Wednesday, 4 April 2012


Honestly, what was I thinking ? Infrared remote control requires line of sight in order to operate the device - it won't work through walls. So if you place the device that you wish to control, for instance a LEGO train, in a place without line of sight to the controller, say in a long, enclosed section of railway tunnel, then it won't work. Duh.

Above (as with all the pictures, click to enlarge) you can see where I'd got to with my LEGO city layout the last time I blogged about it; eventually the whole loop of track will be fully enclosed, and the plan is to ultimately run an extended 5-car version of Set 7938 Passenger Train on this loop. Problem is that the standard, unmodified train is operated by infrared remote control, so for the majority of its progress around the enclosed loop of track I won't be able to control it. Whoops.... So what to do ? Well it's thankfully not an insurmountable problem, but it has once again necessitated an unplanned excursion into my wallet for what I think is the optimal solution.

For those of you of a more tender age, it's probably time for a quick history lesson. Since the appearance of LEGO trains in the mid-nineteen sixties, the company has utilised a variety of methods for making trains move by themselves. Initially it was 4.5V motors powered by huge on-board battery boxes. Then in the late sixties LEGO introduced a system of 12V motors running on electrified track; this system gave rise to some of the most iconic and revered trains that LEGO have ever produced, not least Set 7740 Inter-City Passenger Train (below).

This 12V system endured for two decades, eventually being phased out in the early nineties when LEGO transitioned to a system of 9V motors running on a different, moulded type of electrified track. This 'era' ran until 2006, and the introduction of the Remote Controlled, or RC, system which reverted to non-electrified track and motors once again powered by on-board battery boxes. Importantly, however, as the name suggests trains could for the first time be controlled remotely without the need for a physical connection between train and operator. The RC system was short-lived, however, giving way to the Power Functions-based system a few years later. This PF system, which is what LEGO currently sells, also employs non-electrified track, motors powered by on-board battery boxes and infra-red remote control which requires line of sight in order to control the train. Bringing things back to the present, it's this PF system which is used by the train I plan to use in my underground track loop, and hence my little problem....

So the solution ? 9V. Despite having been officially phased out by the LEGO company a while ago now, 9V is still probably the standard for AFOL builders of public LEGO train displays. The track is no longer produced by LEGO and is relatively expensive on the secondary market, as are the motors, but critically for me, train control is via a speed regulator attached to a section of track by wires so there's no need for line of sight, nor is there the potential for batteries to run out with the train stuck deep in a section of tunnel.... Talking of public train displays, and the observation that most seem to employ 9V, there's also another possible advantage - when I finally complete my layout and my attention shifts to the question of public display, if I use 9V track then it raises the possibility of linking my layout with that of someone else to produce a much larger collaborative build.

Anyway, once I'd sourced (and paid for....) the required quantity of dark bley 9V track, it took no time at all to replace the existing track in my layout with the 9V alternative and wire it up to a speed regulator. You can see where I've currently got to with my layout in the pictures below (click to enlarge); use of a wired system is certainly messier and less elegant, but it"s a compromise I'm willing to make in this case.

The other thing I needed to do, of course, was to convert my train from PF to 9V. Having previously had few dealings with 9V beyond buying a couple of old 9V sets for my collection, I approached this task with some trepidation. I needn't have worried, however - it was incredibly simple. From the outside, the standard 9V motor seems to be pretty much identical to the PF motor included with Set 7938 Passenger Train, so it was literally a matter of disconnecting the PF motor from the battery, removing it from the train chassis, and attaching the 9V motor in its place. I could have stripped out the PF remote receiver and battery box at this point given they were no longer needed to make the train move, but decided instead to retain the PF components to power and control the front and rear lights of the train instead.

You can see the train running on the newly laid 9V track loop in the (decidedly ropey) video clip below, complete with PF-powered front and rear lights. These are turned off and then back on again about halfway through the clip using the remote control.


So another small step forwards, then - ever onwards !

<-- LEGO City Layout : previous blog entry                  LEGO City Layout : next blog entry -->


  1. Thank you for the train history lesson. I've never owned one, but will certainly keep it in mind if I ever get around to planning a town/city layout that incorporates track.

  2. Branko Dijkstra5/4/12

    Funny, I would have put up a few small mirrors at the corners of the tunnels and one on one side. The power of the infrared leds should be plenty for such a solution.
    It wouldn't even have occured to me to find powered train track :)

  3. The 9V / PF debate aside - I honestly wonder sometimes about TLG's strategy with us train enthusiasts. I haven't seen a single leak for a new train this year (aside from the hokey Monster Fighters one), but in 2011 at one time you had 5 at one time - the Maersk, Emerald Night, Cargo trains (yellow then red) and then the aforementioned Passenger Train. The history lesson you have given and your own layout shows the downsides of PF. Accommodating the battery box is the most difficult task of all. I would have preferred a similar hybrid system - PF LED light features with the 9V engine (and a smaller battery box).

  4. Anonymous6/4/12

    are all those boxes unopened?

  5. ^ Some of the boxes are sealed and some aren't.

    Interesting - I never thought of putting mirrors in the tunnels to distribute the IR signal, although to be honest I doubt it would have done the trick - even when shining the remote down the short section of completed tunnel with the train directly ahead it was hit and miss whether the train would respond. Nice idea, though !

    Regarding TLG's train strategy, I agree it's hard to fathom. The appearance of the Red Cargo Train last year with so many trains already on the market was particularly unexpected, not least because the profitability of the trains is apparently so marginal. That having been said, I'm delighted that we've been blessed with so much train-related product over the past couple of years. Let's just hope that we get a fitting replacement for Emerald Night...

  6. So I take it you have a load of PF track with no use?

    Also, Huw seems to have disabled your images :-)

  7. ^ I'll still be using PF track for the upper level.

    Regarding images, the server hosting Brickset has started blocking embedded images all of a sudden; Huw's looking into it, and assures me it wasn't his decision !

  8. Branko Dijkstra10/4/12

    I'm somehow quite positive that TLG's train strategy is based mostly on the enthousiasm of some of it's employees.
    However me and my kids jump on just about any train that comes out. It would just be great if they had some cheaper train sets (just wagons or unpowered trains or something).

  9. Richard Selby10/4/12

    My idea - TLG should have a train available for some of the play themes, so a Ninjago train, a Friends train, a dino train. I can't really see a SW train or Architecture train working, but you get the idea. More ways into trains, and more trains for the train fans.

  10. So with PF still on the train, does this mean your train can operate on both type of tracks? You need a "gauge" conversion station to transfer from one system to another... lol

  11. "So with PF still on the train, does this mean your train can operate on both type of tracks? "

    Nope - I chopped the PF motor and replaced it with a 9V one; the PF receiver and rechargeable battery box are still inside, however, which means I can remotely operate the front and rear lights, but without the PF motor the train would grind to a halt on non-electrified track.

    1. Couldn't you put a 9V motor on one locomotive and a PF on the other?