Digital Trainspotting

I know that computers and digital electronics have almost completely taken over our world, but it was still an eye-opening experience to see just how much they have infiltrated one of my peripheral interests: model railways.

Many years ago, when space and time permitted, I indulged physically in the world of railway modelling. It's almost mandatory for the real anoraks and ex-trainspotters who are generally into railways (the full-size ones). Even if it's only by joining a local society and/or visiting model railway shows. Though my early experience as an active modeller, some 30+ years ago, came to an end through a combination of moving house and Clive Sinclair (I bought a ZX80 and never had time for any other hobbies after that).

At the time, in conjunction with an interest in electronics, I was attempting to replicate a section of the East Coast Main Line complete with fully operational signaling, block working, switching, track circuitry, etc.; an area of the real railway environment that has always fascinated me. But, though the full size railways were pretty much fully digitized and electrically powered even back then, the ability to replicate it in model form was severally hampered by the lack of suitable, easily-available hardware.

Yet a trip over the holiday weekend to the model railway show at York (one of the primary shows of the year - and somewhere that, years ago, was an annual pilgrimage) revealed just how much has changed; and what it actually possible now for even the most ham-fisted railway geeks amongst us. Especially those with a parallel interest in computers.

Most of the electrical control logic for my unfinished project was based on banks of miniature 9 volt relays, miles of wiring, a few integrated logic chips containing AND/OR gates, and big hot transformers to supply all the current it required. All of which could be easily hidden in a cupboard. But the visible items, in particular signals at 1:148 scale (2mm to the foot / N-gauge) required working lamps of around 1.5 mm diameter. In those pre-"cheap and hugely varied range of LED" days, the smallest was a 3 mm diameter "grain of wheat" bulb. Building a working 4-aspect colour light signal was a task well beyond my capabilities, and nothing even close was available commercially. Yet, now, you can buy ready-made 2mm scale colour light signals in a range of styles. Even though, it seems, 3-aspect is the maximum; but I also found cheap 1.5 mm diameter LEDs so it would be reasonably simple to build 4-aspect signals and other more esoteric combinations such as junction signals.

Meantime, the availability of reliable 2mm scale locomotives and chassis was a real problem 30 years ago. A few German chassis were available at huge cost if you fancied building the superstructure yourself, or adapting a kit. But even with these high-quality items, the principle of powering them with a variable DC voltage meant realistic speed and slow running was not guaranteed. Now the trend is digital command through a constant 15 volt AC signal applied to miniature decoders in each loco. From what I saw, accurate and reliable running seems easily achievable even in 2mm scale locos measuring less than three inches in length.

The digital command control systems allow control of anything that is electrically powered. Internal lighting for coaches and buildings, loco head and tail lights (that change automatically), signals, turnouts, road crossing barriers and gates (and warning lights), even the flickering glow from the firebox of steam locomotives. Plus the use of high-intensity white LEDs to replicate arc welding in a workshop that seems to be almost mandatory on many layouts now. And the hand-held controller is, of course, wireless these days - so you can wander about while driving.

And one relatively new feature, driven by the command control systems, is digital sound. On many layouts, the locos sounded just like the real thing, with the engine note changing to match speed, the sound of air brakes, and a realistic tickover when stationary. On one sales stand I even discovered that you can program the sound chips with the actual type of the loco, and it emits sounds recorded from the real thing. Amazing.

But it doesn't stop there. In the "olden days" we used to build track plan panels with embedded lights, just like the real thing, and populate these with the switches for turnouts and isolated sections that allow multiple locos to be used. With digital command control, isolated sections are no longer required and combinations of turnout settings can easily be set up in one action. And when you add in a computer, you can easily introduce additional logic features such as block working and proper locking of signals and turnouts.

In fact, several of the layouts were completely controlled by a laptop computer that displays a clickable live track plan that controls everything. In some cases, automatically driving all the trains as well. Though I guess this just matches my continued surprise when I go to a social event where there's a disco and discover that there are no record decks or even CD players any more - the DJ just runs the whole thing from a laptop.

I'm not sure we aren't heading for a time when railway modelling becomes a spectator hobby. OK, you still need to build it first, but there were some complete layouts for sale at the show. Perhaps in the future the younger generation will just order their model railway online, set it going in the spare bedroom, and spend the rest of the evening tweeting and facebooking their friends with status updates about the trains they've seen going past.

Maybe trainspotting is about to see a whole new lease of life...