Open Rails Steam Locomotive Standard Physics Parameters
Aim - this section describes the basic standard physics parameters required to correctly define a steam locomotive in Open Rails Train Simulator. For advanced physics parameters see the Advanced Steam Setting Parameters.
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Index
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 |
|---|---|---|---|---|---|---|
| General Information | ||||||
| Type ( x ) | ENG | Describes the type of locomotive | Text | Steam, Diesel, Electric | Existing | Type ( Steam ) |
| ORTSSteamLocomotiveType ( x ) | ENG | Describes the type of steam locomotive | Text | Simple, Compound, Geared | New | ORTSSteamLocomotiveType ( Simple ) |
| WheelRadius ( x ) | ENG | Radius of drive wheels | Distance - m, cm, mm, km, in, ft, in/2 Default - m | As per loco specs | Existing | WheelRadius ( 0.648m ) WheelRadius ( 36in ) |
| ORTSNumberDriveAxles ( x ) | ENG | Number of driven axles on the locomotive. | Number | As per locomotive Specs | New | ORTSNumberDriveAxles ( 4 ) |
| ORTSNumberAxles ( x ) | WAG | Number of axles on the wagon. | Number | As per wagon Specs | New | ORTSNumberAxles ( 4 ) |
| ORTSDriveWheelWeight ( x ) | ENG | Total weight on the drive wheels of the locomotive. | Mass - lbs, kg, t, t-uk, t-us Default - kg | As per loco specs. | New | ORTSDriveWheelWeight ( 109.5t-uk ) |
| IsTenderRequired ( x ) | ENG | Indicates whether the locomotive is a tender or tank type of locomotive | Text | As per loco specs: 0 = no tender req'd 1 = tender req'd | Existing | IsTenderRequired ( 1 ) |
| Boiler Parameters | ||||||
| ORTSSteamBoilerType ( x ) | ENG | Describes the type of boiler | Text | Saturated, Superheated | New | ORTSSteamBoilerType ( Saturated ) |
| BoilerVolume ( x ) | ENG | Volume of boiler | VolumeDefaultFT3 - ft^3, in^3, m^3, l, g-uk, g-us Default - ft^3 | This parameter is not overly critical, and where an actual value is not available, use the appropriate calculator for your engine type. | Existing | BoilerVolume ( 220.0ft^3 ) BoilerVolume ( 110.0m^3 ) |
| ORTSEvaporationArea ( x ) | ENG | Boiler evaporation area | AreaDefaultFT2 - ft^2, m^2 Default - ft^2 | As per loco specs, or where unknown, use the appropriate calculator for your engine type. | New | ORTSEvaporationArea ( 2198.0ft^2 ) ORTSEvaporationArea ( 194.0m^2 ) |
| MaxBoilerPressure ( x ) | ENG | Max boiler working pressure (Gauge pressure) | PressureDefaultPSI - psi, bar, kPa, inhg Default - psi | As per loco specs | Existing | MaxBoilerPressure ( 200psi ) MaxBoilerPressure ( 200kPa ) |
| ORTSSuperheatArea ( x ) | ENG | Superheating heating area | AreaDefaultFT2 - ft^2, m^2 Default - ft^2 | As per loco specs | New | ORTSSuperheatArea ( 2198.0ft^2 ) ORTSSuperheatArea ( 194.0m^2 ) |
| MaxSteamHeatingPressure ( x ) | ENG | Max pressure in steam heating system for passenger carriages. | PressureDefaultPSI - psi, bar, kPa, inhg Default - psi | As per loco specs. NB: Normally < 100psi. | Existing | MaxSteamHeatingPressure ( 80.0psi ) |
| ORTSBoilerSurfaceArea ( x ) | ENG | External surface area of boiler and firebox for the purposes of radiation of heat losses to the atmosphere. | AreaDefaultFT2 - ft^2, m^2 Default - ft^2 | As per loco specs. | New | ORTSBoilerSurfaceArea ( 475.0ft^2 ) |
| ORTSFractionBoilerInsulated ( x ) | ENG | Describe the fraction of the boiler which has a layer of insulation over it. | Number ( < 1.0 ) | As per loco specs. | New | ORTSFractionBoilerInsulated ( 0.86 ) |
| ORTSHeatCoefficientInsulation ( x ) | ENG | Heat coefficient of insulation fitted to boiler. | (BTU / ((sq. ft.) / hr.)) / (1 (in. / F)) ( Typically a value < 1.0 ) | As per insulation specs. | New | ORTSHeatCoefficientInsulation ( 0.4 ) |
| ORTSSteamLocomotiveFeedwaterSystemType ( x ) | ENG | Type of feedwater system | Text - MotionPump Default - Injector | As per loco specs | New | ORTSSteamLocomotiveFeedwaterSystemType ( MotionPump ) |
| Locomotive Tender Info | ||||||
| MaxTenderWaterMass ( x ) | ENG | Water in tender | Mass - lbs, kg, t, t-uk, t-us Default - kg 1 uk gal = 10lb 1 us gal = 8.34lb | As per loco specs | Existing. (These values should always be present by default, unless the value has been included in the tender file). | MaxTenderWaterMass ( 36500lb ) MaxTenderWaterMass ( 16000kg ) |
| MaxTenderCoalMass ( x ) | ENG | Coal in tender | Mass - lbs, kg, t, t-uk, t-us Default - kg | As per loco specs | Existing. (These values should always be present by default, unless the value has been included in the tender file). | MaxTenderCoalMass ( 13440lb ) MaxTenderCoalMass ( 6000kg ) |
| ORTSMaxTenderWoodMass ( x ) | ENG | Wood in tender | Mass - lbs, kg, t, t-uk, t-us Default - kg | As per loco specs | New. (These values should always be present by default, unless the value has been included in the tender file). | ORTSMaxTenderWoodMass ( 13440lb ) ORTSMaxTenderWoodMass ( 6000kg ) |
| ORTSMaxTenderFuelOilVolume ( x ) | ENG | Oil in tender | Volume - ft^3, in^3, m^3, l, g-uk, g-us, gal, gals Default - l | As per loco specs | New. (These values should always be present by default, unless the value has been included in the tender file). | ORTSMaxTenderFuelOilVolume ( 11000l ) ORTSMaxTenderFuelOilVolume ( 4000gal-us ) |
| ORTSTenderWagonWaterMass ( x ) | WAG | Water in tender | Mass - lbs, kg, t, t-uk, t-us Default - kg 1 uk gal = 10lb 1 us gal = 8.34lb | As per loco specs | New. (These values can be used to overwrite the above values, or instead of them). | ORTSTenderWagonWaterMass ( 36500lb ) ORTSTenderWagonWaterMass ( 16000kg ) |
| ORTSTenderWagonCoalMass ( x ) | WAG | Coal in tender | Mass - lbs, kg, t, t-uk, t-us Default - kg | As per loco specs | New. (These values can be used to overwrite the above values, or instead of them). | ORTSTenderWagonCoalMass ( 13440lb ) ORTSTenderWagonCoalMass ( 6000kg ) |
| ORTSTenderWagonWoodMass ( x ) | WAG | Wood in tender | Mass - lbs, kg, t, t-uk, t-us Default - kg | As per loco specs | New. (These values can be used to overwrite the above values, or instead of them). | ORTSTenderWagonWoodMass ( 13440lb ) ORTSTenderWagonWoodMass ( 6000kg ) |
| ORTSTenderWagonFuelOilVolume ( x ) | WAG | Oil in tender | Volume - ft^3, in^3, m^3, l, g-uk, g-us, gal, gals Default - l | As per loco specs | New. (These values can be used to overwrite the above values, or instead of them). | ORTSTenderWagonFuelOilVolume ( 11000l ) ORTSTenderWagonFuelOilVolume ( 4000gal-us ) |
| Fire | ||||||
| ORTSGrateArea ( x ) | ENG | Locomotive fire grate area | AreaDefaultFT2 - ft^2, m^2 Default - ft^2 | As per loco specs | New | ORTSGrateArea ( 2198.0ft^2 ) ORTSGrateArea ( 194.0m^2 ) |
| ORTSFuelOilHeatingRequired ( x ) | ENG | Fuel oil heating required | Where, 1 = true, 0 = false. | As per loco specs. | New | ORTSFuelOilHeatingRequired ( 1 ) |
| ORTSFuelOilSpecificGravity ( x ) | ENG | Specific gravity of fuel oil | Number | As per loco specs. | New | ORTSFuelOilSpecificGravity ( 1.021 ) |
| ORTSSteamLocomotiveFuelType ( x ) | ENG | Fuel type of locomotive | Text - Wood, Oil, Coal Default - Coal | As per loco specs | New | ORTSSteamLocomotiveFuelType ( Wood ) ORTSSteamLocomotiveFuelType ( Oil ) |
| ORTSFuelCalorific ( x ) | ENG | Calorific value of fuel | Energy Density - btu/lb, kj/kg, j/g Default - kj/kg | Internet search - for coal use a default value of 13700 btu/lb | New | ORTSFuelCalorific ( 13700btu/lb ) ORTSFuelCalorific ( 33400kj/kg ) |
| ORTSSteamFiremanMaxPossibleFiringRate( x ) | ENG | Maximum fuel rate that fireman can shovel in an hour | Mass - lbs, kg, t, t-uk, t-us Default - kg | Use following as defaults: UK - 3000lb/h US - 5000lb/h Aus - 4200lb/h | New - alternate value to MSTS | ORTSSteamFiremanMaxPossibleFiringRate( 4200lb/h ) ORTSSteamFiremanMaxPossibleFiringRate( 2000kg/h ) |
| SteamFiremanIsMechanicalStoker ( x ) | ENG | Indicates that the locomotive has a mechanical stoker, and hence a large rate of coal feed. | Factor | As per loco specs: 0 = no stoker 1 = stoker | Existing | SteamFiremanIsMechanicalStoker ( 1.0 ) |
| Steam Cylinder | ||||||
| NumCylinders ( x ) | ENG | Number of steam cylinders | Factor | As per loco specs | Existing | NumCylinders ( 2 ) |
| CylinderStroke ( x ) | ENG | Length of cylinder stroke | Distance - m, cm, mm, km, in, ft, in/2 Default - m | As per loco specs | Existing | CylinderStroke ( 26in ) CylinderStroke ( 0.8m ) |
| CylinderDiameter ( x ) | ENG | Diameter of cylinder | Distance - m, cm, mm, km, in, ft, in/2 Default - m | As per loco specs | Existing | CylinderDiameter ( 21in ) CylinderDiameter ( 0.6m ) |
| LPNumCylinders ( x ) | ENG | Number of steam LP cylinders (Compound locomotive only) | Factor | As per loco specs | New | LPNumCylinders ( 2 ) |
| LPCylinderStroke ( x ) | ENG | Length of LP cylinder stroke (Compound locomotive only) | Distance - m, cm, mm, km, in, ft, in/2 Default - m | As per loco specs | New | LPCylinderStroke ( 26in ) LPCylinderStroke ( 0.8m ) |
| LPCylinderDiameter ( x ) | ENG | Diameter of LP cylinder (Compound locomotive only) | Distance - m, cm, mm, km, in, ft, in/2 Default - m | As per loco specs | New | LPCylinderDiameter ( 21in ) LPCylinderDiameter ( 0.6m ) |
| Locomotive Gearing | ||||||
| ORTSSteamGearRatio ( a, b ) | ENG | Ratio of gears | Value | As per loco specs | New | ORTSSteamGearRatio ( 2.55, 0.0 ) |
| ORTSSteamMaxGearPistonRate ( x ) | ENG | Max speed of piston in ft/min | Value only | As per loco specs | New | ORTSSteamMaxGearPistonRate ( 650 ) |
| ORTSSteamGearType ( x ) | ENG | Indicates whether the locomotive has fixed gearing or selectable gearing | Fixed, Select | As per loco specs | New | ORTSSteamGearType ( Fixed ) |
| ORTSWheelCrankAngleDifference ( a b c d ) | ENG | Indicates the difference in the rotation points of each of the cranks. | Angle - rad, deg. Default - rad | As per loco specs, where a,b,c,d are the angle from a reference of 0deg. Each value represents a cylinder, so for example a 2 cylinder definition will only require 2 values. | New | ORTSWheelCrankAngleDifference ( 0deg 120deg 240deg ) |