Left, right and symmetrical turnouts explained
Benjamin | TrackDrawer.com · published 5 November 2026
A left-hand turnout branches off to the left and a right-hand turnout to the right, seen from the toe of the turnout: the end with the moving switch blades. That hand does not change when you turn the piece around, so every spot in your plan needs the right one. A symmetrical turnout (Y turnout) has no straight road at all: it splits into two equal curves, one to the left and one to the right.
Left or right: how to look
Imagine standing on the single track and looking over the blades towards the two exits. If the diverging road runs off to the left, it is a left-hand turnout; if it runs to the right, a right-hand one. Manufacturers give each its own number. In Märklin C track, 24611 is the left and 24612 the right standard turnout; in Piko A track they are 55220 and 55221.
Turn a left-hand turnout half a turn on the baseboard and the toe points the other way. Stand at the toe again and it still branches off to the left. A turnout with moulded roadbed cannot be laid upside down either. A left-hand turnout never becomes a right-hand one.
Which hand you need follows from what you are building:
- Passing loop: one left-hand and one right-hand turnout, toes pointing outwards. The full layout of the loop is covered in the passing loop.
- Crossover between two parallel tracks: two turnouts of the same hand, with the diverging roads facing each other.
- Siding: one turnout, with the hand of the side where the siding should go.
Why the diverging road plus a counter curve lands exactly at the spacing of the neighbouring track is explained under track spacing.
Angle, radius and length
Apart from the hand, turnouts differ in three dimensions. The turnout angle is the angle between the straight and the diverging track at the end of the turnout. The diverging radius is the curve the diverging road follows. The length is that of the straight road through the turnout. A small angle with a large radius makes a slim turnout: trains run through more smoothly, but the turnout is longer and the second track leaves the first one later.
Many systems offer slimmer turnouts next to the tightest one. From our catalogue, each time angle, diverging radius and length:
| System | Tightest turnout | Slimmest turnout |
|---|---|---|
| Märklin C track | 24611/24612: 24.3°, 437.5 mm, 188.3 mm | 24711/24712: 12.1°, 1114.6 mm, 236.1 mm |
| Märklin K track | 2262/2263: 22.5°, 424.6 mm, 168.9 mm | 22715/22716: 14°26', 902.4 mm, 225 mm |
| Roco Line | 42442/42443: 15°, 873.5 mm, 230 mm | 42488/42491: 10°, 1946 mm, 345 mm |
| Kato Unitrack H0 | 2-840/2-841: 22.5°, 490 mm, 246 mm | 2-862/2-863: 10°, 867 mm, 492 mm |
| Hornby | R8072/R8073: 22.5°, 438 mm, 168 mm | R8077/R8078: 11.25°, 852 mm, 245 mm |
| Tillig Elite | EW2: 15°, 484 mm, 178 mm | EW6: 6.34°, 2200 mm, 388 mm |
| Minitrix | 14951/14953: 24°, 194.6 mm, 104.2 mm | 14954/14939: 15°, 362.6 mm, 112.6 mm |
| Kato Unitrack N | 20-220/20-221: 15°, 481 mm, 186 mm | 20-202/20-203: 15°, 718 mm, 186 mm |
| Tillig TT | EW1: 15°, 353 mm, 129.5 mm | EW3: 12°, 984 mm, 207 mm |
Three things stand out:
- Slim does not always mean a smaller angle. Both Kato Unitrack N turnouts are 15°, but the slim one diverges on 718 mm instead of 481 mm. Tillig TT also has two 15° turnouts (EW1 and EW2) with different radii.
- Slim costs length. The slim C track turnout is 236.1 mm long against 188.3 mm; in Roco Line it is 345 against 230 mm. In a station with five or six turnouts in a row, you pay that difference five or six times.
- Not every system gives you a choice. In our catalogue Piko A track has a single regular turnout (15°, 907.97 mm), which is generous to begin with.
Whether a tight turnout is a problem for your trains depends mostly on what comes straight after the diverging road. More on that in train derails at the turnout.
The symmetrical turnout (Y turnout)
On a Y turnout both tracks curve away equally, one to each side. There is no straight road and therefore no main direction: both routes run equally smoothly. It looks natural where a single line splits, at the start of a passing loop, or where a line divides into two branches.
| System | Y turnout | Per leg | Angle between the legs | Distance between the ends |
|---|---|---|---|---|
| Piko A track | 55226 | 15°, R 907.97 mm | 30° | 61.88 mm |
| Hornby | R8076 | 11.25°, R 852 mm | 22.5° | 32.74 mm |
| Tomix Fine Track N | 1240 | 15°, R 280 mm | 30° | 19.08 mm |
| LEGO Duplo | 51943c01 | 30°, R 256 mm | 60° | 68.59 mm |
On Piko, each leg is as generous as the diverging road of the regular 55220 turnout. A Y turnout therefore takes no more length than a regular one, but each track only turns half as far. The Hornby Y has exactly the angle of the standard R8072 turnout (22.5°) in total, split over two legs of 11.25°.
With toy track such as Duplo, the Y turnout is the only turnout there is. The Auto-designer builds a passing loop there from two Y turnouts, with the train leaving along one leg and returning along the other.
The three-way turnout
A three-way turnout has three exits: straight on, left and right. In our catalogue, most systems give the two side roads the same angle and radius as the regular turnout, as with Märklin C track 24630 (24.3°, 437.5 mm), Märklin K track 2270 and Piko A track 55225. Märklin M track names it a symmetrical three-way turnout outright (5214). Two exceptions: Roco Line's 42454 is 287.5 mm long against 230 mm for the regular turnout, and the Minitrix one (14940) follows the slimmer 14954 turnout (15°) rather than the 24° standard turnout.
The gain is length. Two C track turnouts in a row are 2 x 188.3 = 376.6 mm long; a three-way turnout does the same job in 188.3 mm. That is why you mostly see it in a fan of sidings, a yard or a loco depot. The downside: a three-way turnout has two motors, and you cannot move the two branches apart later.
The curved turnout
On a curved turnout both tracks bend the same way: an inner curve and an outer curve. It lets you branch off in the middle of a curve without breaking it. That helps when your straight is too short for a passing loop: you put part of the loop in the curve instead.
In our catalogue the inner road always equals a regular 30° curve, and the outer road ends on the next circle of the system:
- Märklin C track and Trix C track: 24671/24672 and 62671/62672 from R1 (360 mm) to R2 (437.5 mm); the slim 24771/24772 and 62771/62772 from R3 to R4.
- Märklin K track: 2268/2269 from the standard radius I (360 mm) to standard radius II (424.6 mm).
- Märklin M track: 5141/5142 from R1 (360 mm) to R2 (437.4 mm).
- Märklin Z: 8568/8569 from R2 (195 mm) to R3 (220 mm).
Fleischmann piccolo has one too (9174/9175), but in our catalogue its outer road does not end neatly on a circle; you lay that one yourself.
Turnouts in TrackDrawer
The Auto-designer works with your system's turnout pattern: the left and right standard turnouts, the matching counter curve and compensation piece, plus usable curved turnouts. Slim turnouts, three-way turnouts and a double slip do not go into its variants; you place those yourself in the editor, where the check shows straight away whether everything closes and nothing overlaps. Enter your track, let the Auto-designer lay a first plan, and then swap a few turnouts for slimmer ones wherever you like.
