Home LEGO creations ministeck mosaics Contact

About Rail Tracks

February 2008

(Pictures of my creations can also be found in my BrickShelf folder)

1. The idea

LegoLand Miniland large scaled trainsTo all those who ever paid a visit to one of the LegoLand parks: where you as amazed as I was when you first laid eyes on one of those large scaled trains?
Those are really magnificent models; every Lego train fanatic would love to have one of these driving through his backyard. Unfortunately these trains are only from Lego on the outside: the mechanism that drives these trains isn't, nor are the rails. Although Christian Krützfeldt assured me that those tracks were moulded at TLC too, I don't consider them real Lego-parts.
Wouldn't it be wonderful if TLC started a new theme with larger scaled trains? Basic sets wouldn't have to be motorized, because with the new Power Function system they already have everything that is required to get them running.
However, there is one problem: the track geometry. I have seen a few train fanatics who have already tried to build a larger scaled train: Christian Krützfeldt showed his model at the 75th anniversary of Lego in Billund, but I also found some BrickShelf users, e.g. BrickBaron, Reinard Van Loo, and Vincent Veneman with beautiful large scale train models. These creators all suffer the same problem: their trains can't run on standard Lego railtracks. Best case scenario: if 4.5V straight rails are used with a different trackwidth, the trains can run straightforward, but never through curves.

Since metallic parts have dissappeared (from 9V to RC-rails), it would become easier for TLC to create different track geometries: they've already admitted that they would consider doing it. But what type of track should that be? Within the AFOL-community there have been lots of discussions regarding this matter. I'd like to do my share, right here.

Märklin has three different train-scales:

  • Z gauge: with a scale of 1:220
  • HO: with a scale of 1:87
  • MAXI / 1 gauge: with a scale of 1:32

What if Lego came up with a new system of railtracks (we already know that the L-gauge will not disappear!) that would allow three types of trains all running on the same tracks? Here's my solution:

2. New parts

First of all I studied the way parts are created for LDraw to be used in e.g. MLCad. Because RC-rails are very difficult parts to create - especially the curved one with a different radius - I will be using 4.5V rails in a representational way.
I started modifying the old straight 4.5V rails, because the new RC-rails are smooth opposed to the ribbed 4.5V rails. Then I reproduced the inner 4.5V curve: this one has a radius of 37.5 studs. Starting from this curve it was rather easy to create 5 more smooth curves with radii of 42.5, 45.5, 50.5, 53.5 and 58.5 studs respectively. From now on, I'll refer to them as C1-2 (40 studs radius), C3-4 (48 studs radius) and C5-6 (56 studs radius) respectively.

New curved rails

The straight track (partnumber 53401) and C1-2 already exist (partnumber 53400), one more curve is required (I suggest it's made in a different colour, to be easily distinguished from C1-2). But what to choose: should it be C3-4 or C5-6?
To make my point I illustrated my story with a prototype (unfortunately unfinished models, by lack of bricks/time) of a locomotive, based on the Belgian electric locomotive from the 12-series.

3. Curve 3-4

Creating another curve will open up lots of new possibilities:

Small train

For a train with the new RC train wheels:

  • distance between axles: 7 studs
  • distance between bogies: 22 studs
  • total width: 7 studs
  • total length: 45 studs

(Image on the right: yes, I cheated. I don't have the new RC train wheels yet.)

Small train
Medium train

For a train with bigger wheels, e.g. wheels the size of a technic gear 36 tooth:

  • distance between axles: 11 studs
  • distance between bogies: 34 studs
  • total width: 11 studs
  • total length: 70 studs

I also noticed that these wheels have approximately the same size as the custom BBB-wheels.
Roborider-wheels have the same size too, but they don't have an axlehole (and unfortunately there's no LDraw-file available for this element).

Medium train
Large train

For a train with the really big motorcycle wheels:

  • distance between axles: 18 studs
  • distance between bogies: 58 studs
  • total width: 18 studs
  • total length: 119 studs
Large train

If we take a closer look at the bogies only:

Small train bogie Medium train bogie Large train bogie

Distance between axles is 7 studs; this won't cause any problems at all.
This train can run on tracks 1-2 or tracks 3-4. However, it's not possible to have two similar trains running on both tracks: they will collide in the curves.

Distance between axles is 11 studs. Wagons of existing Lego trains usually have 10 studs distance between axles. Maybe this one needs to be redesigned (testing can only be done once new tracks are available).
This train can run on tracks 1-3 or tracks 2-4.

Distance between axles is 18 studs. To make this bogie go smoothly through curves I designed an articulated bogie (with 4-wheel drive!).
This train runs on the two outer tracks 1-4.
Important remark:
These wheels run smoothly on the old 4.5V rails, but not on the 9V rails. The upper section of the 9V rails is unfortunately slightly wider (7 LDU) than the 4.5V rails (4 LDU).

4. Curve 5-6

In 2007 TLC already released a new rail crossing (set 7996). Both tracks are 16 studs seperated from each other. Therefore it is more likely that TLC will release a new curve with 56 studs radius (curve 5-6), to be more compatible.

Small train

For a train with the new RC train wheels:

In this case it is possible to have two similar trains running on both tracks at the same time. They won't collide in the curves.

Small train
Medium train

For a train with bigger wheels, e.g. wheels the size of a technic gear 36 tooth:

I slightly redesigned the bogie to make it possible to mount the wheels inside out, fitting them on the standard tracks. The train now runs on the outside of tracks 1-2 or tracks 5-6. However, because of the size of this train it isn't possible to have two trains running on both tracks at the same time.
This is not an ideal solution because wheels tend to come loose when the train goes through a curve at higher speed..., unless we use threaded axles (3737c01) and axle nuts (4698) to keep the wheels in place.
If TLC designs the new wheel right (symmetrical), we won't even notice it when they're mounted inside out!

Medium train
Large train

For a train with the really big motorcycle wheels:

The train now runs on tracks 2-5. Distance between tracks 1-4 and tracks 2-5 is not equal, but the train fits on the tracks without any modification: it now runs on the inner grooves of the big motorcycle wheels!!

Large train

5. What do we need?

  • Curve C3-4 (or C5-6)
  • New Lego train wheels of a similar size of BBB-wheels
  • And - if the upper section of the RC rails is more than 4LDU wide - adapted motorcycle wheels

If TLC decides to go back to the old 4.5V rails (like I did in my representation), then every train fanatic would have the possibility to only use those tracks required for his/her personal layout (e.g. only tracks 1-3 or 2-5, depending on what type of train you want to run on your tracks).

6. And there's more... much more

I don't really like it if TLC releases new parts that serve only one purpose (e.g. partnumber 2999), it's always a big R&D-cost with low usability. I want them to create a new curve, but I want it to serve another purpose, too. I was thinking of an expansion of the Lego-Racers theme:

Have you ever bought set 8364? I never really liked those track-sections: apart from the fact that they were too juniorized, track-expansion was very difficult. As you all know, TLC is working on a new system for the new PF-trains that would allow batteries to be recharged in such a way that they don't have to be removed from the train model. If this new system would be similar to the one from set 8364, then we only need new wheels for the rechargeable electric motor to make the racing vehicles fit on the traintracks. In this case I was thinking of a wheel similar to the small train wheel, but with a rubber band to avoid skidding (and maybe slightly larger?).

With a new curve, it would become possible to build custom slot car racetracks. Since train tracks are widely available, track-expansion would become much easier.
These racetracks could look like this: (I had to improvise a bit, because there's no LDraw-file available for this part).

Slot car racetrack 1

With C3-4 it's very easy to build an 8-track: 20 curved tracks (x2) and 52 straight tracks. Each racer has one inside and one outside curve during each lap.

Slot car racetrack 2

With C5-6 the 8-track looks more straightforward: standard train track crossings can be used. 4 train track crossings, 24 curved tracks (x2) and 16 straight tracks. Again a fair race: one inside and one outside curve during each lap.

Slot car racetrack 3

With the new rail crossing, it becomes possible to build a very small oval track that gives each racer one inside and one outside curve during each lap. 16 curved tracks (x2), 18 straight tracks and one new rail crossing. Too bad this new rail crossing only has 2 point levers instead of 4...

7. Epilogue

A few years ago I already had this idea lingering on my mind. With the introduction of the RC-rails and the numerous possibilities of the new PF-elements, I thought the time was right to finally put it on my webpage.
Now it's up to you SNOT-builders and train-fanatics to create a body that fits on those train-base prototypes (the small and medium model may be a little tricky because of the odd width). Let's hope TLC get's convinced to create the new elements I described... I'll leave it up to them to choose between C3-4 and C5-6 (both have pro's and con's...), unless you come up with solid arguments to help them make this critical decision...

The rendered images are created with MLCad and rendered with POV-Ray.