Open Rails Units of Measure

Aim - this section describes the standard units of measure (UoM) available in Open Rails Train Simulator. These are the UoM used to input values from the ENG or WAG files.

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Unit of MeasureDescriptionDefault UoMAlternative UoMsTypical Examples
MassDescribes the weight of an objectkglb, t (metric tonne), t-uk
(imperial ton), t-us (us ton)
Mass ( 106t-us )
DistanceDescribes the length or distance between two points or locations.mcm, mm, km, ft, inWheelRadius ( 21.5in )
AreaDescribes the area of an object.m^2ft^2ORTSSuperheatArea ( 295ft^2 )
Volume (of a space)Describes the volume of an object.m^3ft^3, in^3BoilerVolume ( 340ft^3 )
Volume (fluid quantity)Describes the fluid quantity contained by an object.lg-uk (gallons - uk), g-us (gals - us)MaxDieselLevel ( 800g-uk )
TimeDescribes the elapsed time between two, h
CurrentDescribes the current flow in a circuit.AMaxCurrent ( 2700A )
VoltageDescribes the voltage of a circuit.VkV
SpeedDescribes the speed of an object.m/smph, km/hSanding ( 20mph )
Mass Rate of ChangeDescribes the rate of change in mass for an
FrequencyDescribes the frequency of movement of an object.hzrpm, rps
ForceDescribes the force applied to an object.NkN, lbfMaxForce ( 227kN )
PowerDescribes the power of an object.WkW, hpMaxPower ( 2650hp )
PressureDescribes the pressure of an object.psibar, kpa, inhgMaxBoilerPressure ( 250psi )
Pressure rate of changeDescribes the rate of change in pressure of an object.psi/sbar/s, kpa/s, inhg/sTrainPipeLeakRate ( 0.01inhg/s )
Energy DensityDescribes the energy density of an object.kj/kgbtu/lbORTSFuelCalorific ( 13700btu/lb )
TemperatureDescribes the temperature of an object.degcdegf
Davis B CoefficientDescribes the UoM for the Davis B value.ns/mlbf/mph
Davis C CoefficientDescribes the UoM for the Davis C value.Nm/s^2lbf/mph^2
StiffnessDescribes the stiffness.n/mStiffness ( 1e6N/m 2e6N/m )
Rotational InertiaDescribes the inertia due to the rotation of an object.kgm^2
AngleDescribes the angle of an object.raddegORTSMaximumWheelFlangeAngle ( 75deg )