Open Rails Steam Locomotive Advanced Physics Parameters
Aim - this section describes the advanced physics parameters required to correctly define a steam locomotive in Open Rails Train Simulator. For standard physics parameters see the Standard Steam Setting Parameters.
It is recommended that these settings are changed with great care only, as they may significantly impact the performance of the locomotive.
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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.
| Parameter | ENG or WAG | Description | Recommended Input Units | Suggested settings | New or Existing | Typical Examples |
|---|---|---|---|---|---|---|
| ORTSBoilerEvaporationRate ( x ) | ENG | Amount of steam generated by locomotive | Value | As per locomotive specifications. Typically Steam Gnererated (lbs/hr) = Evap Rate x Grate Area (ft^2) Value can be between 10 and 15. | New | ORTSBoilerEvaporationRate ( 15.0 ) |
| ORTSMaxIndicatedHorsepower ( x ) | ENG | Maximum IHP of locomotive | Power - W, kW, HP Default - W | As per locomotive specifications. | New | ORTSMaxIndicatedHorsepower ( 2500.0hp ) |
| ORTSMaxSuperheatTemperature ( x ) | ENG | Maximum superheat temperature of locomotive | Default - Fahrenheit | As per locomotive specifications. | New | ORTSMaxSuperheatTemperature ( 280.0 ) |
| ORTSSuperheatCutoffPressureFactor ( x ) | ENG | Factor to vary cutoff pressure (wiredrawing) with speed. Superheated locomotives only | value | As per locomotive MEP specifications. | New | ORTSSuperheatCutoffPressureFactor ( 55.0 ) |
| ORTSCylinderPortOpening ( x ) | ENG | Factor to vary cutoff pressure (wiredrawing) with speed. Saturated locomotives only | value | As per locomotive MEP specifications. | New | ORTSCylinderPortOpening ( 0.05 ) |
| ORTSBoilerEfficiency ( x y) | ENG | Efficiency of boiler. | value | As per loco specs: x = Dry Coal Fired (lbs/sq ft/hr) y = Boiler Efficiency (Fraction, ie 0 - 1) | New | ORTSBoilerEfficiency ( x y ) |
| ORTSBurnRate ( x y ) | ENG | Indicates the rate of coal usage against steam generation. | value | As per loco specs: x = Actual steam evaporation (lb/hr) y = Dry coal used (lbs/hr) | New | ORTSBurnRate ( x y ) |
| ORTSCylinderInitialPressureDrop ( x y ) | ENG | Indicates the drop in pressure between the boiler and the cylinder. | value | As per loco specs: x = Wheel revolutions (rpm) y = Initial to boiler pressure drop factor | New | ORTSCylinderInitialPressureDrop ( x y ) |
| ORTSCylinderBackPressure ( x y ) | ENG | Indicates the back pressure in the steam cylinder as the indicated horsepower rises. | value | As per loco specs: x = Indicated Horsepower (hp) y = Back pressure in psi (atmospheric) | New | ORTSCylinderBackPressure ( x y ) |