Origins: Power Functions Trains

The LEGO Group has produced train sets since before the advent of the minifigure. Over this long history the look and detail of these products has gone up and down. Some amazing sets have been produced like the legendary 4558 Metroliner, and there have also been some duds such as 4560 Railway Express from 1999. One of the primary differences between the train you would purchase if you ran down to your local LEGO Store right now and many of these other sets is how they are powered. The LEGO Group standardised the Power Functions model for both Trains and Technic to reduce costs, but when did this occur? Let’s take a ride on the rails of history and find out.

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Interestingly, the very first minifigure scale trains used a system remarkably similar to Power Functions. A train engine component formed the wheels of the engine and was powered by a battery box located in the tender/coal car, the engine itself, or another nearby car connected by a wire. If that system sounds familiar, it should as it is exactly how it works today, just with much smaller components.

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In the late 1980s, LEGO designers began to mix it up. The multi-piece track which had been in use (albeit in different colors) since the beginning had a centre piece added to it. This was the 12V train system and using a special motor component mounted in the engine it could run like a model train by electrifying the center of the track. This system of electrifying the track evolved into the 9V system which was used throughout the 1990s when an entirely new set of track with metal rails was introduced. This new track was paired with a speed regulator which could raise or lower the power being sent to the engine. The advantage of this system was the relatively few components that needed to be on the actual train. Whereas today a battery box, IR receiver, and engine all have to ride the train itself, all that was needed with this system was a motor.


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Image courtesy of

The problem with this system was the amount of extra gear required and the high cost of entry. The metal track, the speed regulator and the motor that could conduct electricity through the wheels into the gears – it all added up. Because of this, trains remained a largely niche theme until the new millennium. Ultimately the switch to Power Functions was about reducing the price of entry so that the average child could have a working train, something that was not possible with the 9V system. There was one more change before Power Functions, however.


A pair of trains released in 2006 marked LEGO’s single interim attempt at a new train system outside of Power Functions. This special piece was a giant battery box intended to have a train car built around it. The two sets which it was part of struggled to build a decent train around it and the cost of producing such a piece is likely to have been astronomical.


The pair of trains released in 2010 – 7938 Passenger Train and 7939 Cargo Train were the first sets to use the Power Functions system. Just like their earliest brethren, plain plastic track is traversed by a train powered by an on-board battery box and motor. This time, an IR receiver is also included that allows the speed of the train to be controlled by the remote. This system is the best of both worlds, the convenience and control of powered track, without the need for components that prohibitively expensive. There has been a notable increase in the number of trains produced since the system was introduced, so the goal of widening the theme’s appeal appears to have been accomplished.



When I was 3 years old my dad bought home 6659 TV Camera Crew as a gift — he had no idea what he had just unleashed. Three decades and no dark age later, I am still going strong. My love of LEGO led me to a career in Civil Engineering and I am now raising three budding LEGO lovers with my lovely wife who is, bless her, a huge supporter of my brick addiction. When not writing for Brick Fanatics or fulfilling my duties as the U.S. Editor of Blocks Magazine I enjoy collecting, MOCing, exhibiting, as well as running, climbing and home improvement.

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