All N-scale variants
The full catalogue of N-scale module variants currently sanctioned by the Australian guidelines fits on one page. Every entry below shares the same end-of-module geometry — the joins are interchangeable — so any combination can be assembled into a layout.
| Variant | Base size | Track or radii | Use case |
|---|---|---|---|
| Standard outside corner | 365 × 365 mm | 282 / 315 R | 90° turn at the end of the layout. |
| Double corner | 365 × 732 mm | Single piece | Replaces two standard corners back-to-back as a single unit. |
| Junction module | 365 × 596 mm | 102 mm filler — 22 mm short of double | Pair opposite a double corner. The filler may be cut Unitrack, a Kato #20-050 expansion piece (78–108 mm), or a #20-091 short pack (29 + 29 + 45.5 mm with 0.75 mm stretch). |
| Inside corner | Based on 290 mm sq. | 282 R + straights | L-shape layouts; skyboards run along the top and right edges. |
| T-1-TRAK · single track | 308 × 300 mm box | One main | Branchline use; choose Inner or Outer running line. Transition modules required if mixing with double-track standard. |
| Non-Unitrack (Method 1) | Any straight | #20-045 at each end | Peco or Atlas code 80 between Kato adaptor pieces. 3 mm cork underlay. Atlas code 55 is incompatible. |
| Non-Unitrack (Method 2) | Any straight | 62 mm Unitrack | Remove one Unijoiner with a rerailer; cork is shaped to slide inside the Unitrack ballast. |
| Non-Unitrack (Method 3) | Any straight | Split base | Cut a 124 mm Unitrack base in half from the underside; slide the rails out and replace with Peco code 80 sleeper webbing. |
| Mini-T outside corner | 290 mm sq. | 282 R | Corner can optionally be chamfered. |
Every variant in the table conforms to the universal end-of-module geometry — track centres at 33 mm, set back 38 mm from the front edge, with 1 mm of railhead overhanging the module ends to take a Unijoiner.
Future variants
The published guidelines flag several variants that are not yet specified. Builders are asked to keep them club-internal until the standard is updated — which keeps everyone on the same geometry when the formal definition does land.
The current Australian T-TRAK guidelines list End-Loop (a reverse-loop module) and HO single-track as planned but not yet specified.
Modules built to either of those provisional patterns are best treated as club-internal until the official standard catches up — at which point the published dimensions take precedence over any local interpretation.
Junction module — assembly note
The junction module is one of the few variants that does not stand alone geometrically. A double-length straight is 365 × 618 mm; the junction is 365 × 596 mm. That is exactly 22 mm shorter than a double straight along the running direction.
Because the junction is 22 mm short of a true double, dropping one into a layout shifts the loop's running length by that amount. To put the geometry back on the regular grid, the junction must be paired with a complementary module on the opposite side of the loop — the conventional choice is a double corner.
Inside the junction itself, the missing 22 mm is taken up by the 102 mm filler in the running track. That filler can be cut Unitrack, an expansion piece (Kato #20-050, 78–108 mm) or a short pack (#20-091, three pieces totalling 103.5 mm with the 0.75 mm stretch the standard allows).
If you skip the partner module, you will discover the discrepancy when the final corners refuse to meet. The fix at that point is to insert one of the same fillers on the opposite side — but at that stage of setup you would rather not be cutting Unitrack on a trestle table.