMainMaxAir Pressure( 105.0 )
AirBrakesCompressor RestartPressure ( x )ENGPressure below which the compressor will start to recharge the main reservoir.Pressure - psi, kPa, bar, inHg
Default - psi
As per brake system specifications.ExistingAirBrakesCompressor RestartPressure( 90.0 )
AirBrakesMainResVolume ( x )ENGPressure below which the compressor will start to recharge the main reservoir.VolumeDefaultFT3 - ft^3, in^3, m^3, l, g-uk, g-us
Default - ft^3
As per brake system specifications.ExistingAirBrakesMainResVolume ( 20.490ft^3 )
ORTSMainResChargingRate ( x )ENGRecharging rate for main reservoir, depends upon the capacity of the air compressor.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications. (if unknown see brake force calculator)NewORTSMainResChargingRate ( 0.237 )
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 ( 40.0 )
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 ( 0.0833 )
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 )
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.ExistingTrainBrakesController MaxReleaseRate ( 5.0 )
TrainBrakesController MaxQuickReleaseRate ( x )ENGMaximum rate the train brake controller will increase air in the train pipe, under quick brake release.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications.ExistingTrainBrakesController MaxQuickReleaseRate ( 20.0 )
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.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.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 )
TrainBrakesController MinPressureReduction ( x )ENGPressure that will be dropped by a minimum reduction setting on the train brake controller.PressureRateDefaultPSIpS - psi/s, kPa/s, bar/s, inHg/s
Default - psi/s
As per brake system specifications.ExistingTrainBrakesController MinPressureReduction ( 7.0 )
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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