In 2002 the LEGO company released a remarkable new train set as part of their Explore line of building brick toys. This train set is compatible with the DUPLO size bricks and the earlier DUPLO train tracks, but it also includes an extraordinary new code brick system. The code bricks allow the train to be programmed by placing code bricks between track rails. As the train runs across a code brick, sensors on the underside of the train are pressed by the code brick and the train responds by stopping, reversing, speeding up, and making a variety of sounds appropriate to the situation. The Intelli-Train also employs sensors to determine which of the two engineers was driving the train so it can respond differently for each of them. The Intelli-Train set is further expandable with a variety of add on sets including a intelligent rail-car that can react as a passenger car or a cargo car depending on what pieces are set on top of it. The intelligent car communicates back to the engine as either cargo or passengers are loaded or unloaded. If the train was stopped on the appropriate cargo or passenger station code bricks, then the engine responds to what's happening on the intelligent car with the appropriate sounds.

The LEGO Intelli-Train and Related Sets

10052 Intelligent Locomotive Set

3335 Intelli-Train Starter Set

3326 Intelli-Train Cargo Set

3327 Intelli-Train Station Set

3334 Intelli-Train Tunnel Set

3325 Intelli-Train Gift Set

9125 Intelligent Train Set

Also see the Intelli-Train pages on these great LEGO fan sites:
Peeron.com - includes part inventories for most of the sets and a manual for the Intelli-Train Gift set 3325
Lugnet.com - pictures, ratings, and set information
BrickLink.com - you can buy parts and sets from many independent venders here

Here's a page of some of my Duplo Track Layouts
The tracks follow different plans and layouts than other LEGO train sets. The tracks have different curvatures than other sets and the points are a Y shape rather than a usual parallel points.

LEGO continues to release new DUPLO train sets. Unfortunately, the LEGO company appears to have discontinued the Intelli-Train line, although some of the expansion sets have been available until recently and many still show up on eBay and BrickLink. One possible explanation for the set's termination was the tendency of the engine to remain running even when it was removed from the tracks. With the fairly powerful motor, it was somewhat common to see little fingers pinched by the wheels as children would invariably poke about the underside of the train while it ran. It's also possible that the higher production costs of the train kept it's retail prices beyond what the average consumer was willing to pay for a small child's toy.

The design of the Intelli-Train system relies on the engine to produce the sounds for the rail-car, so any expansions to the system require the sounds and behaviours to be built into the engine, even before these expansion sets become available. It's quite possible that LEGO may have included behaviours for new expansion sets that never made their way to market. Because these behaviours are already built into the Intelli-Train engine, it is also possible to recreate the unpublished code bricks and add new features to the Intelli-Train.

In researching the DUPLO Intelli-Train, I was unable to find a comprehensive online guide to the features of the system and the functions of each of the code bricks. I set about to build this site to record the research and to let the LEGO community know about the discovery of two unpublished code bricks for the Intelli-Train.

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Code Brick Actions and Sounds