LEGO Trains as a theme dates back to 1966, when the first sets of railroad-guided trains were introduced. Those first trains either had no motor at all or were powered with a 4.5V motor using three C batteries installed in the locomotive itself or in a separate car. 1969 saw the arrival of the fancier 12V system, which ran the trains using powered rails added onto the track and allowed the use of remote controls like real model trains. This first era is commonly known as the "Blue Era" after the color of the rails.
In 1980, the "Blue Era" gave way to the "Gray Era". The color of the rails was not the only change that happened: the 12V system was greatly expanded, with the addition of light bricks for the trains and rail lamps as well as various remote-controlled features like decouplers, signals (which now allowed multiple trains on the same layout) and railroad crossings on top of the points which were already remote-controlled in the Blue Era. Non-powered and 4.5V trains were still offered alongside 12V during that era.
In 1992, a new 9V standard was introduced, ushering in the "9V Era". This system powered the trains using the outer rails, eliminating the need for the extra powered rails that the 12V standard used. A major downside was that it featured no remote controls outside of a speed regulator. This posed a problem to those who wished to convert from 12V to 9V: while it was easy to swap the motors in the trains themselves, there was no substitute for the various remote-controlled features of old. Meanwhile, those who stuck with 12V were left stranded when LEGO discontinued manufacturing replacement parts for 12V by the mid-1990s.
After the release of 10183 Hobby Trains in 2006, the 9V system was replaced with the RC system. Trains were now powered with a battery pack on board (like the old 4.5V system) and controlled with a infrared remote control. While the battery pack made custom builds more difficult, the new system allowed more flexibility in building tracks without worrying about short-circuiting the powered rails and could, for the first time, actually run multiple trains on the same layout independently.
The first RC system, which proved rather unpopular, was replaced in 2009 by the Power Functions system, which was already established in LEGO Technic. This system allows running up to four trains independently and can control two functions on each train; if only the motor is controlled, the number of trains can be doubled to eight.
Some LEGO Trains tropes:
- All There in the Manual: There was a trick to keep the short-lived 12V lightbricks from dying en masse when used for stationary illumination, and that was to connect two of them in series and thus run them on 6V only. However, the only source for this information was the LEGO staff.
- There's no information whatsoever about what to do when you run out of 12V traction tires (other than to convert your whole layout to 9V). The solution, namely to cut pieces out of inner tubes for racing bicycles (which is also cheaper than LEGO's original traction tires ever were), is available from users only.
- Art Shift: LEGO trains changed their looks many times, but in 2002, LEGO caught up with AFOLs at modeling and presented the Super Chief which hardly looks like a toy anymore with its SNOT front end and handrails. They did it again in 2009: The Emerald Night conceals almost all of its studs.
- Audience Shift: While there are still entry-level sets, LEGO has been targeting their cool, big train sets at AFOLs directly for almost ten years now.
- Brand X: The nameless railroad company introduced with the 9V trains in 1991. Also, Octan tank cars.
- On the other hand, Gray Era 12V trains could be fitted with stickers from all European national railroads, and 9V trains proudly wear American railroad names and liveries.
- Cool Train
- The 7740 Trans-Europ-Express, the biggest set until the launch of the 7745 High Speed Train which it outshines nevertheless. Also because the locomotive was the only LEGO vehicle with pre-installed illumination at that time.
- The Santa Fe Super Chief, sets 10020, 10022, and 10025. A train that looked like it was modeled by an AFOL. Since the locomotive was sold separately, many fans bought several ones, sometimes even enough to build at least one B unit, and run their Super Chief multi-headed. Other fans managed to build Fan Remakes in exactly the same shape but different liveries such as a California Zephyr with locomotives in the Denver & Rio Grande Western livery.
- The Hogwarts Express. Even the one with 12V wheels and without motor, rails, and tender. Even more so when modded with parts from an Emerald Night locomotive.
- The 10194 Emerald Night. The first train that's ready for Power Functions. The locomotive is LEGO's very first Pacific and easily the best-looking LEGO steamer ever made. Also, this set mostly avoids leaving any studs visible. Since it comes with only one car, many AFOLs buy two or more and use the spare locomotive parts to build their own steamers or convert their 9V Hogwarts Express locomotive to something that resembles a Castle class more closely — in fact, since the Emerald Night is sold without tracks and usually unpowered, it's quite reasonably priced by LEGO standards.
- Since we're talking about LEGO, there are countless MOCs to which this applies, too.
- Guilty Pleasure: It's already difficult to explain having a model railroad. Now try and justify your huge LEGO layout. Makes one wonder what people say who go into stores to buy three or four Emerald Nights at once ("Eh, I've got four nephews...").
- Genre Shift: Several times. In 1991, LEGO Trains quit being a model railroad technically (which it had been since 1980 when points and signals could be remote-controlled) when switching to simpler technology. Eleven years later, LEGO Trains suddenly turned into a model railroad style-wise and copied some superior modeling methods developed by AFOLs.
- Just Train Wrong:
- The Gray Era trains all came with stickers of all major European railroads, no matter what they were based on. While one could be careful to only stick DB stickers on the 7740 Trans-Europ-Express or SNCF stickers on the 7745 High Speed Train (based on the TGV Sud-Est), it's doubtful most kids cared back in the day.
- Of all train destination stickers for 7740, only BaselHamburg and maybe WienZürich (in case the train would run via Munich) would have been realistic.
- There have never been any mail (7820, 7819) or sleeping cars (7815) in Trans-Europ-Express consists, let alone in the red/yellow livery.
- A restaurant in one of the end cars of a TGV (7745)? What the? On the other hand, having two power cars like in Real Life would have made the train too long and too expensive.
- The Metroliner combines an Amtrak livery with side buffers. The BNSF freight locomotive has them, the TTX container car has them, and the Super Chief lacks buffers on the locomotive's cab end only. In Real Life, American railroads have no side buffers, however. Then again, LEGO also put side buffers between the locomotive and the tender in the 7750 set.
- The cheapest Hogwarts Express comes without a tender. Admittedly, Pottermore says that the Express was heavily enchanted before it was approved for Hogwarts use, so it might not even ''need'' coal to run.