Prototypical Data

To ensure accurate performance of locomotives it is important to find as much prototypical data as possible, as well as understanding how the locomotive is likely to behave.

It is important to understand the units of measure that you are working in, and make sure that they are correctly recorded in the ENG and WAG files. For example, by default mass in WAG and ENG files is in metric tons. A metric ton is 1000kg (or 2,204lbs), US tons are 2,000lb, whereas UK tons are 2,240lbs. Thus using the wrong mass value can start to create problems. Units of measure should always be included in all parameters for confirmation, eg Mass ( 30.0 t-uk). If no units are entered then metric tonnes will be assumed by OR.

This information may be gleaned from a number of locations and put together to establish a view of how the locomotive will 'behave' under different operational conditions.

ENG and WAG files can be set by using known prototype information. See the 'Useful Links' section for a list of known information sources.

The accuracy of performance for various pieces of rolling stock within OR very much depends on the correct:

  • Identification of enough prototypical data to accurately specify the physics model for the stock and its expected performance
  • Formatting and inputting of data into the ENG and WAG files.

Once this data has been correctly entered into OR it is important to test the performance of the stock to ensure that the actual performance provides a realistic representation of the expected performance. There may be differences in performance of steam locomotives compared to diesel or electric locomotives. Even the performance between the same classes of steam locomotive may vary, and therefore it is recommended that compromises will need to be made and as such, it is recommended that a 'best fit' approach be aimed for.

For best and most realistic operation, it is also important to ensure that rolling stock used in test consists is set to 'standard' parameters. For example the brake operation settings should be consistent and similar in all pieces of stock as this will provide a consistent performance when testing. For this reason a set of standard test wagons has been created, which may be of assistance, or alternatively the tester may make their own set to a standard that they have chosen.

When testing it is also important to try and limit the number of variables (or things that can go wrong) to a smaller number as possible. Thus it is recommended that only one or two items at a time be tested at one time. In the case of a steam locomotive it is recommended that the tender be tested first and then the locomotive as this will limit the number of variables.

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Typical Prototype Data for Locomotives

Below is an example of the type of information that you will need to find to specify your locomotive correctly.

Loco Data Sheet

Useful Links

Standard Steam Locomotive Specifications - Has most of the standard specifications for steam locomotives, including evaporation and grate areas.

Wikipedia - D50 Class - try searching for the specific class of locomotive to see if the specifications exist on wikipedia.