Open Rails Basic Diesel Parameters

Aim - this section describes the basic "optimal" settings for diesel related parameters in Open Rails (OR) ENG files.

This page references information for the British Rail Class D16/2 (#10203) diesel electric locomotive which has been used as a demonstration and test model. The documents indicated in the Useful References at the bottom of this page were used as the principal reference sources. A diesel test model based upon this locomotive has been configured for use in Open Rails.

For realistic performance it is important to set the Open Rails diesel parameters to calculate the correct values.

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

Index

Key Open Rails Parameters for Diesel Locomotives

Setting Diesel Locomotive Traction Motor Section

Sample Diesel Code

Useful References


Key Open Rails Parameters for Diesel Locomotives

The key parameters that impact upon the performance of a diesel locomotive are described on the following web page.

Standard Parameters for Diesel ENG and WAG Files (updated Nov 2019)

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Setting Diesel Locomotive Traction Motor Section

In a BASIC ENG file configuration some simple information can be entered to specify the rail forces used by the locomotive. Alternatively if desired, an ADVANCED configuration can be created by building a Tractive Force Curve Table.

The traction motor information conatins information about the forces applied to the rails by the diesel locomotive. Typically a locomotive will be specified by the tractive forces as shown in this example:

Maximum Force (typically Starting Force) = 50,000lbf
Maximum Continuous Force = 30,000lbf
Speed of Maximum Continuous Force = 19.5mph

The Rail HP can then be calculated as described using one of the formulas on the Diesel Physics page.

Using the above values, and the formula we can calculate the Rail Hp as 1560hp. These values can then be entered into the traction motor section of the ENG file, as demonstrated below.

If a value of adhesion is quoted with the above values, that is different to 0.33, it maybe necessary to create and add a Curtius-Kniffler Adhesion Table.

When configuring AC diesel locomotives, the power be a lot higher then the rated power of the locomotive, and in this case it should be considered the "apparent" power output of the traction motors.

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Sample Diesel Code

The code parameters shown below are those that are required to define a diesel locomotive within Open Rails. They should be set using known parameters so that the optimal accuracy of operation can be obtained.

A diesel test model with sample ENG files can be downloaded from the CTN test stock page.

When inserting values in these parameters it is recommended that you use the appropraite units of measure.

Comment ( *** General Information *** )
WheelRadius ( 0.5461m )
Sanding ( 25mph )
NumWheels ( 6 )
ORTSDriveWheelWeight ( 109.5t-uk )

Comment ( *** Diesel Prime Mover (Engine) *** )
Type ( Diesel )
ORTSDieselEngineMaxPower ( 1260kW )
MaxDieselLevel( 1180g-uk )
MaxTemperature ( 120degF )
MaxOilPressure ( 90 )
DieselUsedPerHourAtMaxPower ( 75.2g-uk )
DieselUsedPerHourAtIdle ( 25.5g-uk )
DieselEngineIdleRPM( 450 )
DieselEngineMaxRPM( 850 )
DieselEngineMaxRPMChangeRate( 40 )

Comment ( *** Diesel Engine - Exhaust Effects *** )
DieselSmokeEffectInitialMagnitude( 1.7 )
DieselSmokeEffectMaxMagnitude( 2.2 )
DieselSmokeEffectInitialSmokeRate( 0.2 )
DieselSmokeEffectMaxSmokeRate( 10 )

Comment ( *** Traction Motor *** )
MaxPower ( 1560kW )
MaxForce ( 50000lb )
MaxContinuousForce ( 30000lb )
ORTSSpeedOfMaxContinuousForce ( 19.5mph )
MaxVelocity ( 90mph )
MaxCurrent ( 2600A )

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Useful References

British Railways Test Report 2000 HP Diesel Electric Locomotive #10203

British Railways Class D16/2 Diesel Electric Locomotive #10203

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