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Motive Power

First, let's define what is meant by "Motive Power": it is any type of steam, diesel, or electric locomotive, traction unit, maintenance vehicle, or other type of self propelled vehicle that runs on rails. This includes everything from speeders to streetcars to Big Boys. It does not include things that are powered models of unpowered vehicles (like hand cars) or unpowered models of powered prototypes (like dummy locomotives).

Contact your Regional AP Manager if you have a question about which category a particular model would fall into.

To qualify for the Master Builder - Motive Power certificate:

1) Build three scale models of railroad motive power, one of which must be scratchbuilt. Motive Power is defined as a locomotive or a self-propelled vehicle.

  1. To qualify as scratchbuilt, the motive power must contain the following scratchbuilt items as applicable:
    Steam Locomotives: frame, boiler, cab, tender frame and body, either valve gear or main and side driving rods.

    Other Motive Power: body, frame, cab, power truck side frame, pantograph or trolley poles where appropriate.

    All models must be capable of self-propulsion on track of the same gauge as the model. Power trains for all models may be commercial motors and gears.

    All models must be super detailed either with scratchbuilt parts or with commercial parts as defined in the Definitions Section.

  2. The following parts are specifically excluded from the scratch built requirement.
    • Motor
    • Gears
    • Drivers and wheels
    • Couplers
    • Light bulbs and electronics
    • Trucks
    • Paint, decals,etc.
    • Bell
    • Marker and classification lights
    • Brake fittings
    • Basic shapes of wood, plastic, metal,etc.

      ("Basic shapes are things that builders of the prototype would have used as raw materials. For example an "I" beam would be a basic shape; a commercial door or window casting would not.)

  3. The term "scratch built" implies that the modeler has done all of the necessary layout and fabrication that produces the final dimensions, appearance, and operating qualities of the model.

    This is a good statement of the intent and spirit of the 'scratch built' requirement. Notice that it does not say that the use of a few commercial detail parts will disqualify the model as being "scratch built". In general, the same standard applies that is used in contest judging: "Completely Scratch built" means that 90% or more of the model by parts count was scratch built. (But you do need to scratch build the listed in requirement 1-A above.) Taking an existing model and modifying it to be a powered model is not considered "scratch building." Examples of this would be taking a passenger car and converting it into a trolley, or a box car and converting it into a box-cab locomotive. These do not meet the definition or the spirit of the term "scratch built" given above.

2) Earn a Merit Award of at least 87.5 points with each of the three scale models of motive power either via an NMRA sponsored contest or AP Merit Award Evaluation.

3) You must submit a Statement of Qualification (SOQ, see below) which includes the following:

  • An attachment giving a detailed description of each model, including:
    • Identification of all scratch built features
    • All commercial components used
    • Materials used in building the model
    • Copies of the plans you used to establish conformity are NOT required, but many people do submit them, and they are reviewed by the person evaluating the model for confomrity.
  • Verification of the Merit Awards (photocopies of the certificates)
  • Photos of the model are helpful, but not required.

Further Information

Contact the AP Committee General Manager at achiev [at] nmra.org, or your Region or Division Achievement Program Manager for more information.

Also refer to the article "Master Builder - Motive Power," NMRA Bulletin, December 1992.

Forms available for this category: