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.
If you wish to provide any feedback on this page, please use the contact page. It would be great to have some feedback as this helps to ensure the accuracy of the information and models.
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 ) |
| 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 ) |
| 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 ) |
| 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 ) |
| 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 ) |