Open Rails - Standard Resistance Force Parameters

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

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Index

Standard Resistance

Curve Resistance and Speed Limit

Tunnel Resistance


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
Standard Resistance
This section describe the parameters used to define the standard resistance forces on the train.
ORTSBearingType ( x )WAGDescribes the type of bearing fitted to the wheelsets on the wagon.TextAs per wagon specification.
x = Roller - standard roller bearing,
x = Low - low friction bearing,
x = Friction - friction or journal (plain) bearing.
NewORTSBearingType ( Friction )
ORTSDavis_A ( x )WAGDavis Constant A.Force - N, kN, lbf, lb
Default - N
As per wagon specifications.
(FCalc is used to calculate standard resistance values.)
NewORTSDavis_A ( 502.8N )
ORTSDavis_A ( 502.8lb )
ORTSDavis_B ( x )WAGDavis Constant B.Resistance - N/m/s, lbf/mph
Default - N/m/s
As per wagon specifications.
(FCalc is used to calculate standard resistance values.)
NewORTSDavis_B ( 1.5465N/m/s )
ORTSDavis_B ( 1.5465lbf/mph )
ORTSDavis_C ( x )WAGDavis Constant C.ResistanceDavisC - Nm/s^2, lbf/mph^2
Default - Nm/s^2
As per wagon specifications.
(FCalc is used to calculate standard resistance values.)
NewORTSDavis_C ( 1.43Nm/s^2 )
ORTSDavis_C ( 1.43lbf/mph^2 )
ORTSBearingType ( x )WAGBearing typeRoller, Friction, Low
Default - Roller
As per Wagon SpecsNewORTSBearingType ( Roller )
NB: leave out if not known, or a friction bearing
ORTSDriveWheelWeight ( x )ENGTotal weight on the locomotive driving wheelsMass - lbs, kg, t, t-uk, t-us
Default - kg
As per loco specsNewORTSDriveWheelWeight ( 2.12t )
ORTSDriveWheelWeight ( 4000.0lb )
ORTSDriveWheelWeight ( 2000.0kg )
NB: can be left out if not known
Curve Resistance and Speed Limit
This section describe the parameters used to define the curve resistance and superelevation forces on the train.
CentreOfGravity ( x y z )WAGDescribes the centre of gravity for the vehicle.Distance - m, cm, mm, km, in, ft, in/2
Default - m
As per wagon specifications.
(Measuring CoG)
Distance from central reference point,
x = distance "across train",
y = height above track,
z = distance "along train".
ExistingCentreOfGravity ( 0.0m 2.0m 0.0m )
ORTSTrackGauge ( x y )WAGTrack gauge.Distance - m, cm, mm, km, in, ft, in/2
Default - m
Note - must have both parameters x & y
As per track specifications.NewORTSTrackGauge ( 4ft 8.5in )
ORTSTrackGauge ( 1.0m 435.0mm )
ORTSRigidWheelbase ( x y )WAGFixed wheelbase of bogie or steam locomotive.Distance - m, cm, mm, km, in, ft, in/2
Default - m
Note - must have both parameters x & y
As per track specifications.NewORTSRigidWheelbase ( 0.0ft 56in )
ORTSRigidWheelbase ( 0.0m 900.0mm )
ORTSUnbalancedSuperelevation ( x )WAGCant deficiency specifies the additional speed that a train can travel around a curve without exceeding passenger comfort. Tilt trains for example have higher cant deficiences.Distance - m, cm, mm, km, in, ft, in/2
Default - m
As per wagon specifications.
Typically between 0 & 12 inches.
NewORTSUnbalancedSuperelevation ( 6in )
ORTSTrackSuperElevation ( x1 y1 .. xn yn)TRKTrack superelevation for different radii curves.x = curve radius (in metres), y = superelevation (in mm).
As many x,y pairs may be included in this parameter as desired.
As per track design specifications.NewORTSTrackSuperElevation ( 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 )
Tunnel Resistance
This section describe the parameters used to define the tunnel resistance when a train goes through a tunnel.
ORTSSingleTunnelArea ( x )TRKCross section area of single track tunnel.AreaDefaultFT2 - ft^2, m^2
Default - ft^2
As per track standards.NewORTSSingleTunnelArea ( 27.0m^2 )
ORTSSingleTunnelArea ( 2225.0ft^2 )
ORTSDoubleTunnelArea ( x )TRKCross section area of double track tunnel.AreaDefaultFT2 - ft^2, m^2
Default - ft^2
As per track standards.NewORTSDoubleTunnelArea ( 45.0m^2 )
ORTSDoubleTunnelArea ( 2225.0ft^2 )
ORTSSingleTunnelPerimeter ( x )TRKPerimeter of single track tunnel.Distance - m, cm, mm, km, in, ft, in/2
Default - m
As per track standards.NewORTSSingleTunnelPerimeter ( 21.3m )
ORTSSingleTunnelPerimeter ( 65.0ft )
ORTSDoubleTunnelPerimeter ( x )TRKPerimeter of double track tunnel.Distance - m, cm, mm, km, in, ft, in/2
Default - m
As per track standards.NewORTSDoubleTunnelPerimeter ( 21.3m )
ORTSDoubleTunnelPerimeter ( 65.0ft )

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