[2024-03-14: I’ve since written a longer and nerdier post on this topic, which calls into question the decisions I made here.]
For me the most satisfying LEGO models manage to capture the essence of the original while staying within the confines of the regular grid and the standard range of available pieces. There are always compromises to be made, and balancing those compromises is an art, whether we’re recreating towers, trees or … trains.
I’ve only recently rekindled my childhood interest in LEGO, and LEGO railways in particular. LEGO trains and track today are a world away from those of my 1970s childhood, when the trains had little red studded wheels, and the fragile track was built from blue rails joined by widely separated white ‘sleeper’ plates!
Today’s track is much more robust, and bears a far closer resemblance to the real thing:
To make our track look a little more realistic still, we could add suitably coloured tiles to cover the studs on all the sleepers, and then fill in and around the sleepers with plates matching the track to give an impression of ballast – the stones that hold a real railway in place:
But why doesn’t that look quite right? The main reason is probably that the sleepers in normal LEGO railway track are way out of proportion to the track gauge (and in themselves) in comparison to the real thing – in most cases anyway.
Let’s get real
For a modern standard-gauge railway, the track gauge for straight track is 1435 mm, while sleepers come in a variety of sizes (and indeed shapes – few are strictly rectangular nowadays). Here are some concrete sleeper dimensions gleaned from a fairly quick search:
| Country | Width (mm) | Length (mm) | Source |
|---|---|---|---|
| Australia (NSW) | 220–255 | 2390–2500 | Specification SPC 232 (PDF) (original) |
| Canada/US | 254–280 | 2500–2600 | Vossloh brochure (PDF) (original) |
| Germany | 298–320* | 2400–2600 | RAIL.ONE brochure (PDF) (original) |
| Spain | 300 | 2600 | RAIL.ONE brochure (PDF) (original) |
| UK (GB) | 285 | 2420–2500 | Turkington brochure (PDF) (original) |
I haven’t included heights in the table, as all but the tops of sleepers are usually hidden by the ballast. That means that the widest parts of most concrete sleepers are hidden too, so most of the widths in the table are greater than the visible widths of the sleepers. The Turkington brochure referred to in the table gives the base width of the ‘G44’ and ‘5F40’ sleepers that they manufacture as 285 mm, but they also indicate that the width at the top of the sleepers is 200 mm.
Working to scale
Using modern LEGO track as a starting point, our track gauge is fixed at approximately 5 studs. (Because LEGO rails work differently from real rails, a centre-to-centre gauge makes sense.) This leads to a nominal scale of 1 stud to 287 mm – about 1:36. [2024-03-11: The L-gauge standard for track geometry contradicts this, and I’m not sure that LEGO rails do work that differently now. I have another post coming out shortly, which I hope will clarify matters.]
If real sleepers are, let’s say, 200–250 mm wide above the ballast, and we want to have proportionally scaled sleepers, they will need to be 0.7–0.9 studs wide. Even at 320 mm wide, they would still be only 1.1 studs wide. Since fractional studs are hard to come by, a sleeper width of 1 stud makes much more sense than the 2 studs of the LEGO track pieces, and this is what most AFOLs/AFOBs (adult fans of LEGO/bricks) seem to use (if they can afford to). It’s common to halve the sleeper spacing too, so that the sleeper/space ratio remains the same:
Alternatively, it would be possible to keep LEGO’s 4-stud centre-to-centre sleeper spacing and merely change the width of the sleepers, but the resulting 1:3 sleeper/space ratio makes the track look, to me, more like the kind of track found on some narrow-gauge railways. It might work well for a 1 stud to 200 mm, or 1:25, scale rendition of such a railway. (But we would need a lot of bricks to work at that scale!)
The twist
Concrete sleepers on full-size railways are usually spaced with their centres 600 mm apart. (Wooden sleepers, less commonly seen these days, are typically a little closer together.) Sticking with the scale derived from the track gauge, that would require LEGO sleepers to be spaced 2.1 studs from centre to centre. So perhaps the widely used L-gauge standard (with the 1:1 ratio) is indeed the best choice.
But wait a moment! The only reason this 1:1 ratio appears is because we rounded 0.7–0.9 studs up to 1 stud, and rounded 2.1 studs down to 2 studs. If, as is often the case, the visible tops of concrete sleepers are around 200 mm wide, that is a third of the usual centre-to-centre sleeper spacing (just as 0.7 is a third of 2.1!).
To be concrete (if you’ll pardon the intentional pun), suppose we are modelling sleepers that are 200 mm wide (on top) with 600 mm spacing. We could represent the sleeper width as 1 stud (43% over scale) and the sleeper spacing as 2 studs (5% under scale).
Or … we could represent the sleeper width as 1 stud and the sleeper spacing as 3 studs (both 43% over scale, but perfectly in proportion with each other):
I said at the start that LEGO modelling is the art of compromise, and I personally think this is an aesthetically preferable compromise to the one usually adopted. Most of my photographs of concrete-sleepered real railways show a clear sleeper-to-gap ratio of close to 1:2, and the difference between this and a modelled 1:1 ratio is far more easily detectable by eye than the difference between the 0.7:5 ratio of sleeper width to track gauge and a modelled ratio of 1:5.
And I suspect the sleeper-to-gap ratio is far more noticeable at a glance than any discrepancy between the total number of sleepers and the length of a train. What do you think?
Incidentally, the 8-stud sleeper length is about 4–12% under scale for 2400–2600 mm sleepers. But 10-stud sleepers would be 10–20% over scale, so I doubt there is much to be gained from tweaking this. And though 10-stud sleepers would push the sleeper length-to-width ratio closer to the prototypical 12:1 or 13:1, it would also introduce greater errors in the ratio between the sleeper length and the track gauge. Aargh!
The price of bricks these days
Lego isn’t cheap (though much cheaper alternatives are available, and I’ve been very pleased with the Blue Brixx models I’ve built). According to Bricklink Studio, in which I modelled all the examples, six new LEGO straight tracks (96 studs long in total) would currently cost about £6.33. Adding ornamental sleepers (new parts) in any of the above styles will put the cost up to 2 or 3 times that. The currently favoured ‘standard’ is the most expensive, at £20.08, with the 2:2 ratio costing little less. My preferred 1:2 ratio is £17.32, and the narrow-gauge-aesthetic 1:3 ratio comes in at £16.10. (Those prices may be balanced out by further levels of detail, though: extra ballast in the wider gaps will certainly cost more.)
Incidentally, the light grey sleepers depicted are eye-wateringly expensive. I used Studio to give me the prices for black sleepers instead, as soon as I realised that I’d created a (virtual) rich person’s indulgence!