Introduction to Model Railroading – Part III

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(You can find Part II of this post here)

Locomotive Power

The prospect of having a dynamic railroad brings us to the last – and arguably, most exciting part of the series! Imagine beautiful little locomotives and coaches moving all over your house – some even complete with lights, sounds and smoke!

The most natural thing to use to power a locomotive would be batteries of course. But given the size of the locomotives (e.g. The Pink Engine locomotives are around 3 cm wide on average), this becomes an extremely challenging task. Remember that apart from batteries, the locomotive needs to house motors and gearing mechanisms to drive the locomotive.

An ingenious solution is to draw power from the tracks!

Basic structure of track

Tracks, Wheels and Bogies

The basic structure of HO track is shown in the graphic above. The metal rails are separated by insulated sleepers. This implies that the two rails are electrically insulated from each other. And if you didn’t know already you will never guess how the power is taken from the tracks by the locomotive! (Or maybe, you will…)

The metal wheels are responsible for taking power from the two rails of the tracks and sending them to the motor and other electrical accessories aboard the locomotive!

Of course, you would have guessed by now that the metal wheels need to be electrically insulated from each other and the good thing is that they usually are! Furthermore, conductive electrical wires called pickups take power from the wheels and send them to the motors etc.

One more thing that is important to note is that the word bogie DOES NOT refer to a coach. If you ask a train engineer or a model railroader he/she will assume that you are talking about the rotating assembly beneath a coach or wagon which holds the wheels. That’s what is shown in the picture above and to the right. Be careful about this terminology.

Electrical Control

The setup till now is indicated in the graphic below. All that is required now is a power supply and controller to supply electricity to the rails and to control the speed of the locomotive.

The complete circuit to be able to feed power to the locomotive from the tracks

The Pink Engine locomotives run off 12V. The wall supply takes 220 volts AC and converts it into 12 volts DC. This moves through the DC controller which can further vary the voltage via a knob, between 0V and 12V – which in turn controls the speed of the locomotive from zero to full speed respectively. The DC controller also includes a directional switch because locomotives locomotives can go in either direction (Duh!) Power is fed from the DC controller to the tracks by a special track known as the terminal track.

And there you have it. A locomotive that you can control and which will bring you endless hours of joy! There is something absolutely mesmerising about watching those things go around a track. Here is one to get you started. If you want a complete trainset, you might want to look here.

Welcome to a new definition of rail-fanning

This concludes our introductory series

Follow TheTrainMaker:

Creator of Indian Railways models. Loves 3D printing and talking!

2 Responses

  1. Kunal

    Hi, I’m visiting back after a while, actually. And I’d this email exchange with you, to build a custom, dynamic layout for myself. I remember “A” saying you’ll be coming up with a blog series on it.
    Well, I’ve gone through the three articles and are enough to get me hooked at the hobby again.

    Though, would’ve liked to see a sample requirement evaluation – say, for an oval track with a siding, to move a locomotive with three coaches (you can choose the minimum required dimensions).
    – how much it cost to build any specimen layout,
    – what all types of tracks will be needed (apart from at least one terminal track),
    – how long it’ll take to finish and the last-minute tweaks,
    – what tasks do I need to do myself (if any) et cetera.
    Do you think you can entertain my request?

    • TheTrainMaker

      Hello Kunal,
      It’s great to see you excited about “The World’s Greatest Hobby”!
      Here are a few pointers to get you started…

      For an oval track complete with a terminal track you can look at You can of course change the length of the straight section by adding more straight track which you should also find in our shop.

      You can make a simple (non-passing) siding by using a turnout which you can find at Note that the straight section of this turnout is 12″ (1 foot), in case you need that information to plan out your layout.

      You’ll have to plan your layout yourself and then it is a simple matter of taking these individual track sections and connecting them together with the rail joiners that are included with every track.

      Hope that helps!

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