Shunting puzzle: designing a small yard
Benjamin | TrackDrawer.com · published 3 November 2026
A shunting puzzle is a small yard with a fixed task: make up a train from the wagons waiting there, in a given order, in as few moves as possible. You need very little for it: a headshunt, two turnouts and three sidings. The game lies in the lengths of those tracks, which is why you count them in wagons rather than centimetres.
Why a few tracks become a puzzle
In a large yard there is always room somewhere. In a small one there is not, and that is exactly the point. Each siding holds only a limited number of wagons, and the locomotive can only take a few wagons at a time onto the headshunt. So you have to think ahead: which wagon do you move first, where do you park it for now, and how does the wagon at the back end up at the front of your train?
The best-known form comes from British railway modelling, where it is called the Inglenook. The arrangement is always the same:
- A headshunt for the locomotive plus three wagons. That is the brake on the game: you cannot pull out more in one go.
- Three sidings holding five, three and three wagons.
- Eight wagons spread over those sidings. The task: pick out five of them in a given order and assemble them as a train on the long siding.
You can draw a task with numbered cards, for example. That way every round is different on the same bit of track. Larger variants add a run-round loop so the locomotive can change ends; that allows more tasks, but also needs more turnouts and length.
How much room do you need?
The length follows from the wagons and the turnouts. If you lay the headshunt and the long siding in one straight line, with a left-hand and a right-hand turnout one after the other, the puzzle is as long as the headshunt (four wagon lengths), the straight length of two turnouts and the long siding (five wagon lengths). The short sidings on the left and right sit alongside through a matching curve, at the track spacing. The width is then twice that spacing plus the track bed.
The table uses the standard coach TrackDrawer works with for each scale: a long bogie vehicle, 250 mm in H0, 136 mm in N and 99 mm in Z. The locomotive counts as one wagon.
| System | Wagons (9 lengths) | Two turnouts | Puzzle length | Track width |
|---|---|---|---|---|
| Märklin C track | 2250 mm | 376.6 mm | 2.63 m | 195 mm |
| Kato Unitrack H0 | 2250 mm | 492 mm | 2.74 m | 190 mm |
| Piko A track | 2250 mm | 478.1 mm | 2.73 m | 167 mm |
| Minitrix (N) | 1224 mm | 208.4 mm | 1.43 m | 83 mm |
| Kato Unitrack N | 1224 mm | 372 mm | 1.60 m | 91 mm |
| Märklin Z | 891 mm | 220 mm | 1.11 m | 66 mm |
The wagons take by far the largest share. So it pays to measure your own: with short four-wheel goods wagons only that part shrinks, while the turnouts stay the same length. Work it out like this: length = 9 x your wagon length + 2 x the straight length of your turnout. Add the buffer stop and a few centimetres of clearance to the sidings, and keep a 5 cm margin to the edge of the baseboard.
The width is small. Even with margins a shunting puzzle stays under 30 cm in H0 and under 20 cm in N. It fits on a shelf, as a layout of its own or at the end of a shuttle line.
What the Auto-designer puts in
The Auto-designer places yards inside a loop: two turnouts of the same hand one after the other, with two sidings side by side, as long as the baseboard allows. It calls this "Yard on" followed by the radius. A few runs with a typical drawer of track and a 5 cm margin:
| System and baseboard | Plain loop | With yard |
|---|---|---|
| Märklin C track, 180 x 90 cm | Oval R1: 22 pieces, 4.11 m | Yard on R1, plus siding: 38 pieces, 5.92 m |
| Märklin C track, 240 x 120 cm | Oval R3: 32 pieces, 5.69 m | Yard on R3: 40 pieces, 7.31 m |
| Minitrix, 120 x 60 cm | Oval R2: 16 pieces, 2.68 m | Yard on R2: 29 pieces, 3.52 m |
That is a yard beside a continuous run, not a measured puzzle: the sidings are as long as the baseboard allows, not matched to a number of wagons. If you want a true puzzle with fixed lengths, draw it yourself in the editor. More on sidings inside a loop is in siding and buffer stop; what else fits on a small H0 baseboard is covered in an H0 layout on 180 x 90 cm.
Tips for a puzzle that plays well
- Get the lengths exact. A siding for three wagons has to hold three wagons, not four. Put a mark on the baseboard or let the buffer stop do the work. If the siding is too long, the puzzle disappears.
- Keep the headshunt short. The headshunt decides how many wagons you take in one move. A headshunt for the locomotive plus three wagons makes the game; a longer one makes it easy.
- Straight where you couple. On a straight the wagons stand in line and the couplings engage better. An uncoupling track where you drop wagons saves poking at them with your fingers.
- No S-bend in the headshunt. Two opposite curves with no straight between them can lock buffers when pushing. TrackDrawer gives a tip when there is less straight between two opposite curves than the length of a standard coach.
- Run slowly. A locomotive that crawls smoothly matters more than which turnout you choose. Real shunting happens at walking pace too.
- At the front. Put the puzzle where your hand can reach it. You couple, uncouple and now and then set a wagon back on the rails.
Frequently asked questions
Can a shunting puzzle sit in a terminus?
Yes, a small terminus with a goods siding is effectively a shunting puzzle: the wagons have to go to the right track in the right order. A run-round loop makes it easier; without one it becomes a puzzle.
How many turnouts do I need?
Two for three sidings. A left-hand and a right-hand turnout put the short sidings on either side of the long one; two turnouts of the same hand put both on one side, which sometimes fits better in a corner or against a wall.
Try it yourself
Draw your puzzle in the app, add your own wagons to the plan and check that each siding holds exactly the number of wagons you want.
